Protein Kinases, catalytic domain; The protein kinase superfamily is mainly composed of the catalytic domains of serine/threonine-specific and tyrosine-specific protein kinases. It also includes RIO kinases, which are atypical serine protein kinases, aminoglycoside phosphotransferases, and choline kinases. These proteins catalyze the transfer of the gamma-phosphoryl group from ATP to hydroxyl groups in specific substrates such as serine, threonine, or tyrosine residues of proteins.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 555 YEIRWRVIESISPDGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 634
Cdd:cd05105     1 YEIRWRVIESISPDGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 635 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDSFMSQHPEKPKKDLDIFGLNPAD 714
Cdd:cd05105    81 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDNFLSRHPEKPKKDLDIFGINPAD 160

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1113820510 715 ESTRSYVILSFENNGDYMDMKQADTTQYVPMLERKEVSKYSDIQRSLYDRPASYKKKS 772
Cdd:cd05105   161 ESTRSYVILSFENKGDYMDMKQADTTQYVPMLEIKEASKYSDIQRSNYDRPASYKGSN 218

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 212 SELNLEMDARQTVYKAGETIVVTCAVFNNEVVDLQWTYPGEVRNKGITMLEEIKLPSIKLVYTLTVPKATVKDSGEYECA 291
Cdd:cd05861     1 SSINVEMEAVKTVVRQGETITLMCIVIGNEVVDLEWTYPGKESGRGIEPVEEFKVPPYHLVYTLTIPSATLEDSGTYECA 80

                          90
                  ....*....|....*....
gi 1113820510 292 ARQATKEVKEMKRVTISVH 310
Cdd:cd05861    81 VTEATNDHQDEKKINITVH 99

Catalytic domain of the Protein Tyrosine Kinase, Platelet Derived Growth Factor Receptor alpha; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. PDGFR alpha is a receptor PTK (RTK) containing an extracellular ligand-binding region with five immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding to its ligands, the PDGFs, leads to receptor dimerization, trans phosphorylation and activation, and intracellular signaling. PDGFR alpha forms homodimers or heterodimers with PDGFR beta, depending on the nature of the PDGF ligand. PDGF-AA, PDGF-AB, and PDGF-CC induce PDGFR alpha homodimerization. PDGFR signaling plays many roles in normal embryonic development and adult physiology. PDGFR alpha signaling is important in the formation of lung alveoli, intestinal villi, mesenchymal dermis, and hair follicles, as well as in the development of oligodendrocytes, retinal astrocytes, neural crest cells, and testicular cells. Aberrant PDGFR alpha expression is associated with some human cancers. Mutations in PDGFR alpha have been found within a subset of gastrointestinal stromal tumors (GISTs). An active fusion protein FIP1L1-PDGFR alpha, derived from interstitial deletion, is associated with idiopathic hypereosinophilic syndrome and chronic eosinophilic leukemia. The PDGFR alpha subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 555 YEIRWRVIESISPDGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 634
Cdd:cd05105     1 YEIRWRVIESISPDGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 635 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDSFMSQHPEKPKKDLDIFGLNPAD 714
Cdd:cd05105    81 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDNFLSRHPEKPKKDLDIFGINPAD 160

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1113820510 715 ESTRSYVILSFENNGDYMDMKQADTTQYVPMLERKEVSKYSDIQRSLYDRPASYKKKS 772
Cdd:cd05105   161 ESTRSYVILSFENKGDYMDMKQADTTQYVPMLEIKEASKYSDIQRSNYDRPASYKGSN 218

Immunoglobulin (Ig)-like domain of platelet-derived growth factor (PDGF) receptors (R), alpha and beta; member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of platelet-derived growth factor (PDGF) receptors (R), alpha (also known as cluster of differentiation (CD) 140a), and beta (also known as CD140b). PDGF is a potent mitogen for connective tissue cells. PDGF-stimulated processes are mediated by three different PDGFs (PDGF-A,PDGF-B, and PDGF-C). PDGFRalpha binds to all three PDGFs, whereas the PDGFRbeta binds only to PDGF-B. PDGFRs alpha and beta have similar organization: an extracellular component with five Ig-like domains, a transmembrane segment, and a cytoplasmic portion having protein tyrosine kinase activity. In mice, PDGFRalpha and PDGFRbeta are essential for normal development.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 212 SELNLEMDARQTVYKAGETIVVTCAVFNNEVVDLQWTYPGEVRNKGITMLEEIKLPSIKLVYTLTVPKATVKDSGEYECA 291
Cdd:cd05861     1 SSINVEMEAVKTVVRQGETITLMCIVIGNEVVDLEWTYPGKESGRGIEPVEEFKVPPYHLVYTLTIPSATLEDSGTYECA 80

                          90
                  ....*....|....*....
gi 1113820510 292 ARQATKEVKEMKRVTISVH 310
Cdd:cd05861    81 VTEATNDHQDEKKINITVH 99

