Ca2+-dependent phosphorylation and Ca2+ uptake in membrane fractions of the mesenteric artery

Ca2+-dependent phosphorylation of endogenous substrate proteins (mol. wt 30 800, 35 500, 38 600 and 53 200) is found in a membrane subcellular fraction from rabbit mesenteric arteries. Characteristics of32P incorporation are suggestive of a phosphoester-type phosphorylation produced by a Ca2+-dependent protein kinase.