Protein Domain : Caldesmon IPR006017

Type	Family
Description	Caldesmon (CDM) is an actin- and myosin-binding protein implicated in the regulation of actomyosin interactions in smooth muscle and non-muscle cells,possibly acting as a bridge between myosin and actin filaments [ ]. CDM isbelieved to be an elongated molecule, with an N-terminal myosin/calmodulin- binding domain and a C-terminal tropomyosin/actin/calmodulin-binding domain,separated by a 40nm-long central helix [ ].A high-molecular-weight form of CDM is predominantly expressed in smooth muscles, while a low-molecular-weight form is widely distributed in non-muscle tissues and cells (the protein is not expressed in skeletal muscleor heart). A short CDM has been cloned from a chicken gizzard library [ ]. The predicted protein contains 524 amino acids, with molecular mass ~60kDa. The expressed protein binds to F-actin and is retained on calmodulin-Sepharose in the presence of Ca 2+[ ]. Like the human non-muscle form [],this CDM is identical to the smooth muscle protein at its N- and C-termini, but is missing 232 amino acids from the centre. Lack of this centralsegment, which is thought to be helical, renders the non-muscle protein ~35nm shorter than smooth muscle CDM [].
Short Name	Caldesmon