Src homology 2 (SH2) domain found in B-cell linker (BLNK) protein and SH2 domain-containing leukocyte protein of 76 kDa (SLP-76); BLNK (also known as SLP-65 or BASH) is an important adaptor protein expressed in B-lineage cells. BLNK consists of a N-terminal sterile alpha motif (SAM) domain and a C-terminal SH2 domain. BLNK is a cytoplasmic protein, but a part of it is bound to the plasma membrane through an N-terminal leucine zipper motif and transiently bound to a cytoplasmic domain of Iga through its C-terminal SH2 domain upon B cell antigen receptor (BCR)-stimulation. A non-ITAM phosphotyrosine in Iga is necessary for the binding with the BLNK SH2 domain and/or for normal BLNK function in signaling and B cell activation. Upon phosphorylation BLNK binds Btk and PLCgamma2 through their SH2 domains and mediates PLCgamma2 activation by Btk. BLNK also binds other signaling molecules such as Vav, Grb2, Syk, and HPK1. BLNK has been shown to be necessary for BCR-mediated Ca2+ mobilization, for the activation of mitogen-activated protein kinases such as ERK, JNK, and p38 in a chicken B cell line DT40, and for activation of transcription factors such as NF-AT and NF-kappaB in human or mouse B cells. BLNK is involved in B cell development, B cell survival, activation, proliferation, and T-independent immune responses. BLNK is structurally homologous to SLP-76. SLP-76 and (linker for activation of T cells) LAT are adaptor/linker proteins in T cell antigen receptor activation and T cell development. BLNK interacts with many downstream signaling proteins that interact directly with both SLP-76 and LAT. New data suggest functional complementation of SLP-76 and LAT in T cell antigen receptor function with BLNK in BCR function. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 335 FADQEAELLGKPWYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSKQPYTLVAFFNKRVYNIPVRFIEATKQYALGKKK 414
Cdd:cd09929   1 SAEEEADLLPKEWYAGNIDRKEAEEALRRSNKDGTFLVRDSSGKDSSQPYTLMVLYNDKVYNIQIRFLENTRQYALGTGL 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|.
gi 31982209 415 NGEEYFGSVVEIVNSHQHNPLVLIDSQNNTKDSTRLKYAVK 455
Cdd:cd09929  81 RGEETFSSVAEIIEHHQKTPLLLIDGKDNTKDSTCLLYAAG 121

Src homology 2 (SH2) domain found in B-cell linker (BLNK) protein and SH2 domain-containing leukocyte protein of 76 kDa (SLP-76); BLNK (also known as SLP-65 or BASH) is an important adaptor protein expressed in B-lineage cells. BLNK consists of a N-terminal sterile alpha motif (SAM) domain and a C-terminal SH2 domain. BLNK is a cytoplasmic protein, but a part of it is bound to the plasma membrane through an N-terminal leucine zipper motif and transiently bound to a cytoplasmic domain of Iga through its C-terminal SH2 domain upon B cell antigen receptor (BCR)-stimulation. A non-ITAM phosphotyrosine in Iga is necessary for the binding with the BLNK SH2 domain and/or for normal BLNK function in signaling and B cell activation. Upon phosphorylation BLNK binds Btk and PLCgamma2 through their SH2 domains and mediates PLCgamma2 activation by Btk. BLNK also binds other signaling molecules such as Vav, Grb2, Syk, and HPK1. BLNK has been shown to be necessary for BCR-mediated Ca2+ mobilization, for the activation of mitogen-activated protein kinases such as ERK, JNK, and p38 in a chicken B cell line DT40, and for activation of transcription factors such as NF-AT and NF-kappaB in human or mouse B cells. BLNK is involved in B cell development, B cell survival, activation, proliferation, and T-independent immune responses. BLNK is structurally homologous to SLP-76. SLP-76 and (linker for activation of T cells) LAT are adaptor/linker proteins in T cell antigen receptor activation and T cell development. BLNK interacts with many downstream signaling proteins that interact directly with both SLP-76 and LAT. New data suggest functional complementation of SLP-76 and LAT in T cell antigen receptor function with BLNK in BCR function. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 335 FADQEAELLGKPWYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSKQPYTLVAFFNKRVYNIPVRFIEATKQYALGKKK 414
Cdd:cd09929   1 SAEEEADLLPKEWYAGNIDRKEAEEALRRSNKDGTFLVRDSSGKDSSQPYTLMVLYNDKVYNIQIRFLENTRQYALGTGL 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|.
gi 31982209 415 NGEEYFGSVVEIVNSHQHNPLVLIDSQNNTKDSTRLKYAVK 455
Cdd:cd09929  81 RGEETFSSVAEIIEHHQKTPLLLIDGKDNTKDSTCLLYAAG 121

SH2 domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209   347 WYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSKqpYTLVAFFNKRVYNIPVRFiEATKQYALGkkknGEEYFGSVVEI 426
Cdd:pfam00017   1 WYHGKISRQEAERLLLNGKPDGTFLVRESESTPGG--YTLSVRDDGKVKHYKIQS-TDNGGYYIS----GGVKFSSLAEL 73

                  ....
gi 31982209   427 VNSH 430
Cdd:pfam00017  74 VEHY 77

PAB1-binding protein, interacts with poly(A)-binding protein [RNA processing and modification];

