calponin homology (CH) domain superfamily; CH domains are actin filament (F-actin) binding motifs, which may be present as a single copy or in tandem repeats (which increase binding affinity). They either function as autonomous actin binding motifs or serve a regulatory function. CH domains are found in cytoskeletal and signal transduction proteins, including actin-binding proteins like spectrin, alpha-actinin, dystrophin, utrophin, and fimbrin, as well as proteins essential for regulation of cell shape (cortexillins), and signaling proteins (Vav).

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506520  23 KYDHQAEEDLRNWIEEVTGMSIGPNFQLGLKDGIILCELINKLQPGSVKKVNESSLNWPQAKTKG 87
Cdd:cd21284    1 KYDPQKEEELRNWIEEVTGMSIGENFQKGLKDGVILCELINKLQPGSIRKINESKLNWHQLENIG 65

Calponin family repeat;

                          10        20
                  ....*....|....*....|....*
gi 554506520  197 ISLQMGTNKVASQKGMSVYGLGRQV 221
Cdd:pfam00402   1 IGLQMGTNKGASQSGMTAFGAVRHI 25

calponin homology (CH) domain found in calponin-3; Calponin-3 (CNN3), also called acidic isoform calponin, is an F-actin-binding protein that is expressed in the brain and has been shown to control dendritic spine morphology, density, and plasticity by regulating actin cytoskeletal reorganization and dynamics. It contains a single copy of the CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506520  23 KYDHQAEEDLRNWIEEVTGMSIGPNFQLGLKDGIILCELINKLQPGSVKKVNESSLNWPQAKTKG 87
Cdd:cd21284    1 KYDPQKEEELRNWIEEVTGMSIGENFQKGLKDGVILCELINKLQPGSIRKINESKLNWHQLENIG 65

Calponin homology domain; Actin binding domains present in duplicate at the N-termini of spectrin-like proteins (including dystrophin, alpha-actinin). These domains cross-link actin filaments into bundles and networks. A calponin homology domain is predicted in yeasst Cdc24p.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 554506520    30 EDLRNWIEEVTGMSIGP---NFQLGLKDGIILCELINKLQPGSVKKVNESSLNWPQAKTK 86
Cdd:smart00033   1 KTLLRWVNSLLAEYDKPpvtNFSSDLKDGVALCALLNSLSPGLVDKKKVAASLSRFKKIE 60

Calponin family repeat;

                          10        20
                  ....*....|....*....|....*
gi 554506520  197 ISLQMGTNKVASQKGMSVYGLGRQV 221
Cdd:pfam00402   1 IGLQMGTNKGASQSGMTAFGAVRHI 25

Calponin [Cytoskeleton];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 554506520  16 VKNKIASKYDHQAEEDLRNWIEEVTGMSIGPNFQL--GLKDGIILCELINKLQPGSVkKVNESSLNWPQAKtkgfhtTID 93
Cdd:COG5199    2 VNTKNRCPGMDKQQKEVTLWIETVLGEKFEPPGDLlsLLKDGVRLCRILNEASPLDI-KYKESKMPFVQME------NIS 74

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 554506520  94 IGVKYAEK---------QTRRFDEGKLKAgQSVIGLQmgtnkcasqaGMTAYGTRRHLYD-----PKMQTDKP------- 152
Cdd:COG5199   75 SFINGLKKlrvpeyelfQTNDLFEAKDLR-QVVICLY----------SLSRYAQKERMFSgpflgPHLATKKPrvfssqe 143

                        170       180       190
                 ....*....|....*....|....*....|....
gi 554506520 153 ---FDQTTISLQMGTNKGASQAG-MLAPGTRRDI 182
Cdd:COG5199  144 vldRSKGAIHLQYGYSDLSEQSTeKGASNVRRDL 177

calponin homology (CH) domain found in calponin-3; Calponin-3 (CNN3), also called acidic isoform calponin, is an F-actin-binding protein that is expressed in the brain and has been shown to control dendritic spine morphology, density, and plasticity by regulating actin cytoskeletal reorganization and dynamics. It contains a single copy of the CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 554506520  23 KYDHQAEEDLRNWIEEVTGMSIGPNFQLGLKDGIILCELINKLQPGSVKKVNESSLNWPQAKTKG 87
Cdd:cd21284    1 KYDPQKEEELRNWIEEVTGMSIGENFQKGLKDGVILCELINKLQPGSIRKINESKLNWHQLENIG 65

