Seroatlas · Protein domains

CH domain superfamily

IPR036872

Definition

A number of actin-binding proteins, including spectrin, alpha-actinin and fimbrin, contain a 250 amino acid stretch called the actin binding domain (ABD). The ABD has probably arisen from duplication of a domain which is also found in a single copy in a number of other proteins like calponin or the vav proto-oncogene and has been called calponin homology (CH) domain [[cite:PMID:9708889], [cite:PMID:9887274]]. A detailed analysis of The CH domain-containing proteins has shown that they can be divided in three groups PMID:9708889: The fimbrin family of monomeric actin cross-linking molecules containing two ABDs Dimeric cross-linking proteins (alpha-actinin, beta-spectrin, filamin, etc.) and monomeric F-actin binding proteins (dystrophin, utrophin) each containing one ABD Proteins containing only a single amino terminal CH domain Each single ABD, comprising two CH domains, is able to bind one actin monomer in the filament. The N-terminal CH domain has the intrinsic ability to bind actin, albeit with lower affinity than the complete ABD, whereas the C-terminal CH bind actin extremely weakly or not at all. Nevertheless both CH domains are required for a fully functional ABD; the C-terminal CH domain contributing to the overall stability of the complete ABD through inter-domain helix-helix interactions PMID:9708889. Some of the proteins containing a single CH domain also bind to actin, although this has not been shown to be via the single CH domain alone PMID:9887274. In addition, the CH domain occurs also in a number of proteins not known to bind actin, a notable example being the vav protooncogene. The resolution of the 3D structure of various CH domains has shown that the conserved core consist of four major α-helices PMID:9887274. Proteins containing a calponin domain include: Calponin, which is involved in the regulation of contractility and organisation of the actin cytoskeleton in smooth muscle cells PMID:11839310. Beta-spectrin, a major component of a submembrane cytoskeletal network connecting actin filaments to integral plasma membrane proteins PMID:17121810. The actin-cross-linking domain of the fimbrin/plastin family of actin filament bundling or cross-linking proteins PMID:9302997. Utrophin,a close homologue of dystrophin PMID:9887274. Dystrophin, the protein found to be defective in Duchenne muscular dystrophy; this protein contains a tandem repeat of two CH domains PMID:10801490. Actin-binding domain of plectin, a large and widely expressed cytolinker protein PMID:15128297. The N-terminal microtubule-binding domain of microtubule-associated protein eb1 (end-binding protein), a member of a conserved family of proteins that localise to the plus-ends of microtubules PMID:12857735. Ras GTPase-activating-like protein rng2, an IQGAP protein that is essential for the assembly of an actomyosin ring during cytokinesis PMID:15272162. Transgelin, which suppresses androgen receptor transactivation PMID:17082327.

82 human proteins with this domain

Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.

Download CSV (82 proteins: gene, accession, name)

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