Caldesmon.

Recent research has led to an understanding of the in vitro properties of caldesmon, including the regulation of actomyosin ATPase activity, cross-linking between actin and myosin, enhancement of microfilament stability and stimulation of polymerization of actin. While it remains to be established whether caldesmon functions similarly in vivo, recent studies have suggested that smooth muscle caldesmon regulates the inhibition of vascular smooth muscle tone, and that non-muscle caldesmon plays roles in the regulation of cell motility and cytoskeletal organization in three biological activities: granule movement, hormone secretion and reorganization of microfilaments during mitosis.