calponin homology (CH) domain found in calponin-2; Calponin-2 (CNN2), also called neutral calponin, or smooth muscle calponin H2, is an actin cytoskeleton-associated regulatory protein that inhibits the activity of myosin-ATPase and cytoskeleton dynamics. It contains a single copy of the CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 554506520  25 DHQAEEDLRNWIEEVTGMSIGPNFQLGLKDGIILCELINKLQPGSVKKVNESSLNWPQ 82
Cdd:cd21283    1 DPQKEAELRTWIEGLTGRSIGPDFQKGLKDGVILCELMNKLQPGSVPKINRSMQNWHQ 58

calponin homology (CH) domain found in Drosophila melanogaster muscle-specific protein 20 (dMP20) and similar domains; This subfamily contains Drosophila melanogaster muscle-specific protein 20 (dMP20), Echinococcus granulosus myophilin, Dictyostelium discoideum Rac guanine nucleotide exchange factor B (also called Trix), and similar proteins. dMP20 is present only in the synchronous muscles of D. melanogaster. It may be involved in the system linking the nerve impulse with the contraction or the relaxation process. Trix is involved in the regulation of the late steps of the endocytic pathway. dMP20 contains a single copy of the CH domain, while Trix (triple CH-domain array exchange factor) contains three, two type 3 CH domains which are included in this model, and one type 1 CH domain that is not included in this subfamily, but is part of the superfamily. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 554506520  23 KYDHQAEEDLRNWIEEVTGMSI--GPNFQLGLKDGIILCELINKLQPGSVKKVNES 76
Cdd:cd21207    1 KRDPALEAEALDWIEAVTGEKLddGKDYEDVLKDGVILCKLINILKPGSVKKINTS 56

calponin homology (CH) domain superfamily; CH domains are actin filament (F-actin) binding motifs, which may be present as a single copy or in tandem repeats (which increase binding affinity). They either function as autonomous actin binding motifs or serve a regulatory function. CH domains are found in cytoskeletal and signal transduction proteins, including actin-binding proteins like spectrin, alpha-actinin, dystrophin, utrophin, and fimbrin, as well as proteins essential for regulation of cell shape (cortexillins), and signaling proteins (Vav).

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 554506520  29 EEDLRNWIEEVTGMSIGP---NFQLGLKDGIILCELINKLQPGSVKKVNESSLN 79
Cdd:cd00014    1 EEELLKWINEVLGEELPVsitDLFESLRDGVLLCKLINKLSPGSIPKINKKPKS 54

Calponin homology (CH) domain; The CH domain is found in both cytoskeletal proteins and signal transduction proteins. The CH domain is involved in actin binding in some members of the family. However in calponins there is evidence that the CH domain is not involved in its actin binding activity. Most member proteins have from two to four copies of the CH domain, however some proteins such as calponin have only a single copy.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 554506520   26 HQAEEDLRNWIEEVTGMSIGP----NFQLGLKDGIILCELINKLQPGSVKKVNESSLNWPQ 82
Cdd:pfam00307   1 LELEKELLRWINSHLAEYGPGvrvtNFTTDLRDGLALCALLNKLAPGLVDKKKLNKSEFDK 61

Calponin homology domain; Actin binding domains present in duplicate at the N-termini of spectrin-like proteins (including dystrophin, alpha-actinin). These domains cross-link actin filaments into bundles and networks. A calponin homology domain is predicted in yeasst Cdc24p.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 554506520    30 EDLRNWIEEVTGMSIGP---NFQLGLKDGIILCELINKLQPGSVKKVNESSLNWPQAKTK 86
Cdd:smart00033   1 KTLLRWVNSLLAEYDKPpvtNFSSDLKDGVALCALLNSLSPGLVDKKKVAASLSRFKKIE 60

calponin homology (CH) domain found in LIM and calponin homology domains-containing protein 1; LIM and calponin homology domains-containing protein 1 (LIMCH1) acts as an actin stress fiber-associated protein that activates the non-muscle myosin IIa complex by promoting the phosphorylation of its regulatory subunit MRLC/MYL9. It positively regulates actin stress fiber assembly and stabilizes focal adhesions, and therefore negatively regulates cell spreading and cell migration. LIMCH1 contains a single copy of the CH domain at the N-terminus. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 554506520  35 WIEEVTGMSIG-PNFQLGLKDGIILCELINKLQPGSVKKVN 74
Cdd:cd21278    8 WIEQVTGRSFGdKDFRSGLENGILLCELLNAIKPGLVKKIN 48

Calponin family repeat;