Protein kinase; unclassified specificity; Phosphotransferases. The specificity of this class of kinases can not be predicted. Possible dual-specificity Ser/Thr/Tyr kinase.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510  593 LVLGRILGSGAFGKVVEGTAYGLSRSQPVmKVAVKMLKPTARSSEKQALMSELKIMTHLGpHLNIVNLLGACTKSGPIYI 672
Cdd:smart00221   1 LTLGKKLGEGAFGEVYKGTLKGKGDGKEV-EVAVKTLKEDASEQQIEEFLREARIMRKLD-HPNIVKLLGVCTEEEPLMI 78

                           90       100
                   ....*....|....*....|...
gi 1113820510  673 ITEYCFYGDLVNYLHKNRDSFMS 695
Cdd:smart00221  79 VMEYMPGGDLLDYLRKNRPKELS 101

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1113820510 334 EFVVEVQAYPTPRISWLKDNLTLIENLTEITTDVQksqetrYQSKLKLIRAKEEDSGHYTIIVQN 398
Cdd:pfam13927  20 TLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSG------SNSTLTISNVTRSDAGTYTCVASN 78

Serine/threonine protein kinase [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 590 RDGLVLGRILGSGAFGKVVEGTAYGLSRsqpvmKVAVKMLKPTARSSEK--QALMSELKIMTHLGpHLNIVNLLGACTKS 667
Cdd:COG0515     6 LGRYRILRLLGRGGMGVVYLARDLRLGR-----PVALKVLRPELAADPEarERFRREARALARLN-HPNIVRVYDVGEED 79

                          90       100
                  ....*....|....*....|...
gi 1113820510 668 GPIYIITEYCFYGDLVNYLHKNR 690
Cdd:COG0515    80 GRPYLVMEYVEGESLADLLRRRG 102

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1113820510  28 PSILPNENEKIVQLNSSFSLRCVGES----EVSWQHPMSEEDDPNVEIRSEENNSGlfvtVLEVVNASAAHTGWYTC 100
Cdd:pfam13927   2 PVITVSPSSVTVREGETVTLTCEATGspppTITWYKNGEPISSGSTRSRSLSGSNS----TLTISNVTRSDAGTYTC 74

Catalytic domain of the Protein Tyrosine Kinase, Platelet Derived Growth Factor Receptor alpha; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. PDGFR alpha is a receptor PTK (RTK) containing an extracellular ligand-binding region with five immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding to its ligands, the PDGFs, leads to receptor dimerization, trans phosphorylation and activation, and intracellular signaling. PDGFR alpha forms homodimers or heterodimers with PDGFR beta, depending on the nature of the PDGF ligand. PDGF-AA, PDGF-AB, and PDGF-CC induce PDGFR alpha homodimerization. PDGFR signaling plays many roles in normal embryonic development and adult physiology. PDGFR alpha signaling is important in the formation of lung alveoli, intestinal villi, mesenchymal dermis, and hair follicles, as well as in the development of oligodendrocytes, retinal astrocytes, neural crest cells, and testicular cells. Aberrant PDGFR alpha expression is associated with some human cancers. Mutations in PDGFR alpha have been found within a subset of gastrointestinal stromal tumors (GISTs). An active fusion protein FIP1L1-PDGFR alpha, derived from interstitial deletion, is associated with idiopathic hypereosinophilic syndrome and chronic eosinophilic leukemia. The PDGFR alpha subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 555 YEIRWRVIESISPDGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 634
Cdd:cd05105     1 YEIRWRVIESISPDGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 635 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDSFMSQHPEKPKKDLDIFGLNPAD 714
Cdd:cd05105    81 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDNFLSRHPEKPKKDLDIFGINPAD 160

                         170       180       190       200       210
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1113820510 715 ESTRSYVILSFENNGDYMDMKQADTTQYVPMLERKEVSKYSDIQRSLYDRPASYKKKS 772
Cdd:cd05105   161 ESTRSYVILSFENKGDYMDMKQADTTQYVPMLEIKEASKYSDIQRSNYDRPASYKGSN 218

Catalytic domain of the Protein Tyrosine Kinases, Platelet Derived Growth Factor Receptors; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The PDGFR subfamily consists of PDGFR alpha, PDGFR beta, KIT, CSF-1R, the mammalian FLT3, and similar proteins. They are receptor PTKs (RTKs) containing an extracellular ligand-binding region with five immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. PDGFR kinase domains are autoinhibited by their juxtamembrane regions containing tyr residues. The binding to their ligands leads to receptor dimerization, trans phosphorylation and activation, and intracellular signaling. PDGFR subfamily receptors are important in the development of a variety of cells. PDGFRs are expressed in a many cells including fibroblasts, neurons, endometrial cells, mammary epithelial cells, and vascular smooth muscle cells. PDGFR signaling is critical in normal embryonic development, angiogenesis, and wound healing. Kit is important in the development of melanocytes, germ cells, mast cells, hematopoietic stem cells, the interstitial cells of Cajal, and the pacemaker cells of the GI tract. CSF-1R signaling is critical in the regulation of macrophages and osteoclasts. Mammalian FLT3 plays an important role in the survival, proliferation, and differentiation of stem cells. The PDGFR subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase .

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 555 YEIRWRVIESISpdGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 634
Cdd:cd05055     1 YEVRWKVIESIN--GNEYVYIDPTQLPYDLKWEFPRNNLSFGKTLGAGAFGKVVEATAYGLSKSDAVMKVAVKMLKPTAH 78

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1113820510 635 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDSFMS 695
Cdd:cd05055    79 SSEREALMSELKIMSHLGNHENIVNLLGACTIGGPILVITEYCCYGDLLNFLRRKRESFLT 139

Catalytic domain of the Protein Tyrosine Kinase, Kit; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Kit is important in the development of melanocytes, germ cells, mast cells, hematopoietic stem cells, the interstitial cells of Cajal, and the pacemaker cells of the GI tract. Kit signaling is involved in major cellular functions including cell survival, proliferation, differentiation, adhesion, and chemotaxis. Mutations in Kit, which result in constitutive ligand-independent activation, are found in human cancers such as gastrointestinal stromal tumor (GIST) and testicular germ cell tumor (TGCT). The aberrant expression of Kit and/or SCF is associated with other tumor types such as systemic mastocytosis and cancers of the breast, neurons, lung, prostate, colon, and rectum. Although the structure of the human Kit catalytic domain is known, it is excluded from this specific alignment model because it contains a deletion in its sequence. Kit is a member of the Platelet Derived Growth Factor Receptor (PDGFR) subfamily of proteins, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with five immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of Kit to its ligand, the stem-cell factor (SCF), leads to receptor dimerization, trans phosphorylation and activation, and intracellular signaling. The Kit subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 555 YEIRWRVIESIspDGHEYIYVDPMQLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTAR 634
Cdd:cd05104     1 YEIQWKVVEEI--NGNNYVYIDPTQLPYDHKWEFPRDRLRFGKTLGAGAFGKVVEATAYGLAKADSAMTVAVKMLKPSAH 78

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 635 SSEKQALMSELKIMTHLGPHLNIVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDSFMSQHPEKpkkdldifglnPAD 714
Cdd:cd05104    79 STEREALMSELKVLSYLGNHINIVNLLGACTVGGPTLVITEYCCYGDLLNFLRRKRDSFICPKFED-----------LAE 147

                         170       180
                  ....*....|....*....|....*..
gi 1113820510 715 ESTRSYVILSFENNGD----YMDMKQA 737
Cdd:cd05104   148 AALYRNLLHQREMACDslneYMDMKPS 174

Immunoglobulin (Ig)-like domain of platelet-derived growth factor (PDGF) receptors (R), alpha and beta; member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of platelet-derived growth factor (PDGF) receptors (R), alpha (also known as cluster of differentiation (CD) 140a), and beta (also known as CD140b). PDGF is a potent mitogen for connective tissue cells. PDGF-stimulated processes are mediated by three different PDGFs (PDGF-A,PDGF-B, and PDGF-C). PDGFRalpha binds to all three PDGFs, whereas the PDGFRbeta binds only to PDGF-B. PDGFRs alpha and beta have similar organization: an extracellular component with five Ig-like domains, a transmembrane segment, and a cytoplasmic portion having protein tyrosine kinase activity. In mice, PDGFRalpha and PDGFRbeta are essential for normal development.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 212 SELNLEMDARQTVYKAGETIVVTCAVFNNEVVDLQWTYPGEVRNKGITMLEEIKLPSIKLVYTLTVPKATVKDSGEYECA 291
Cdd:cd05861     1 SSINVEMEAVKTVVRQGETITLMCIVIGNEVVDLEWTYPGKESGRGIEPVEEFKVPPYHLVYTLTIPSATLEDSGTYECA 80

                          90
                  ....*....|....*....
gi 1113820510 292 ARQATKEVKEMKRVTISVH 310
Cdd:cd05861    81 VTEATNDHQDEKKINITVH 99

