The smooth muscle 132 kDa cyclic GMP-dependent protein kinase substrate is not myosin light chain kinase or caldesmon

Abstract

Atrial natriuretic peptide (ANP) stimulates the phosphorylation of three cyclic GMP-dependent protein kinase substrate proteins of 225, 132, and 11 kDa (p225, P132 and P11 respectively) in the particulate fraction of cultured rat aortic smooth muscle cells [Sarcevic, Brookes, Martin, Kemp and Robinson (1989) J. Biol. Chem. 264, 20648-20654]. Vrolix, Raeymaekers, Wuytack, Hofmann and Casteels [(1988) Biochem. J. 255, 855-863] have reported the presence of a 130 kDa cyclic GMP-dependent protein kinase substrate protein in the membrane fraction of pig aorta or stomach, and suggested that it may be myosin light chain kinase (MLCK). The aim of the present study was to determine whether P132 from ..