Analysis of myosin light chain phosphopeptides in phorbol dibutyrate-contracted artery.
The incorporation of [32P]phosphate into the 20 kDa myosin light chain of phorbol dibutyrate-contracted artery was slightly increased as compared to that of resting muscle. Addition of K+ to the 1-h phorbol dibutyrate-contracted artery immediately doubled the force and greatly increased the light chain phosphorylation. Two-dimensional phosphopeptide mapping of light chain from phorbol dibutyrate-contracted muscle showed distinct peptides phosphorylated on serine residues by myosin light chain kinase and protein kinase C. In addition, the peptide phosphorylated on threonine residue by protein kinase C was revealed for the first time in intact muscle. Upon addition of K+, the distribution of phosphopeptides shifted toward the myosin light chain kinase catalyzed pattern.
Bárány
K
K
Department of Physiology and Biophysics, College of Medicine, University of Illinois, Chicago 60612.
Rokolya
A
A
Bárány
M
M
D000818:Animals; D009119:Muscle Contraction; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism*; D010449:Peptide Mapping; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010748:Phosphopeptides / Q000378:metabolism*; D010766:Phosphorylation; D011188:Potassium / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D013552:Swine
D010748:Phosphopeptides; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D009219:Myosin-Light-Chain Kinase; D011188:Potassium