PROSITE documentation PDOC00808Calponin-like repeat signature and profile
Calponin [1,2] is a thin filament-associated protein that is implicated in the regulation and modulation of smooth muscle contraction. It is capable of binding to actin, calmodulin, troponin C and tropomyosin. The interaction of calponin with actin inhibits the actomyosin MgATPase activity. Calponin is a basic protein of approximately 34 Kd. Multiple isoforms are found in smooth muscles.
Calponin contains three repeats of a well conserved motif of about 26 amino acids. Such a domain is also found in a number of other proteins whose physiological role is not yet established:
- Vertebrate transgelin (also known as smooth muscle protein SM22-α) (1 copy).
- Mammalian transgelin 2.
- Drosophila synchronous flight muscle protein SM20 (1 copy).
- Rat neuronal protein NP25 [3] (1 copy).
- Caenorhabditis elegans protein unc-87 [4] (5 copies).
- An Onchocerca volvulus antigen [5] (5 copies).
Most of these proteins also contain a N-terminal CH domain (see <PDOC50021>). The calponin-like repeat is a short actin-binding module. Actin-binding sites formed by either CH domains or calponin-like repeats occupy non-competing binding sites along the actin filament [6].
We developed both a pattern and a profile for the calponin-like repeat. The signature pattern corresponds to the first 20 residues, whereas the profile covers the entire calponin-like repeat.
Last update:June 2005 / Profile added and text revised.
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PROSITE methods (with tools and information) covered by this documentation:
| 1 | Authors | Winder S.J. Walsh M.P. |
| Title | Calponin: thin filament-linked regulation of smooth muscle contraction. | |
| Source | Cell. Signal. 5:677-686(1993). | |
| PubMed ID | 8130072 |
| 2 | Authors | Applegate D.E. Feng W. Green R.S. Taubman M.B. |
| Title | Cloning and expression of a novel acidic calponin isoform from rat aortic vascular smooth muscle. | |
| Source | J. Biol. Chem. 269:10683-10690(1994). | |
| PubMed ID | 8144658 |
| 3 | Authors | Ren W.-Z. Ng G.Y.K. Wang R.-X. Wu P.H. O'Dowd B.F. Osmond D.H. George S.R. Liew C.-C. |
| Title | The identification of NP25: a novel protein that is differentially expressed by neuronal subpopulations. | |
| Source | Brain Res. Mol. Brain Res. 22:173-185(1994). | |
| PubMed ID | 8015377 |
| 4 | Authors | Goetinck S.D. Waterston R.H. |
| Title | The Caenorhabditis elegans muscle-affecting gene unc-87 encodes a novel thin filament-associated protein. | |
| Source | J. Cell Biol. 127:79-93(1994). | |
| PubMed ID | 7929573 |
| 5 | Authors | Irvine M. Huima T. Prince A.M. Lustigman S. |
| Title | Identification and characterization of an Onchocerca volvulus cDNA clone encoding a highly immunogenic calponin-like protein. | |
| Source | Mol. Biochem. Parasitol. 65:135-146(1994). | |
| PubMed ID | 7935620 |
| 6 | Authors | Lener T. Burgstaller G. Gimona M. |
| Title | The role of calponin in the gene profile of metastatic cells: inhibition of metastatic cell motility by multiple calponin repeats. | |
| Source | FEBS Lett. 556:221-226(2004). | |
| PubMed ID | 14706854 |
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