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209  48 PRRDYALDSPADEEEQWSDDFDSDYENPDEHSDSEMYVMPAEETGDDSYEPPPAEQQTRVVHPALPFTRGEYVDNRSSQR 127
Cdd:COG5180 175 PPPAEKLDKVLTEPRDALKDSPEKLDRPKVEVKDEAQEEPPDLTGGADHPRPEAASSPKVDPPSTSEARSRPATVDAQPE 254

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 128 HSPPFSKTLPSKPSWPSAKARLASTLPAPNSLQKPQVPPKPKDLLEDEADYVVPVEDNDENYIHPRESSPPP-AEKAPMV 206
Cdd:COG5180 255 MRPPADAKERRRAAIGDTPAAEPPGLPVLEAGSEPQSDAPEAETARPIDVKGVASAPPATRPVRPPGGARDPgTPRPGQP 334

                       170       180       190       200       210       220       230       240
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 207 NRstKPNSSSKHMSPPGtvaGRNSGVWDSKSSLPAAPSP--LPRAGKKPATPLKTTPVPPLPNASNVCEEKPVPAERHRG 284
Cdd:COG5180 335 TE--RPAGVPEAASDAG---QPPSAYPPAEEAVPGKPLEqgAPRPGSSGGDGAPFQPPNGAPQPGLGRRGAPGPPMGAGD 409

                ....
gi 31982209 285 SSHR 288
Cdd:COG5180 410 LVQA 413

Src homology 2 (SH2) domain found in B-cell linker (BLNK) protein and SH2 domain-containing leukocyte protein of 76 kDa (SLP-76); BLNK (also known as SLP-65 or BASH) is an important adaptor protein expressed in B-lineage cells. BLNK consists of a N-terminal sterile alpha motif (SAM) domain and a C-terminal SH2 domain. BLNK is a cytoplasmic protein, but a part of it is bound to the plasma membrane through an N-terminal leucine zipper motif and transiently bound to a cytoplasmic domain of Iga through its C-terminal SH2 domain upon B cell antigen receptor (BCR)-stimulation. A non-ITAM phosphotyrosine in Iga is necessary for the binding with the BLNK SH2 domain and/or for normal BLNK function in signaling and B cell activation. Upon phosphorylation BLNK binds Btk and PLCgamma2 through their SH2 domains and mediates PLCgamma2 activation by Btk. BLNK also binds other signaling molecules such as Vav, Grb2, Syk, and HPK1. BLNK has been shown to be necessary for BCR-mediated Ca2+ mobilization, for the activation of mitogen-activated protein kinases such as ERK, JNK, and p38 in a chicken B cell line DT40, and for activation of transcription factors such as NF-AT and NF-kappaB in human or mouse B cells. BLNK is involved in B cell development, B cell survival, activation, proliferation, and T-independent immune responses. BLNK is structurally homologous to SLP-76. SLP-76 and (linker for activation of T cells) LAT are adaptor/linker proteins in T cell antigen receptor activation and T cell development. BLNK interacts with many downstream signaling proteins that interact directly with both SLP-76 and LAT. New data suggest functional complementation of SLP-76 and LAT in T cell antigen receptor function with BLNK in BCR function. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 335 FADQEAELLGKPWYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSKQPYTLVAFFNKRVYNIPVRFIEATKQYALGKKK 414
Cdd:cd09929   1 SAEEEADLLPKEWYAGNIDRKEAEEALRRSNKDGTFLVRDSSGKDSSQPYTLMVLYNDKVYNIQIRFLENTRQYALGTGL 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|.
gi 31982209 415 NGEEYFGSVVEIVNSHQHNPLVLIDSQNNTKDSTRLKYAVK 455
Cdd:cd09929  81 RGEETFSSVAEIIEHHQKTPLLLIDGKDNTKDSTCLLYAAG 121

SH2 domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209   347 WYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSKqpYTLVAFFNKRVYNIPVRFiEATKQYALGkkknGEEYFGSVVEI 426
Cdd:pfam00017   1 WYHGKISRQEAERLLLNGKPDGTFLVRESESTPGG--YTLSVRDDGKVKHYKIQS-TDNGGYYIS----GGVKFSSLAEL 73

                  ....
gi 31982209   427 VNSH 430
Cdd:pfam00017  74 VEHY 77

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 346 PWYAGACDRKSAEEALhRSNKDGSFLIRKSSghDSKQPYTL-VAFFNKRVYNIPVRFIEATKQYALGKKKngeeYFGSVV 424
Cdd:cd00173   1 PWFHGSISREEAERLL-RGKPDGTFLVRESS--SEPGDYVLsVRSGDGKVKHYLIERNEGGYYLLGGSGR----TFPSLP 73

