Caldesmon (IPR006017)

Short name: Caldesmon

Overlapping homologous superfamilies


Family relationships


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 [PMID: 1555769]. CDM is believed 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 [PMID: 1555769].

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 muscle or heart).

A short CDM has been cloned from a chicken gizzard library [PMID: 1939602]. The predicted protein contains 524 amino acids, with molecular mass ~60 kDa. The expressed protein binds to F-actin and is retained on calmodulin- Sepharose in the presence of Ca2+ [PMID: 1939602]. Like the human non-muscle form [PMID: 1555769], 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 central segment, which is thought to be helical, renders the non-muscle protein ~35nm shorter than smooth muscle CDM [PMID: 1939602].

GO terms

Biological Process

GO:0006936 muscle contraction

Molecular Function

GO:0003779 actin binding
GO:0005516 calmodulin binding
GO:0017022 myosin binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.