Catalytic domain of the Protein Tyrosine Kinase, Vascular Endothelial Growth Factor Receptor 3; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. VEGFR3 (or Flt4) preferentially binds the ligands VEGFC and VEGFD. VEGFR3 is essential for lymphatic endothelial cell (EC) development and function. It has been shown to regulate adaptive immunity during corneal transplantation. VEGFR3 is upregulated on blood vascular ECs in pathological conditions such as vascular tumors and the periphery of solid tumors. It plays a role in cancer progression and lymph node metastasis. Missense mutations in the VEGFR3 gene are associated with primary human lymphedema. VEGFR3 is a member of the VEGFR subfamily of proteins, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with seven immunoglobulin (Ig)-like domains, a transmembrane segment, and an intracellular catalytic domain. In VEGFR3, the fifth Ig-like domain is replaced by a disulfide bridge. The binding of VEGFRs to their ligands, the VEGFs, leads to receptor dimerization, activation, and intracellular signaling. The VEGFR3 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 585 RWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTARSSEKQALMSELKIMTHLGPHLNIVNLLGAC 664
Cdd:cd05102     1 QWEFPRDRLRLGKVLGHGAFGKVVEASAFGIDKSSSCETVAVKMLKEGATASEHKALMSELKILIHIGNHLNVVNLLGAC 80

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1113820510 665 TKS-GPIYIITEYCFYGDLVNYLHKNRDSFMSQHPEKPK 702
Cdd:cd05102    81 TKPnGPLMVIVEFCKYGNLSNFLRAKREGFSPYRERSPR 119

Catalytic domain of the Protein Tyrosine Kinase, Vascular Endothelial Growth Factor Receptor 2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. VEGFR2 (or Flk1) binds the ligands VEGFA, VEGFC, VEGFD and VEGFE. VEGFR2 signaling is implicated in all aspects of normal and pathological vascular endothelial cell biology. It induces a variety of cellular effects including migration, survival, and proliferation. It is critical in regulating embryonic vascular development and angiogenesis. VEGFR2 is the major signal transducer in pathological angiogenesis including cancer and diabetic retinopathy, and is a target for inhibition in cancer therapy. The carboxyl terminus of VEGFR2 plays an important role in its autophosphorylation and activation. VEGFR2 is a member of the VEGFR subfamily of proteins, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with seven immunoglobulin (Ig)-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of VEGFRs to their ligands, the VEGFs, leads to receptor dimerization, activation, and intracellular signaling. The VEGFR2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 585 RWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTARSSEKQALMSELKIMTHLGPHLNIVNLLGAC 664
Cdd:cd05103     1 KWEFPRDRLKLGKPLGRGAFGQVIEADAFGIDKTATCRTVAVKMLKEGATHSEHRALMSELKILIHIGHHLNVVNLLGAC 80

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1113820510 665 TK-SGPIYIITEYCFYGDLVNYLHKNRDSFMSQHPEKPK 702
Cdd:cd05103    81 TKpGGPLMVIVEFCKFGNLSAYLRSKRSEFVPYKTKGAR 119

Catalytic domain of the Protein Tyrosine Kinases, Fibroblast Growth Factor Receptors; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The FGFR subfamily consists of FGFR1, FGFR2, FGFR3, FGFR4, and similar proteins. They are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, and to heparin/heparan sulfate (HS) results in the formation of a ternary complex, which leads to receptor dimerization and activation, and intracellular signaling. There are at least 23 FGFs and four types of FGFRs. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. FGF/FGFR signaling is important in the regulation of embryonic development, homeostasis, and regenerative processes. Depending on the cell type and stage, FGFR signaling produces diverse cellular responses including proliferation, growth arrest, differentiation, and apoptosis. Aberrant signaling leads to many human diseases such as skeletal, olfactory, and metabolic disorders, as well as cancer. The FGFR subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase .

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 580 LPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQP-VMKVAVKMLKPTARSSEKQALMSELKIMTHLGPHLNIV 658
Cdd:cd05053     1 LPLDPEWELPRDRLTLGKPLGEGAFGQVVKAEAVGLDNKPNeVVTVAVKMLKDDATEKDLSDLVSEMEMMKMIGKHKNII 80

                          90       100       110
                  ....*....|....*....|....*....|..
gi 1113820510 659 NLLGACTKSGPIYIITEYCFYGDLVNYLHKNR 690
Cdd:cd05053    81 NLLGACTQDGPLYVVVEYASKGNLREFLRARR 112

Catalytic domain of the Protein Tyrosine Kinase, Fibroblast Growth Factor Receptor 4; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Unlike other FGFRs, there is only one splice form of FGFR4. It binds FGF1, FGF2, FGF6, FGF19, and FGF23. FGF19 is a selective ligand for FGFR4. Although disruption of FGFR4 in mice causes no obvious phenotype, in vivo inhibition of FGFR4 in cultured skeletal muscle cells resulted in an arrest of muscle progenitor differentiation. FGF6 and FGFR4 are uniquely expressed in myofibers and satellite cells. FGF6/FGFR4 signaling appears to play a key role in the regulation of muscle regeneration. A polymorphism in FGFR4 is found in head and neck squamous cell carcinoma. FGFR4 is part of the FGFR subfamily, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, results in receptor dimerization and activation, and intracellular signaling. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. The FGFR4 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 580 LPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQP--VMKVAVKMLKPTARSSEKQALMSELKIMTHLGPHLNI 657
Cdd:cd05099     1 LPLDPKWEFPRDRLVLGKPLGEGCFGQVVRAEAYGIDKSRPdqTVTVAVKMLKDNATDKDLADLISEMELMKLIGKHKNI 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*
gi 1113820510 658 VNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDSFMSQHPEKPK 702
Cdd:cd05099    81 INLLGVCTQEGPLYVIVEYAAKGNLREFLRARRPPGPDYTFDITK 125