                ....*.
gi 31982209 425 EIVNSH 430
Cdd:cd00173  74 ELVEHY 79

Src homology 2 (SH2) domain found in the Vav family; Vav proteins are involved in several processes that require cytoskeletal reorganization, such as the formation of the immunological synapse (IS), phagocytosis, platelet aggregation, spreading, and transformation. Vavs function as guanine nucleotide exchange factors (GEFs) for the Rho/Rac family of GTPases. Vav family members have several conserved motifs/domains including: a leucine-rich region, a leucine-zipper, a calponin homology (CH) domain, an acidic domain, a Dbl-homology (DH) domain, a pleckstrin homology (PH) domain, a cysteine-rich domain, 2 SH3 domains, a proline-rich region, and a SH2 domain. Vavs are the only known Rho GEFs that have both the DH/PH motifs and SH2/SH3 domains in the same protein. The leucine-rich helix-loop-helix (HLH) domain is thought to be involved in protein heterodimerization with other HLH proteins and it may function as a negative regulator by forming inactive heterodimers. The CH domain is usually involved in the association with filamentous actin, but in Vav it controls NFAT stimulation, Ca2+ mobilization, and its transforming activity. Acidic domains are involved in protein-protein interactions and contain regulatory tyrosines. The DH domain is a GDP-GTP exchange factor on Rho/Rac GTPases. The PH domain in involved in interactions with GTP-binding proteins, lipids and/or phosphorylated serine/threonine residues. The SH3 domain is involved in localization of proteins to specific sites within the cell interacting with protein with proline-rich sequences. The SH2 domain mediates a high affinity interaction with tyrosine phosphorylated proteins. There are three Vav mammalian family members: Vav1 which is expressed in the hematopoietic system, Vav2 and Vav3 are more ubiquitously expressed. The members here include insect and amphibian Vavs. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 341 ELLGKPWYAGACDRKSAEEALhRSNKDGSFLIRKSSGHDSKqpYTLVAFFNKRVYNIPVrFIEATKQYALGKKKngeeYF 420
Cdd:cd09940   1 DLSEFLWFVGEMERDTAENRL-ENRPDGTYLVRVRPQGETQ--YALSIKYNGDVKHMKI-EQRSDGLYYLSESR----HF 72

                        90       100       110
                ....*....|....*....|....*....|..
gi 31982209 421 GSVVEIVNSHQHNPLvlidSQNNTKDSTRLKY 452
Cdd:cd09940  73 KSLVELVNYYERNSL----GENFAGLDTTLKW 100

Src homology 2 (SH2) domain found in Tec protein, Txk; A member of the Tec protein tyrosine kinase Txk is expressed in thymus, spleen, lymph node, T lymphocytes, NK cells, mast cell lines, and myeloid cell line. Txk plays a role in TCR signal transduction, T cell development, and selection which is analogous to the function of Itk. Txk has been shown to interact with IFN-gamma. Unlike most of the Tec family members Txk lacks a PH domain. Instead Txk has a unique region containing a palmitoylated cysteine string which has a similar membrane tethering function as the PH domain. Txk also has a zinc-binding motif, a SH3 domain, a SH2 domain, and a protein kinase catalytic domain. The TH domain consists of a Zn2+-binding Btk motif and a proline-rich region. The Btk motif is found in Tec kinases, Ras GAP, and IGBP and crucial to the function of the PH domain. It is not present in Txk which is not surprising since it lacks a PH domain. The type 1 splice form of the Drosophila homolog also lacks both the PH domain and the Btk motif. The proline-rich regions are highly conserved for the most part with the exception of Bmx whose residues surrounding the PXXP motif are not conserved (TH-like) and Btk29A which is entirely unique with large numbers of glycine residues (TH-extended). Tec family members all lack a C-terminal tyrosine having an autoinhibitory function in its phosphorylated state. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 347 WYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSkqpYTLVAFFNKRvynipvRFIEAT-KQYALGKKKNGEEY------ 419
Cdd:cd10398   8 WYHKNITRNQAERLLRQESKEGAFIVRDSRHLGS---YTISVFTRAR------RSTEASiKHYQIKKNDSGQWYvaerhl 78

                        90       100       110
                ....*....|....*....|....*....|....*
gi 31982209 420 FGSVVEIVNSHQHNPLVLIdsqnntkdsTRLKYAV 454
Cdd:cd10398  79 FQSIPELIQYHQHNAAGLM---------SRLRYPV 104

Src homology 2 (SH2) domain found in feline sarcoma, Fujinami poultry sarcoma, and fes-related (Fes/Fps/Fer) proteins; The Fps family consists of members Fps/Fes and Fer/Flk/Tyk3. They are cytoplasmic protein-tyrosine kinases implicated in signaling downstream from cytokines, growth factors and immune receptors. Fes/Fps/Fer contains three coiled-coil regions, an SH2 (Src-homology-2) and a TK (tyrosine kinase catalytic) domain signature. Members here include: Fps/Fes, Fer, Kin-31, and In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 341 ELLGKPWYAGACDRKSAEEALHrsnKDGSFLIRKSSGH-DSKQPYTLVAFFNKRVYNIPVRFiEATKQYALGKKKngeey 419
Cdd:cd10361   2 DLENEPYYHGLLPREDAEELLK---NDGDFLVRKTEPKgGGKRKLVLSVRWDGKIRHFVINR-DDGGKYYIEGKS----- 72

                        90
                ....*....|....
gi 31982209 420 FGSVVEIVNSHQHN 433
Cdd:cd10361  73 FKSISELINYYQKT 86

C-terminal Src homology 2 (cSH2) domain found in p85; Phosphoinositide 3-kinases (PI3Ks) are essential for cell growth, migration, and survival. p110, the catalytic subunit, is composed of an adaptor-binding domain, a Ras-binding domain, a C2 domain, a helical domain, and a kinase domain. The regulatory unit is called p85 and is composed of an SH3 domain, a RhoGap domain, a N-terminal SH2 (nSH2) domain, a inter SH2 (iSH2) domain, and C-terminal (cSH2) domain. There are 2 inhibitory interactions between p110alpha and p85 of P13K: 1) p85 nSH2 domain with the C2, helical, and kinase domains of p110alpha and 2) p85 iSH2 domain with C2 domain of p110alpha. There are 3 inhibitory interactions between p110beta and p85 of P13K: 1) p85 nSH2 domain with the C2, helical, and kinase domains of p110beta, 2) p85 iSH2 domain with C2 domain of p110alpha, and 3) p85 cSH2 domain with the kinase domain of p110alpha. It is interesting to note that p110beta is oncogenic as a wild type protein while p110alpha lacks this ability. One explanation is the idea that the regulation of p110beta by p85 is unique because of the addition of inhibitory contacts from the cSH2 domain and the loss of contacts in the iSH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 345 KPWYAGACDRKSAEEALhRSNKDGSFLIRKSSGHDskqPYTLVAFFNKRVYNIPVRFIEATKQYAlgkkkngEEY--FGS 422
Cdd:cd09930   6 RTWLVGDINRTQAEELL-RGKPDGTFLIRESSTQG---CYACSVVCNGEVKHCVIYKTETGYGFA-------EPYnlYES 74

