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        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958666164   1 MAFKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGSVAVTKDDGCYRGEPSWFHRK 70
Cdd:cd21280    68 MAFKQMEQISQFLQAAERYGINTTDIFQTVDLWEGKNMASVQRTLMNLGGLAVTRDDGLFVGDPNWFPKK 137

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 1958666164   1 MAFKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGSVAVTKDDGCYRGEPSWFHRK 70
Cdd:cd21280    68 MAFKQMEQISQFLQAAERYGINTTDIFQTVDLWEGKNMASVQRTLMNLGGLAVTRDDGLFVGDPNWFPKK 137

Calponin family repeat;

                          10        20
                  ....*....|....*....|....*
gi 1958666164  90 IGLQMGSNKGASQAGMTGYGMPRQI 114
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 1958666164   1 MAFKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGSVAVTKDDGCYRGEPSWFHRK 70
Cdd:cd21280    68 MAFKQMEQISQFLQAAERYGINTTDIFQTVDLWEGKNMASVQRTLMNLGGLAVTRDDGLFVGDPNWFPKK 137

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
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958666164   1 MAFKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGSVAVTKDD 57
Cdd:cd21209    63 MAFKQMEQISQFLKAAEDYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGSLAVTKDD 119

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 1958666164   1 MAFKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGS 50
Cdd:cd21207    58 MAFKLMENIENFLTACKGYGVPKTDLFQTVDLYEKKNIPQVTNCLFALGR 107

calponin homology (CH) domain found in Saccharomyces cerevisiae transgelin (SCP1) and similar proteins; The family includes transgelins from Saccharomyces cerevisiae and Schizosaccharomyces pombe, which are also called SCP1 and STG1, respectively. Transgelin, also called calponin homolog 1, has actin-binding and actin-bundling activity. It stabilizes actin filaments against disassembly. Transgelin contains a single copy of the CH domain. CH domains are actin filament (F-actin) binding motifs.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1958666164   1 MAFKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALG 49
Cdd:cd21210    52 MPFVQMENISAFLNAARKLGVPENDLFQTVDLFERKNPAQVLQCLHALS 100

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
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958666164   5 QMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGSVAVTK 55
Cdd:cd21284    60 QLENIGNFIKAIQAYGMKPHDIFEANDLFENGNMTQVQTTLLALAGLAKTK 110

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 1958666164   1 MAFKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMALGS 50
Cdd:cd00014    54 SPFKKRENINLFLNACKKLGLPELDLFEPEDLYEKGNLKKVLGTLWALAL 103

Calponin family repeat;

                          10        20
                  ....*....|....*....|....*
gi 1958666164  90 IGLQMGSNKGASQAGMTGYGMPRQI 114
Cdd:pfam00402   1 IGLQMGTNKGASQSGMTAFGAVRHI 25

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
                  ....*....|....*....|....*....|....*....|....*.
gi 1958666164   3 FKQMEQISQFLKAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMAL 48
Cdd:cd21206    65 FRHTDNINHFLRALKKIGLPKIFHFETTDLYEKKNIPKVIYCLHAL 110

calponin homology (CH) domain found in VAV1 protein; VAV1 is expressed predominantly in the hematopoietic system and it plays an important role in the development and activation of B and T cells. It is activated by tyrosine phosphorylation to function as a guanine nucleotide exchange factor (GEF) for Rho GTPases following cell surface receptor activation, triggering various effects such as cytoskeletal reorganization, transcription regulation, cell cycle progression, and calcium mobilization. It also serves as a scaffold protein and has been shown to interact with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76, and Syk, among others. VAV proteins contain several domains that enable their function: N-terminal calponin homology (CH), acidic, RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two SH3 domains. This model corresponds to the CH domain, an actin-binding domain which is present as a single copy in VAV1 protein.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1958666164   8 QISQFL----------KAAEVYGVRTTDIFQTVDLWEGKDMAAVQRTLMAL 48
Cdd:cd21262    64 QMSQFLclknirtflsTCCEKFGLRKSELFEAFDLFDVRDFGKVIDTLSIL 114