Caldesmon 1 (CALD1)

Caldesmon 1 is a multidomain cytoskeletal regulatory protein encoded by the CALD1 gene, highly conserved in vertebrates and present in both smooth muscle and nonmuscle cells[1][2][3][5]. It binds actin, myosin, calmodulin, and tropomyosin, and functions as an important mediator of actin-myosin interaction, acting as a potent inhibitor of the actin-tropomyosin activated myosin ATPase[1][2][5]. Caldesmon is regulated by Ca2+/calmodulin binding and phosphorylation, mediating Ca2+-dependent inhibition of smooth muscle contraction and modulating cell shape, motility, mitosis, and cytoskeletal dynamics[1][2][3][6]. Alternative splicing of CALD1 gives rise to tissue-specific isoforms (notably "high-molecular-weight" H-caldesmon in muscle and "low-molecular-weight" L-caldesmon in nonmuscle cells)[1][3]. Caldesmon is not recognized as a current direct therapeutic target, but has utility as a histopathological marker in oncology, muscle pathology, and for distinguishing soft tissue tumor subtypes[1][5].

Other names

CaldesmonCADCDMH-CADL-CADh-CDHCADLCADNAG22testis secretory sperm-binding protein Li 227n