                        90       100       110
                ....*....|....*....|....*....|..
gi 31982209 423 VVEIVNSHQHNPLVlidsQNNTKDSTRLKYAV 454
Cdd:cd09930  75 LKELVLHYAHNSLE----QHNDSLTVTLAYPV 102

Src homology 2 (SH2) domain found in alpha2-chimerin and beta2-chimerin proteins; Chimerins are a family of phorbol ester- and diacylglycerol-responsive GTPase-activating proteins. Alpha1-chimerin (formerly known as n-chimerin) and alpha2-chimerin are alternatively spliced products of a single gene, as are beta1- and beta2-chimerin. alpha1- and beta1-chimerin have a relatively short N-terminal region that does not encode any recognizable domains, whereas alpha2- and beta2-chimerin both include a functional SH2 domain that can bind to phosphotyrosine motifs within receptors. All of the isoforms contain a GAP domain with specificity in vitro for Rac1 and a diacylglycerol (DAG)-binding C1 domain which allows them to translocate to membranes in response to DAG signaling and anchors them in close proximity to activated Rac. Other C1 domain-containing diacylglycerol receptors including: PKC, Munc-13 proteins, phorbol ester binding scaffolding proteins involved in Ca2+-stimulated exocytosis, and RasGRPs, diacylglycerol-activated guanine-nucleotide exchange factors (GEFs) for Ras and Rap1. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 348 YAGACDRKSAEEALhRSNKDGSFLIRKSSGHDSKqpYTLVAFFNKRVYNIPVRFIEATKQYALGKKKngeeyFGSVVEIV 427
Cdd:cd10352   9 YHGLISREEAEQLL-SGASDGSYLIRESSRDDGY--YTLSLRFNGKVKNYKLYYDGKNHYHYVGEKR-----FDTIHDLV 80

Src homology 2 (SH2) domain found in SH2-containing inositol-5'-phosphatase (SHIP) and SLAM-associated protein (SAP); The SH2-containing inositol-5'-phosphatase, SHIP (also called SHIP1/SHIP1a), is a hematopoietic-restricted phosphatidylinositide phosphatase that translocates to the plasma membrane after extracellular stimulation and hydrolyzes the phosphatidylinositol-3-kinase (PI3K)-generated second messenger PI-3,4,5-P3 (PIP3) to PI-3,4-P2. As a result, SHIP dampens down PIP3 mediated signaling and represses the proliferation, differentiation, survival, activation, and migration of hematopoietic cells. PIP3 recruits lipid-binding pleckstrin homology(PH) domain-containing proteins to the inner wall of the plasma membrane and activates them. PH domain-containing downstream effectors include the survival/proliferation enhancing serine/threonine kinase, Akt (protein kinase B), the tyrosine kinase, Btk, the regulator of protein translation, S6K, and the Rac and cdc42 guanine nucleotide exchange factor, Vav. SHIP is believed to act as a tumor suppressor during leukemogenesis and lymphomagenesis, and may play a role in activating the immune system to combat cancer. SHIP contains an N-terminal SH2 domain, a centrally located phosphatase domain that specifically hydrolyzes the 5'-phosphate from PIP3, PI-4,5-P2 and inositol-1,3,4,5- tetrakisphosphate (IP4), a C2 domain, that is an allosteric activating site when bound by SHIP's enzymatic product, PI-3,4-P2; 2 NPXY motifs that bind proteins with a phosphotyrosine binding (Shc, Dok 1, Dok 2) or an SH2 (p85a, SHIP2) domain; and a proline-rich domain consisting of four PxxP motifs that bind a subset of SH3-containing proteins including Grb2, Src, Lyn, Hck, Abl, PLCg1, and PIAS1. The SH2 domain of SHIP binds to the tyrosine phosphorylated forms of Shc, SHP-2, Doks, Gabs, CD150, platelet-endothelial cell adhesion molecule, Cas, c-Cbl, immunoreceptor tyrosine-based inhibitory motifs (ITIMs), and immunoreceptor tyrosine-based activation motifs (ITAMs). The X-linked lymphoproliferative syndrome (XLP) gene encodes SAP (also called SH2D1A/DSHP) a protein that consists of a 5 residue N-terminus, a single SH2 domain, and a short 25 residue C-terminal tail. XLP is characterized by an extreme sensitivity to Epstein-Barr virus. Both T and natural killer (NK) cell dysfunctions have been seen in XLP patients. SAP binds the cytoplasmic tail of Signaling lymphocytic activation molecule (SLAM), 2B4, Ly-9, and CD84. SAP is believed to function as a signaling inhibitor, by blocking or regulating binding of other signaling proteins. SAP and the SAP-like protein EAT-2 recognize the sequence motif TIpYXX(V/I), which is found in the cytoplasmic domains of a restricted number of T, B, and NK cell surface receptors and are proposed to be natural inhibitors or regulators of the physiological role of a small family of receptors on the surface of these cells. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 31982209 344 GKPWYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSKqpYTLVAFFNKRVY 395
Cdd:cd10343   2 APPWYHGNITRSKAEELLSKAGKDGSFLVRDSESVSGA--YALCVLYQNCVH 51

