Chapter 1 Roles of Caldesmon in Cell Motility and Actin Cytoskeleton Remodeling

Autor: Jim J.-C. Lin, Robbin D. Eppinga, Yan Li, Jian Ping Jin, Qinchuan Wang
Rok vydání: 2009
Předmět:
DOI: 10.1016/s1937-6448(08)02001-7
Popis: Caldesmon (CaD) is a multimodular protein that regulates contractility and actin cytoskeleton remodeling in smooth muscle and nonmuscle cells. A single gene (CALD1) encodes high molecular mass CaD (h-CaD) and low molecular mass CaD (l-CaD) by alternative splicings. The h-CaD exclusively expresses in smooth muscle, whereas the l-CaD ubiquitously expresses in all cell types except skeletal muscle. The h-CaD/l-CaD ratio could be a marker for monitoring differentiating and pathological states of smooth muscles. The l-CaD associates with stress fibers and membrane ruffles in nonmuscle cells and with the actin core of podosomes in highly motile/invasive cells. Together with tropomyosin, CaD stabilizes actin filaments and inhibits actin-tropomyosin-activated myosin ATPase activity. This inhibition can be effectively released by Ca(2+)-calmodulin and/or by phosphorylation with various kinases. Through its interactions with a spectrum of actin-binding proteins, CaD modulates dynamics of cortical actin networks and stress fibers, which are essential to cell motility and cytoskeleton rearrangement. Regulation of CaD level and its activity may provide a novel strategy for gene therapy.
Databáze: OpenAIRE