Autophosphorylation of beta-connectin (titin 2) in vitro.
Phosphorylation of beta-connectin (titin 2), an elastic protein of chicken breast muscle, occurred in the presence of [gamma-32P] ATP, 0.2 mM CaCl2 and 25 mM phosphate buffer, pH 7.0. Addition of 3 mM MgCl2 did not affect the phosphorylation. However, Ca2+ ions were required for the phosphorylation and EGTA inhibited it even if MgCl2 were present. Myosin light chain kinase (gizzard MLCK), cAMP dependent protein kinase (A kinase), and protein kinase C (C kinase) did not phosphorylate beta-connectin in vitro under optimal conditions. Thus it appears that beta-connectin, possibly containing a domain homologous with MLCK, has an autophosphorylating action.
Takano-Ohmuro
H
H
Department of Pharmacology, Faculty of Medicine, University of Tokyo, Japan.
Nakauchi
Y
Y
Kimura
S
S
Maruyama
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002645:Chickens / Q000378:metabolism; D064211:Connectin; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D009124:Muscle Proteins / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism
D064211:Connectin; D009124:Muscle Proteins; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D011493:Protein Kinase C; D009219:Myosin-Light-Chain Kinase; D008274:Magnesium; D002118:Calcium