large tegument protein UL36; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209    99 PPAEQQTRVVHPALPFT-------RGEYVDNRSSQRHSPPFSKTLPSK--PSWPSAKARLASTLPAPNSLQKP-QVPPKP 168
Cdd:PHA03247 2722 PPGPAAARQASPALPAApappavpAGPATPGGPARPARPPTTAGPPAPapPAAPAAGPPRRLTRPAVASLSESrESLPSP 2801

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209   169 KDLlEDEADYVVPVEDNDENYIHPRESSPPPAEKAPmVNRSTKPNSSSKHMSPPGTVAgrnSGVWDSKSSLPAAPSPLPR 248
Cdd:PHA03247 2802 WDP-ADPPAAVLAPAAALPPAASPAGPLPPPTSAQP-TAPPPPPGPPPPSLPLGGSVA---PGGDVRRRPPSRSPAAKPA 2876

                         170       180       190       200       210       220       230
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 31982209   249 AGKKPatPLKTTPVPPLPNASNVCEEKPVPAERHRgsshrqdTVQSPVFPPTQKPVHQKPVPLPRFPEAGSPAA 322
Cdd:PHA03247 2877 APARP--PVRRLARPAVSRSTESFALPPDQPERPP-------QPQAPPPPQPQPQPPPPPQPQPPPPPPPRPQP 2941

Src homology 2 (SH2) domain found in Nck; Nck proteins are adaptors that modulate actin cytoskeleton dynamics by linking proline-rich effector molecules to tyrosine kinases or phosphorylated signaling intermediates. There are two members known in this family: Nck1 (Nckalpha) and Nck2 (Nckbeta and Growth factor receptor-bound protein 4 (Grb4)). They are characterized by having 3 SH3 domains and a C-terminal SH2 domain. Nck1 and Nck2 have overlapping functions as determined by gene knockouts. Both bind receptor tyrosine kinases and other tyrosine-phosphorylated proteins through their SH2 domains. In addition they also bind distinct targets. Neuronal signaling proteins: EphrinB1, EphrinB2, and Disabled-1 (Dab-1) all bind to Nck-2 exclusively. And in the case of PDGFR, Tyr(P)751 binds to Nck1 while Tyr(P)1009 binds to Nck2. Nck1 and Nck2 have a role in the infection process of enteropathogenic Escherichia coli (EPEC). Their SH3 domains are involved in recruiting and activating the N-WASP/Arp2/3 complex inducing actin polymerization resulting in the production of pedestals, dynamic bacteria-presenting protrusions of the plasma membrane. A similar thing occurs in the vaccinia virus where motile plasma membrane projections are formed beneath the virus. Recently it has been shown that the SH2 domains of both Nck1 and Nck2 bind the G-protein coupled receptor kinase-interacting protein 1 (GIT1) in a phosphorylation-dependent manner. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 345 KPWYAGACDRKSAEEALHRSNKDGSFLIRKSSGHDSKQPYTLVAFFNKRVYNIPVRfieaTKQYALGKKKngeeyFGSVV 424
Cdd:cd10408   1 NPWYYGKVTRHQAEMALNERGNEGDFLIRDSESSPNDFSVSLKAQGKNKHFKVQLK----ECVYCIGQRK-----FSSME 71

                        90
                ....*....|.
gi 31982209 425 EIVNSHQHNPL 435
Cdd:cd10408  72 ELVEHYKKAPI 82

Src homology 2 (SH2) domain found in the Nck family; Nck proteins are adaptors that modulate actin cytoskeleton dynamics by linking proline-rich effector molecules to tyrosine kinases or phosphorylated signaling intermediates. There are two members known in this family: Nck1 (Nckalpha) and Nck2 (Nckbeta and Growth factor receptor-bound protein 4 (Grb4)). They are characterized by having 3 SH3 domains and a C-terminal SH2 domain. Nck1 and Nck2 have overlapping functions as determined by gene knockouts. Both bind receptor tyrosine kinases and other tyrosine-phosphorylated proteins through their SH2 domains. In addition they also bind distinct targets. Neuronal signaling proteins: EphrinB1, EphrinB2, and Disabled-1 (Dab-1) all bind to Nck-2 exclusively. And in the case of PDGFR, Tyr(P)751 binds to Nck1 while Tyr(P)1009 binds to Nck2. Nck1 and Nck2 have a role in the infection process of enteropathogenic Escherichia coli (EPEC). Their SH3 domains are involved in recruiting and activating the N-WASP/Arp2/3 complex inducing actin polymerization resulting in the production of pedestals, dynamic bacteria-presenting protrusions of the plasma membrane. A similar thing occurs in the vaccinia virus where motile plasma membrane projections are formed beneath the virus. Recently it has been shown that the SH2 domains of both Nck1 and Nck2 bind the G-protein coupled receptor kinase-interacting protein 1 (GIT1) in a phosphorylation-dependent manner. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 345 KPWYAGACDRKSAEEALHRSNKDGSFLIRKSSGhdskqpytlvaffNKRVYNIPVRFIEATKQYALGKKKN----GEEYF 420
Cdd:cd09943   1 QPWYYGRITRHQAETLLNEHGHEGDFLIRDSES-------------NPGDYSVSLKAPGRNKHFKVQVVDNvyciGQRKF 67