Catalytic domain of Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. They can be classified into receptor and non-receptor tyr kinases. PTKs play important roles in many cellular processes including, lymphocyte activation, epithelium growth and maintenance, metabolism control, organogenesis regulation, survival, proliferation, differentiation, migration, adhesion, motility, and morphogenesis. Receptor tyr kinases (RTKs) are integral membrane proteins which contain an extracellular ligand-binding region, a transmembrane segment, and an intracellular tyr kinase domain. RTKs are usually activated through ligand binding, which causes dimerization and autophosphorylation of the intracellular tyr kinase catalytic domain, leading to intracellular signaling. Some RTKs are orphan receptors with no known ligands. Non-receptor (or cytoplasmic) tyr kinases are distributed in different intracellular compartments and are usually multi-domain proteins containing a catalytic tyr kinase domain as well as various regulatory domains such as SH3 and SH2. PTKs are usually autoinhibited and require a mechanism for activation. In many PTKs, the phosphorylation of tyr residues in the activation loop is essential for optimal activity. Aberrant expression of PTKs is associated with many development abnormalities and cancers.The PTK family is part of a larger superfamily that includes the catalytic domains of serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 597 RILGSGAFGKVVEGTAYGLSrsQPVMKVAVKMLKPTARSSEKQALMSELKIMTHLGpHLNIVNLLGACTKSGPIYIITEY 676
Cdd:cd00192     1 KKLGEGAFGEVYKGKLKGGD--GKTVDVAVKTLKEDASESERKDFLKEARVMKKLG-HPNVVRLLGVCTEEEPLYLVMEY 77

                          90
                  ....*....|....*....
gi 1113820510 677 CFYGDLVNYLHKNRDSFMS 695
Cdd:cd00192    78 MEGGDLLDFLRKSRPVFPS 96

Catalytic domain of the Protein Tyrosine Kinase, Fibroblast Growth Factor Receptor 1; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Alternative splicing of FGFR1 transcripts produces a variety of isoforms, which are differentially expressed in cells. FGFR1 binds the ligands, FGF1 and FGF2, with high affinity and has also been reported to bind FGF4, FGF6, and FGF9. FGFR1 signaling is critical in the control of cell migration during embryo development. It promotes cell proliferation in fibroblasts. Nuclear FGFR1 plays a role in the regulation of transcription. Mutations, insertions or deletions of FGFR1 have been identified in patients with Kallman's syndrome (KS), an inherited disorder characterized by hypogonadotropic hypogonadism and loss of olfaction. Aberrant FGFR1 expression has been found in some human cancers including 8P11 myeloproliferative syndrome (EMS), breast cancer, and pancreatic adenocarcinoma. FGFR1 is part of the FGFR subfamily, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, results in receptor dimerization and activation, and intracellular signaling. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. The FGFR1 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 579 QLPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQP--VMKVAVKMLKPTARSSEKQALMSELKIMTHLGPHLN 656
Cdd:cd05098     1 ELPEDPRWELPRDRLVLGKPLGEGCFGQVVLAEAIGLDKDKPnrVTKVAVKMLKSDATEKDLSDLISEMEMMKMIGKHKN 80

                          90       100       110
                  ....*....|....*....|....*....|....
gi 1113820510 657 IVNLLGACTKSGPIYIITEYCFYGDLVNYLHKNR 690
Cdd:cd05098    81 IINLLGACTQDGPLYVIVEYASKGNLREYLQARR 114

Catalytic domain of the Protein Tyrosine Kinase, Fibroblast Growth Factor Receptor 3; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Many FGFR3 splice variants have been reported with the IIIb and IIIc isoforms being the predominant forms. FGFR3 IIIc is the isoform expressed in chondrocytes, the cells affected in dwarfism, while IIIb is expressed in epithelial cells. FGFR3 ligands include FGF1, FGF2, FGF4, FGF8, FGF9, and FGF23. It is a negative regulator of long bone growth. In the cochlear duct and in the lens, FGFR3 is involved in differentiation while it appears to have a role in cell proliferation in epithelial cells. Germline mutations in FGFR3 are associated with skeletal disorders including several forms of dwarfism. Some missense mutations are associated with multiple myeloma and carcinomas of the bladder and cervix. Overexpression of FGFR3 is found in thyroid carcinoma. FGFR3 is part of the FGFR subfamily, which are receptor PTKs (RTKs) containing an extracellular ligand-binding region with three immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. The binding of FGFRs to their ligands, the FGFs, results in receptor dimerization and activation, and intracellular signaling. The binding of FGFs to FGFRs is promiscuous, in that a receptor may be activated by several ligands and a ligand may bind to more that one type of receptor. The FGFR3 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 580 LPYDSRWEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQP--VMKVAVKMLKPTARSSEKQALMSELKIMTHLGPHLNI 657
Cdd:cd05100     1 LPADPKWELSRTRLTLGKPLGEGCFGQVVMAEAIGIDKDKPnkPVTVAVKMLKDDATDKDLSDLVSEMEMMKMIGKHKNI 80