                          10        20
                  ....*....|....*....|....*
gi 554506520  197 ISLQMGTNKVASQKGMSVYGLGRQV 221
Cdd:pfam00402   1 IGLQMGTNKGASQSGMTAFGAVRHI 25

calponin homology (CH) domain found in transgelin-2; Transgelin-2, also called epididymis tissue protein Li 7e, or SM22-alpha homolog, acts as an actin-binding protein that induces actin gelation and regulates the actin cytoskeleton. It may participate in the development and progression of multiple cancers. It contains a single copy of the CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 554506520  20 IASKYDHQAEEDLRNWIEEVTGMSIGP------NFQLGLKDGIILCELINKLQPGS---VKKVNESSLNWPQ 82
Cdd:cd21280    1 IDKQYDADLEQILIQWITAQCGKQVGRpqpgreNFQNWLKDGTVLCHLINSLYPKGqapVKKIQASTMAFKQ 72

calponin homology (CH) domain found in the transgelin family; The transgelin (TAGLN) family includes transgelin, transgelin-2 and transgelin-3. Transgelin, also called 22 kDa actin-binding protein, protein WS3-10, or smooth muscle protein 22-alpha (SM22-alpha), acts as an actin cross-linking/gelling protein that may be involved in calcium interactions and in regulating contractile properties of the cell. Transgelin-2, also called epididymis tissue protein Li 7e, or SM22-alpha homolog, acts as an actin-binding protein that induces actin gelation and regulates actin cytoskeleton. It may participate in the development and progression of multiple cancers. Transgelin-3, also called neuronal protein 22 (NP22), or neuronal protein NP25, may have a role in alcohol-related adaptations and may mediate regulatory signal transduction pathways in neurons. Members of this family contain a single copy of the CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 554506520  25 DHQAEEDLRNWIEEVTGMSIGP------NFQLGLKDGIILCELINKLQP---GSVKKVNESSLNWPQ 82
Cdd:cd21209    1 DPELESRLVEWIVAQCGSDVGRpdpgrlGFQKWLKDGTVLCKLINSLYPegsKPVKKIQSSKMAFKQ 67

first calponin homology (CH) domain found in the plastin/fimbrin family; This family includes plastin and fimbrin. Plastin has three isoforms, plastin-1, -2, and -3, which are all actin-bundling proteins. Plastin-1, also called intestine-specific plastin, or I-plastin, is an actin-bundling protein in the absence of calcium. Plastin-2, also called L-plastin, LC64P, or lymphocyte cytosolic protein 1 (LCP-1), plays a role in the activation of T-cells in response to costimulation through TCR/CD3 and CD2 or CD28. It modulates the cell surface expression of IL2RA/CD25 and CD69. Plastin-3, also called T-plastin, is found in intestinal microvilli, hair cell stereocilia, and fibroblast filopodia. It may play a role in the regulation of bone development. Fimbrin has been found in plants and fungi. Arabidopsis thaliana fimbrin (AtFIM) includes fimbrin-1, -2, -3, -4, and -5; they cross-link actin filaments (F-actin) in a calcium independent manner. They stabilize and prevent F-actin depolymerization mediated by profilin. They act as key regulators of actin cytoarchitecture, probably involved in cell cycle, cell division, cell elongation and cytoplasmic tractus. AtFIM5 is an actin bundling factor that is required for pollen germination and pollen tube growth. Fungal fimbrin binds to actin, and functionally associates with actin structures involved in the development and maintenance of cell polarity. Members of this family contain four copies of the CH domain. This model corresponds to the first CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30
                 ....*....|....*....|....*....|....
gi 554506520  52 LKDGIILCELINKLQPGSvkkVNESSLNWPQAKT 85
Cdd:cd21217   37 LRDGVLLCKLINKIVPGT---IDERKLNKKKPKN 67

calponin homology (CH) domain found in alpha-Pak Interactive eXchange factor; Alpha-Pak Interactive eXchange factor (alpha-PIX), also called PAK-interacting exchange factor alpha, Rho guanine nucleotide exchange factor 6 (ARHGEF6), Rac/Cdc42 guanine nucleotide exchange factor 6, or Cool (Cloned out of Library)-2, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac1, and is localized in dendritic spines where it regulates spine morphogenesis. It controls dendritic length and spine density in the hippocampus. Mutations in the ARHGEF6 gene cause X-linked intellectual disability in humans. Alpha-PIX contains a single copy of the CH domain at its N-terminus. CH domains are actin filament (F-actin) binding motifs.