                        90
                ....*....|....*
gi 31982209 421 GSVVEIVNSHQHNPL 435
Cdd:cd09943  68 HTMDELVEHYKKAPI 82

Src homology 2 (SH2) domain found in SH2 adaptor protein C (SHC); SHC is involved in a wide variety of pathways including regulating proliferation, angiogenesis, invasion and metastasis, and bone metabolism. An adapter protein, SHC has been implicated in Ras activation following the stimulation of a number of different receptors, including growth factors [insulin, epidermal growth factor (EGF), nerve growth factor, and platelet derived growth factor (PDGF)], cytokines [interleukins 2, 3, and 5], erythropoietin, and granulocyte/macrophage colony-stimulating factor, and antigens [T-cell and B-cell receptors]. SHC has been shown to bind to tyrosine-phosphorylated receptors, and receptor stimulation leads to tyrosine phosphorylation of SHC. Upon phosphorylation, SHC interacts with another adapter protein, Grb2, which binds to the Ras GTP/GDP exchange factor mSOS which leads to Ras activation. SHC is composed of an N-terminal domain that interacts with proteins containing phosphorylated tyrosines, a (glycine/proline)-rich collagen-homology domain that contains the phosphorylated binding site, and a C-terminal SH2 domain. SH2 has been shown to interact with the tyrosine-phosphorylated receptors of EGF and PDGF and with the tyrosine-phosphorylated C chain of the T-cell receptor, providing one of the mechanisms of T-cell-mediated Ras activation. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 339 EAELLGKPWYAGACDRKSAEEALHRsnkDGSFLIRKS---------SGHDSKQPYTLVAFFNKRVynipVRfieaTKQYA 409
Cdd:cd09925   1 AEQLRGEPWYHGKMSRRDAESLLQT---DGDFLVREStttpgqyvlTGMQNGQPKHLLLVDPEGV----VR----TKDRV 69

                        90       100
                ....*....|....*....|....*....
gi 31982209 410 lgkkkngeeyFGSVVEIVNSHQHNPLVLI 438
Cdd:cd09925  70 ----------FESISHLINYHVTNGLPII 88

C-terminal Src homology 2 (C-SH2) domain found in SH2 domain Phosphatases (SHP) proteins; The SH2 domain phosphatases (SHP-1, SHP-2/Syp, Drosophila corkscrew (csw), and Caenorhabditis elegans Protein Tyrosine Phosphatase (Ptp-2)) are cytoplasmic signaling enzymes. They are both targeted and regulated by interactions of their SH2 domains with phosphotyrosine docking sites. These proteins contain two SH2 domains (N-SH2, C-SH2) followed by a tyrosine phosphatase (PTP) domain, and a C-terminal extension. Shp1 and Shp2 have two tyrosyl phosphorylation sites in their C-tails, which are phosphorylated differentially by receptor and nonreceptor PTKs. Csw retains the proximal tyrosine and Ptp-2 lacks both sites. Shp-binding proteins include receptors, scaffolding adapters, and inhibitory receptors. Some of these bind both Shp1 and Shp2 while others bind only one. Most proteins that bind a Shp SH2 domain contain one or more immuno-receptor tyrosine-based inhibitory motifs (ITIMs): [SIVL]xpYxx[IVL]. Shp1 N-SH2 domain blocks the catalytic domain and keeps the enzyme in the inactive conformation, and is thus believed to regulate the phosphatase activity of SHP-1. Its C-SH2 domain is thought to be involved in searching for phosphotyrosine activators. The SHP2 N-SH2 domain is a conformational switch; it either binds and inhibits the phosphatase, or it binds phosphoproteins and activates the enzyme. The C-SH2 domain contributes binding energy and specificity, but it does not have a direct role in activation. Csw SH2 domain function is essential, but either SH2 domain can fulfill this requirement. The role of the csw SH2 domains during Sevenless receptor tyrosine kinase (SEV) signaling is to bind Daughter of Sevenless rather than activated SEV. Ptp-2 acts in oocytes downstream of sheath/oocyte gap junctions to promote major sperm protein (MSP)-induced MAP Kinase (MPK-1) phosphorylation. Ptp-2 functions in the oocyte cytoplasm, not at the cell surface to inhibit multiple RasGAPs, resulting in sustained Ras activation. It is thought that MSP triggers PTP-2/Ras activation and ROS production to stimulate MPK-1 activity essential for oocyte maturation and that secreted MSP domains and Cu/Zn superoxide dismutases function antagonistically to control ROS and MAPK signaling. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 347 WYAGACDRKSAEEALHRSNKDGSFLIRKSsghdSKQP--YTL-VAFFNKRVYNIPVRFIEatKQYALGkkknGEEYFGSV 423
Cdd:cd09931   2 WFHGHLSGKEAEKLLLEKGKPGSFLVRES----QSKPgdFVLsVRTDDDKVTHIMIRCQG--GKYDVG----GGEEFDSL 71