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 1113820510 658 VNLLGACTKSGPIYIITEYCFYGDLVNYLHKNRDSFM 694
Cdd:cd05100    81 INLLGACTQDGPLYVLVEYASKGNLREYLRARRPPGM 117

Catalytic domain of Insulin Receptor-like Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The InsR subfamily is composed of InsR, Insulin-like Growth Factor-1 Receptor (IGF-1R), and similar proteins. InsR and IGF-1R are receptor PTKs (RTKs) composed of two alphabeta heterodimers. Binding of the ligand (insulin, IGF-1, or IGF-2) to the extracellular alpha subunit activates the intracellular tyr kinase domain of the transmembrane beta subunit. Receptor activation leads to autophosphorylation, stimulating downstream kinase activities, which initiate signaling cascades and biological function. InsR and IGF-1R, which share 84% sequence identity in their kinase domains, display physiologically distinct yet overlapping functions in cell growth, differentiation, and metabolism. InsR activation leads primarily to metabolic effects while IGF-1R activation stimulates mitogenic pathways. In cells expressing both receptors, InsR/IGF-1R hybrids are found together with classical receptors. Both receptors can interact with common adaptor molecules such as IRS-1 and IRS-2. The InsR-like subfamily is part of a larger superfamily that includes the catalytic domains of serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 586 WEFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTARSSEKQALMSELKIMTHLGPHlNIVNLLGACT 665
Cdd:cd05032     1 WELPREKITLIRELGQGSFGMVYEGLAKGVVKGEPETRVAIKTVNENASMRERIEFLNEASVMKEFNCH-HVVRLLGVVS 79

                          90       100
                  ....*....|....*....|....*
gi 1113820510 666 KSGPIYIITEYCFYGDLVNYLHKNR 690
Cdd:cd05032    80 TGQPTLVVMELMAKGDLKSYLRSRR 104

Catalytic domain of the Protein Tyrosine Kinases, Tropomyosin Related Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The Trk subfamily consists of TrkA, TrkB, TrkC, and similar proteins. They are receptor PTKs (RTKs) containing an extracellular region with arrays of leucine-rich motifs flanked by two cysteine-rich clusters followed by two immunoglobulin-like domains, a transmembrane segment, and an intracellular catalytic domain. Binding to their ligands, the nerve growth factor (NGF) family of neutrotrophins, leads to Trk receptor oligomerization and activation of the catalytic domain. Trk receptors are mainly expressed in the peripheral and central nervous systems. They play important roles in cell fate determination, neuronal survival and differentiation, as well as in the regulation of synaptic plasticity. Altered expression of Trk receptors is associated with many human diseases. The Trk subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 587 EFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTARSSEKQALMSELKIMTHLgPHLNIVNLLGACTK 666
Cdd:cd05049     1 HIKRDTIVLKRELGEGAFGKVFLGECYNLEPEQDKMLVAVKTLKDASSPDARKDFEREAELLTNL-QHENIVKFYGVCTE 79

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1113820510 667 SGPIYIITEYCFYGDLVNYL--HKNRDSFMSQHPEKPKK 703
Cdd:cd05049    80 GDPLLMVFEYMEHGDLNKFLrsHGPDAAFLASEDSAPGE 118

Catalytic domain of Protein Kinases; PKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine or tyrosine residues on protein substrates. PKs make up a large family of serine/threonine kinases (STKs), protein tyrosine kinases (PTKs), and dual-specificity PKs that phosphorylate both serine/threonine and tyrosine residues of target proteins. Majority of protein phosphorylation occurs on serine residues while only 1% occurs on tyrosine residues. Protein phosphorylation is a mechanism by which a wide variety of cellular proteins, such as enzymes and membrane channels, are reversibly regulated in response to certain stimuli. PKs often function as components of signal transduction pathways in which one kinase activates a second kinase, which in turn, may act on other kinases; this sequential action transmits a signal from the cell surface to target proteins, which results in cellular responses. The PK family is one of the largest known protein families with more than 100 homologous yeast enzymes and more than 500 human proteins. A fraction of PK family members are pseudokinases that lack crucial residues for catalytic activity. The mutiplicity of kinases allows for specific regulation according to substrate, tissue distribution, and cellular localization. PKs regulate many cellular processes including proliferation, division, differentiation, motility, survival, metabolism, cell-cycle progression, cytoskeletal rearrangement, immunity, and neuronal functions. Many kinases are implicated in the development of various human diseases including different types of cancer. The PK family is part of a larger superfamily that includes the catalytic domains of RIO kinases, aminoglycoside phosphotransferase, choline kinase, phosphoinositide 3-kinase (PI3K), and actin-fragmin kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 599 LGSGAFGKVVEGTAYGLSRsqpvmKVAVKMLKPTARSSEKQALMSELKIMTHLgPHLNIVNLLGACTKSGPIYIITEYCF 678
Cdd:cd00180     1 LGKGSFGKVYKARDKETGK-----KVAVKVIPKEKLKKLLEELLREIEILKKL-NHPNIVKLYDVFETENFLYLVMEYCE 74