                         10        20
                 ....*....|....*....|..
gi 554506520  52 LKDGIILCELINKLQPGSVKKV 73
Cdd:cd21265   35 LKDGVVLCKLIERLLPGSVEKY 56

calponin homology (CH) domain found in beta-Pak Interactive eXchange factor; Beta-Pak Interactive eXchange factor (beta-PIX), also called PAK-interacting exchange factor beta, Rho guanine nucleotide exchange factor 7 (ARHGEF7), p85, or Cool (Cloned out of Library)-1, activates small GTPases by exchanging bound GDP for free GTP. It acts as a GEF for both Cdc42 and Rac1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. Beta-PIX contains a single copy of the CH domain at its N-terminus. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30
                 ....*....|....*....|....*....|....*....
gi 554506520  48 FQLGLKDGIILCELINKLQPGSVKKVnesslnWPQAKTK 86
Cdd:cd21266   29 LQASLKDGVVLCRLLERLLPGSIDKV------YPEPRTE 61

calponin homology (CH) domain found in the IQ motif containing GTPase activating protein family; Members of the IQ motif containing GTPase activating protein (IQGAP) family are associated with the Ras GTP-binding protein and act as essential regulators of cytoskeletal function. There are three known IQGAP family members: IQGAP1, IQGAP2, and IQGAP3. They are multi-domain molecules having a calponin-homology (CH) domain which binds F-actin, IQGAP-specific repeats, a single WW domain, four IQ motifs that mediate interactions with calmodulin, and a RasGAP related domain that binds active Rho family GTPases. IQGAP1 negatively regulates Ras family GTPases by stimulating their intrinsic GTPase activity. It lacks GAP activity. Both IQGAP1 and IQGAP2 specifically bind to Cdc42 and Rac1, but not to RhoA. Despite similarities to part of the sequence of RasGAP, neither IQGAP1 nor IQGAP2 interacts with Ras. IQGAP3 regulates the organization of the cytoskeleton under the regulation of Rac1 and Cdc42 in neuronal cells. The depletion of IQGAP3 is shown to impair neurite or axon outgrowth in neuronal cells with disorganized cytoskeleton.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 554506520  30 EDLRNWIEEVTGMSIGP--NFQLGLKDGIILCELINKLQPGSV--KKVNESSLNW 80
Cdd:cd21206   11 EEAKQWIEACLNEELPPttEFEEELRNGVVLAKLANKFAPKLVplKKIYDVGLQF 65

calponin homology (CH) domain found in transgelin; Transgelin, also called 22 kDa actin-binding protein, protein WS3-10, or smooth muscle protein 22-alpha (SM22-alpha), acts as an actin cross-linking/gelling protein that may be involved in calcium interactions and in regulating contractile properties of the cell. It may also contribute to replicative senescence. Transgelin contains a single copy of the CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 554506520  25 DHQAEEDLRNWIEEVTGMSIG-PN-----FQLGLKDGIILCELINKLQPGSVKKV 73
Cdd:cd21279    1 DEELEERLVEWIVVQCGPDVGrPDrgrlgFQVWLKNGVVLSKLVNSLYPDGSKPV 55

third calponin homology (CH) domain found in the plastin/fimbrin family; This family includes plastin and fimbrin. Plastin has three isoforms, plastin-1, -2, and -3. Plastin-1, also called intestine-specific plastin, or I-plastin, is an actin-bundling protein in the absence of calcium. Plastin-2, also called L-plastin, or LC64P, or lymphocyte cytosolic protein 1 (LCP-1), is an actin-binding protein that plays a role in the activation of T-cells in response to costimulation through TCR/CD3 and CD2 or CD28. It modulates the cell surface expression of IL2RA/CD25 and CD69. Plastin-3, also called T-plastin, is an actin-bundling protein found in intestinal microvilli, hair cell stereocilia, and fibroblast filopodia. It may play a role in the regulation of bone development. Fimbrin has been found in plants and fungi. Arabidopsis thaliana fimbrin (AtFIM) includes fimbrin-1, -2, -3, -4, and -5, which cross-link actin filaments (F-actin) in a calcium independent manner. They stabilize and prevent F-actin depolymerization mediated by profilin. They act as key regulators of actin cytoarchitecture, probably involved in cell cycle, cell division, cell elongation and cytoplasmic tractus. AtFIM5 is an actin bundling factor that is required for pollen germination and pollen tube growth. Fungal fimbrin binds to actin, and functionally associates with actin structures involved in the development and maintenance of cell polarity. Members of this family contain four copies of the CH domain. This model corresponds to the third CH domain. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 554506520  27 QAEEDLRNWIEEVTGMSIGPNFQLGLKDGIILCELINKLQPGSV--KKVN 74
Cdd:cd21219    4 REERAFRMWLNSLGLDPLINNLYEDLRDGLVLLQVLDKIQPGCVnwKKVN 53