                        90
                ....*....|...
gi 31982209 424 VEIVNSHQHNPLV 436
Cdd:cd09931  72 TDLVEHYKKNPMV 84

C-terminal Src homology 2 (SH2) domain found in SH2 domains, ANK, and kinase domain (shark) proteins; These non-receptor protein-tyrosine kinases contain two SH2 domains, five ankyrin (ANK)-like repeats, and a potential tyrosine phosphorylation site in its carboxyl-terminal tail which resembles the phosphorylation site in members of the src family. Like, mammalian non-receptor protein-tyrosine kinases, ZAP-70 and syk proteins, they do not have SH3 domains. However, the presence of ANK makes these unique among protein-tyrosine kinases. Both tyrosine kinases and ANK repeats have been shown to transduce developmental signals, and SH2 domains are known to participate intimately in tyrosine kinase signaling. These tyrosine kinases are believed to be involved in epithelial cell polarity. The members of this family include the shark (SH2 domains, ANK, and kinase domain) gene in Drosophila and yellow fever mosquitos, as well as the hydra protein HTK16. Drosophila Shark is proposed to transduce intracellularly the Crumbs, a protein necessary for proper organization of ectodermal epithelia, intercellular signal. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 31982209 347 WYAGACDRKSAEEAL-HRSNKDGSFLIRKSSGHDSKQPYTLVafFNKRVYNIPVR 400
Cdd:cd10348   2 WLHGALDRNEAVEILkQKADADGSFLVRYSRRRPGGYVLTLV--YENHVYHFEIQ 54

large tegument protein UL36; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209   127 RHSPPFSKTLPSKPSWPSAKARLASTLPAPnslqKPQVPPKPKDLLEDEAD------YVVPVEdndenyiHPRESSPP-- 198
Cdd:PHA03247  283 EAAAPNGAAAPPDGVWGAALAGAPLALPAP----PDPPPPAPAGDAEEEDDedgameVVSPLP-------RPRQHYPLgf 351

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209   199 PAEKAPmvnrSTKPNSSSKHMSPPGTVAGRNSGVWDSKSSLPAAPSPLPRAGKKPATPLKTTPVP---PLPNASNVCEEK 275
Cdd:PHA03247  352 PKRRRP----TWTPPSSLEDLSAGRHHPKRASLPTRKRRSARHAATPFARGPGGDDQTRPAAPVPasvPTPAPTPVPASA 427

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209   276 PVPAERHRGSSHRQDTVQSPVFPPTQKPVHQKPVPLPRFPEAGSPAADGPFHSFPFNSTFADQeAELLGK-PWYAGACDR 354
Cdd:PHA03247  428 PPPPATPLPSAEPGSDDGPAPPPERQPPAPATEPAPDDPDDATRKALDALRERRPPEPPGADL-AELLGRhPDTAGTVVR 506

                  ....*.
gi 31982209   355 KSAEEA 360
Cdd:PHA03247  507 LAAREA 512

N-terminal Src homology 2 (SH2) domain found in Ras GTPase-activating protein 1 (GAP); RasGAP is part of the GAP1 family of GTPase-activating proteins. The protein is located in the cytoplasm and stimulates the GTPase activity of normal RAS p21, but not its oncogenic counterpart. Acting as a suppressor of RAS function, the protein enhances the weak intrinsic GTPase activity of RAS proteins resulting in RAS inactivation, thereby allowing control of cellular proliferation and differentiation. Mutations leading to changes in the binding sites of either protein are associated with basal cell carcinomas. Alternative splicing results in two isoforms. The shorter isoform which lacks the N-terminal hydrophobic region, has the same activity, and is expressed in placental tissues. In general the longer isoform contains 2 SH2 domains, a SH3 domain, a pleckstrin homology (PH) domain, and a calcium-dependent phospholipid-binding C2 domain. The C-terminus contains the catalytic domain of RasGap which catalyzes the activation of Ras by hydrolyzing GTP-bound active Ras into an inactive GDP-bound form of Ras. This model contains the N-terminal SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20
                ....*....|....*....|....*....
gi 31982209 347 WYAGACDRKSAEEALHRSNKDGSFLIRKS 375
Cdd:cd10353  21 WYHGRLDRTIAEERLRQAGKLGSYLIRES 49

Src homology 2 (SH2) domain found in SH2 domain-bearing protein kinases D and E (ShkD and ShkE); SH2-bearing genes cloned from Dictyostelium include two transcription factors, STATa and STATc, and a signaling factor, SHK1 (shkA). A database search of the Dictyostelium discoideum genome revealed two additional putative STAT sequences, dd-STATb and dd-STATd, and four additional putative SHK genes, dd-SHK2 (shkB), dd-SHK3 (shkC), dd-SHK4 (shkD), and dd-SHK5 (shkE). This model contains members of shkD and shkE. All of the SHK members are most closely related to the protein kinases found in plants. However these kinases in plants are not conjugated to any SH2 or SH2-like sequences. Alignment data indicates that the SHK SH2 domains carry some features of the STAT SH2 domains in Dictyostelium. When STATc's linker domain was used for a BLAST search, the sequence between the protein kinase domain and the SH2 domain (the linker) of SHK was recovered, suggesting a close relationship among these molecules within this region. SHK's linker domain is predicted to contain an alpha-helix which is indeed homologous to that of STAT. Based on the phylogenetic alignment, SH2 domains can be grouped into two categories, STAT-type and Src-type. SHK family members are in between, but are closer to the STAT-type which indicates a close relationship between SHK and STAT families in their SH2 domains and further supports the notion that SHKs linker-SH2 domain evolved from STAT or STATL (STAT-like Linker-SH2) domain found in plants. In SHK, STAT, and SPT6, the linker-SH2 domains all reside exclusively in the C-terminal regions. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 337 DQEAELLGKPWYAGACDRKSAEEALhRSNKDGSFLIRKSSGHDSKQPYTLVAFFN-----KRVYNIPVRFIEaTKQYALG 411
Cdd:cd10357   2 MNINILLAKSWFHGDISRDEAEKRL-RGRPEGTFLIRLSSTDPKKTPFTISKKKKskpvhKRISRIDVNNYT-SFKIPGG 79