                          90
                  ....*....|....*
gi 1113820510 679 YGDLVNYLHKNRDSF 693
Cdd:cd00180    75 GGSLKDLLKENKGPL 89

Serine/Threonine protein kinases, catalytic domain; Phosphotransferases. Serine or threonine-specific kinase subfamily.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510  595 LGRILGSGAFGKVVEGTAYGLSRsqpvmKVAVKMLKPTARSSEKQALMSELKIMTHLGpHLNIVNLLGACTKSGPIYIIT 674
Cdd:smart00220   3 ILEKLGEGSFGKVYLARDKKTGK-----LVAIKVIKKKKIKKDRERILREIKILKKLK-HPNIVRLYDVFEDEDKLYLVM 76

                           90
                   ....*....|....*.
gi 1113820510  675 EYCFYGDLVNYLHKNR 690
Cdd:smart00220  77 EYCEGGDLFDLLKKRG 92

Catalytic domain of the Protein Tyrosine Kinases, Anaplastic Lymphoma Kinase and Leukocyte Tyrosine Kinase; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyr residues in protein substrates. ALK and LTK are orphan receptor PTKs (RTKs) whose ligands are not yet well-defined. ALK appears to play an important role in mammalian neural development as well as visceral muscle differentiation in Drosophila. ALK is aberrantly expressed as fusion proteins, due to chromosomal translocations, in about 60% of anaplastic large cell lymphomas (ALCLs). ALK fusion proteins are also found in rare cases of diffuse large B cell lymphomas (DLBCLs). LTK is mainly expressed in B lymphocytes and neuronal tissues. It is important in cell proliferation and survival. Transgenic mice expressing TLK display retarded growth and high mortality rate. In addition, a polymorphism in mouse and human LTK is implicated in the pathogenesis of systemic lupus erythematosus. RTKs contain an extracellular ligand-binding domain, a transmembrane region, and an intracellular tyr kinase domain. They are usually activated through ligand binding, which causes dimerization and autophosphorylation of the intracellular tyr kinase catalytic domain. The ALK/LTK subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 587 EFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKML-KPTARSSEKQALMSELkIMTHLGpHLNIVNLLGACT 665
Cdd:cd05036     2 EVPRKNLTLIRALGQGAFGEVYEGTVSGMPGDPSPLQVAVKTLpELCSEQDEMDFLMEAL-IMSKFN-HPNIVRCIGVCF 79

                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1113820510 666 KSGPIYIITEYCFYGDLVNYLHKNRDsfmsqHPEKP 701
Cdd:cd05036    80 QRLPRFILLELMAGGDLKSFLRENRP-----RPEQP 110

Catalytic domain of Fyn-related kinase-like Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Frk and Srk are members of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. Frk, also known as Rak, is specifically expressed in liver, lung, kidney, intestine, mammary glands, and the islets of Langerhans. Rodent homologs were previously referred to as GTK (gastrointestinal tyr kinase), BSK (beta-cell Src-like kinase), or IYK (intestinal tyr kinase). Studies in mice reveal that Frk is not essential for viability. It plays a role in the signaling that leads to cytokine-induced beta-cell death in Type I diabetes. It also regulates beta-cell number during embryogenesis and early in life. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The Frk-like subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 586 WEFPRDGLVLGRILGSGAFGKVVEGTaygLSRSQPVmkvAVKMLKPTarSSEKQALMSELKIMTHLgPHLNIVNLLGACT 665
Cdd:cd05068     3 WEIDRKSLKLLRKLGSGQFGEVWEGL---WNNTTPV---AVKTLKPG--TMDPEDFLREAQIMKKL-RHPKLIQLYAVCT 73

                          90       100       110
                  ....*....|....*....|....*....|..
gi 1113820510 666 KSGPIYIITEYCFYGDLVNYLH-KNRDSFMSQ 696
Cdd:cd05068    74 LEEPIYIITELMKHGSLLEYLQgKGRSLQLPQ 105