                ...
gi 31982209 412 KKK 414
Cdd:cd10357  80 YAV 82

Src homology 2 (SH2) domain found in Carboxyl-Terminal Src Kinase (Csk); Both the C-terminal Src kinase (CSK) and CSK-homologous kinase (CHK) are members of the CSK-family of protein tyrosine kinases. These proteins suppress activity of Src-family kinases (SFK) by selectively phosphorylating the conserved C-terminal tail regulatory tyrosine by a similar mechanism. CHK is also capable of inhibiting SFKs by a non-catalytic mechanism that involves binding of CHK to SFKs to form stable protein complexes. The unphosphorylated form of SFKs is inhibited by CSK and CHK by a two-step mechanism. The first step involves the formation of a complex of SFKs with CSK/CHK with the SFKs in the complex are inactive. The second step, involves the phosphorylation of the C-terminal tail tyrosine of SFKs, which then dissociates and adopt an inactive conformation. The structural basis of how the phosphorylated SFKs dissociate from CSK/CHK to adopt the inactive conformation is not known. The inactive conformation of SFKs is stabilized by two intramolecular inhibitory interactions: (a) the pYT:SH2 interaction in which the phosphorylated C-terminal tail tyrosine (YT) binds to the SH2 domain, and (b) the linker:SH3 interaction of which the SH2-kinase domain linker binds to the SH3 domain. SFKs are activated by multiple mechanisms including binding of the ligands to the SH2 and SH3 domains to displace the two inhibitory intramolecular interactions, autophosphorylation, and dephosphorylation of YT. By selective phosphorylation and the non-catalytic inhibitory mechanism CSK and CHK are able to inhibit the active forms of SFKs. CSK and CHK are regulated by phosphorylation and inter-domain interactions. They both contain SH3, SH2, and kinase domains separated by the SH3-SH2 connector and SH2 kinase linker, intervening segments separating the three domains. They lack a conserved tyrosine phosphorylation site in the kinase domain and the C-terminal tail regulatory tyrosine phosphorylation site. The CSK SH2 domain is crucial for stabilizing the kinase domain in the active conformation. A disulfide bond here regulates CSK kinase activity. The subcellular localization and activity of CSK are regulated by its SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 31982209 346 PWYAGACDRKSAEEALhRSNKDGSFLIRKSSGHdskqP--YTLVAFFNKRVYNIPVRFIEatkqyalGKKK-NGEEYFGS 422
Cdd:cd09937   4 PWFHGKISREEAERLL-QPPEDGLFLVRESTNY----PgdYTLCVSFEGKVEHYRVIYRN-------GKLTiDEEEYFEN 71

                ....*
gi 31982209 423 VVEIV 427
Cdd:cd09937  72 LIQLV 76

Src homology 2 domain found in SH2 domain-containing adapter proteins B, D, E, and F (SHB, SHD, SHE, SHF); SHB, SHD, SHE, and SHF are SH2 domain-containing proteins that play various roles throughout the cell. SHB functions in generating signaling compounds in response to tyrosine kinase activation. SHB contains proline-rich motifs, a phosphotyrosine binding (PTB) domain, tyrosine phosphorylation sites, and a SH2 domain. SHB mediates certain aspects of platelet-derived growth factor (PDGF) receptor-, fibroblast growth factor (FGF) receptor-, neural growth factor (NGF) receptor TRKA-, T cell receptor-, interleukin-2 (IL-2) receptor- and focal adhesion kinase- (FAK) signaling. SRC-like FYN-Related Kinase FRK/RAK (also named BSK/IYK or GTK) and SHB regulate apoptosis, proliferation and differentiation. SHB promotes apoptosis and is also required for proper mitogenicity, spreading and tubular morphogenesis in endothelial cells. SHB also plays a role in preventing early cavitation of embryoid bodies and reduces differentiation to cells expressing albumin, amylase, insulin and glucagon. SHB is a multifunctional protein that has difference responses in different cells under various conditions. SHE is expressed in heart, lung, brain, and skeletal muscle, while expression of SHD is restricted to the brain. SHF is mainly expressed in skeletal muscle, brain, liver, prostate, testis, ovary, small intestine, and colon. SHD may be a physiological substrate of c-Abl and may function as an adapter protein in the central nervous system. It is also thought to be involved in apoptotic regulation. SHD contains five YXXP motifs, a substrate sequence preferred by Abl tyrosine kinases, in addition to a poly-proline rich region and a C-terminal SH2 domain. SHE contains two pTry protein binding domains, protein interaction domain (PID) and a SH2 domain, followed by a glycine-proline rich region, all of which are N-terminal to the phosphotyrosine binding (PTB) domain. SHF contains four putative tyrosine phosphorylation sites and an SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|..
gi 31982209 345 KPWYAGACDRKSAEEALhRSNKDGSFLIRKSsgHDSKQPYTL 386
Cdd:cd09945   1 QGWYHGAITRIEAESLL-RPCKEGSYLVRNS--ESTKQDYSL 39