Catalytic domain of Discoidin Domain Receptor-like Protein Tyrosine Kinases; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. DDR-like proteins are members of the DDR subfamily, which are receptor PTKs (RTKs) containing an extracellular discoidin homology domain, a transmembrane segment, an extended juxtamembrane region, and an intracellular catalytic domain. The binding of the ligand, collagen, to DDRs results in a slow but sustained receptor activation. DDRs regulate cell adhesion, proliferation, and extracellular matrix remodeling. They have been linked to a variety of human cancers including breast, colon, ovarian, brain, and lung. There is no evidence showing that DDRs act as transforming oncogenes. They are more likely to play a role in the regulation of tumor growth and metastasis. The DDR-like subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 587 EFPRDGLVLGRILGSGAFGKVVEGTAYGLSR----------SQPVMkVAVKMLKPTARSSEKQALMSELKIMTHLGpHLN 656
Cdd:cd05097     1 EFPRQQLRLKEKLGEGQFGEVHLCEAEGLAEflgegapefdGQPVL-VAVKMLRADVTKTARNDFLKEIKIMSRLK-NPN 78

                          90       100       110
                  ....*....|....*....|....*....|
gi 1113820510 657 IVNLLGACTKSGPIYIITEYCFYGDLVNYL 686
Cdd:cd05097    79 IIRLLGVCVSDDPLCMITEYMENGDLNQFL 108

Catalytic Domain of the Protein Tyrosine Kinases, Receptor tyrosine kinase-like Orphan Receptors; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. The Ror subfamily consists of Ror1, Ror2, and similar proteins. Ror proteins are orphan receptor PTKs (RTKs) containing an extracellular region with immunoglobulin-like, cysteine-rich, and kringle domains, a transmembrane segment, and an intracellular catalytic domain. Ror RTKs are unrelated to the nuclear receptor subfamily called retinoid-related orphan receptors (RORs). RTKs are usually activated through ligand binding, which causes dimerization and autophosphorylation of the intracellular tyr kinase catalytic domain. Ror kinases are expressed in many tissues during development. They play important roles in bone and heart formation. Mutations in human Ror2 result in two different bone development genetic disorders, recessive Robinow syndrome and brachydactyly type B. Drosophila Ror is expressed only in the developing nervous system during neurite outgrowth and neuronal differentiation, suggesting a role for Drosophila Ror in neural development. More recently, mouse Ror1 and Ror2 have also been found to play an important role in regulating neurite growth in central neurons. Ror1 and Ror2 are believed to have some overlapping and redundant functions. The Ror subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 587 EFPRDGLVLGRILGSGAFGKVVEGTAYGLSRSQPVMKVAVKMLKPTARSSEKQALMSELKIMTHLgPHLNIVNLLGACTK 666
Cdd:cd05048     1 EIPLSAVRFLEELGEGAFGKVYKGELLGPSSEESAISVAIKTLKENASPKTQQDFRREAELMSDL-QHPNIVCLLGVCTK 79

                          90       100
                  ....*....|....*....|
gi 1113820510 667 SGPIYIITEYCFYGDLVNYL 686
Cdd:cd05048    80 EQPQCMLFEYMAHGDLHEFL 99

Catalytic domain of the Protein Tyrosine Kinase, Discoidin Domain Receptor 2; PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. DDR2 is a receptor PTK (RTK) containing an extracellular discoidin homology domain, a transmembrane segment, an extended juxtamembrane region, and an intracellular catalytic domain. The binding of the ligand, collagen, to DDR2 results in a slow but sustained receptor activation. DDR2 binds mostly to fibrillar collagens as well as collagen X. DDR2 is widely expressed in many tissues with the highest levels found in skeletal muscle, skin, kidney and lung. It is important in cell proliferation and development. Mice, with a deletion of DDR2, suffer from dwarfism and delayed healing of epidermal wounds. DDR2 also contributes to collagen (type I) regulation by inhibiting fibrillogenesis and altering the morphology of collagen fibers. It is also expressed in immature dendritic cells (DCs), where it plays a role in DC activation and function. The DDR2 subfamily is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase (PI3K).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1113820510 587 EFPRDGLVLGRILGSGAFGKV----VEGT--------AYGLSRSQPVMkVAVKMLKPTARSSEKQALMSELKIMTHLgPH 654
Cdd:cd05095     1 EFPRKLLTFKEKLGEGQFGEVhlceAEGMekfmdkdfALEVSENQPVL-VAVKMLRADANKNARNDFLKEIKIMSRL-KD 78

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1113820510 655 LNIVNLLGACTKSGPIYIITEYCFYGDLvnylhknrDSFMSQH-PEKPKKdldifglNPADESTRSYVILSF 725
Cdd:cd05095    79 PNIIRLLAVCITDDPLCMITEYMENGDL--------NQFLSRQqPEGQLA-------LPSNALTVSYSDLRF 135