Characterization of the binding and phosphorylation of cardiac calsequestrin by epsilon protein kinase C.
In this study, we report the cloning of the rat cardiac isoform of calsequestrin on the basis of its interaction with an epsilonprotein kinase C-unique sequence (epsilonV1) derived form the epsilonprotein kinase C regulatory domain. Calsequestrin binds activated epsilonprotein kinase C holoenzyme better than the inactive enzyme and nearly three times better than other protein kinase C isozymes. The interaction between epsilonprotein kinase C and calsequestrin is mediated by sequences in both the regulatory and kinase domains of the epsilonprotein kinase C. Finally, we show that calsequestrin is an epsilonprotein kinase C substrate in vitro and protein kinase C phosphorylation of calsequestrin leads to a decreased binding of epsilonprotein kinase C to calsequestrin.
Rodriguez
M M
MM
Department of Molecular Pharmacology, Stanford University School of Medicine, CA 94305-5332, USA.
Chen
C H
CH
Smith
B L
BL
Mochly-Rosen
D
D
D000595:Amino Acid Sequence; D000818:Animals; D002155:Calsequestrin / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D007527:Isoenzymes / Q000378:metabolism*; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D010766:Phosphorylation; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D051744:Protein Kinase C-epsilon; D051381:Rats; D017207:Rats, Sprague-Dawley; D016415:Sequence Alignment; D013379:Substrate Specificity
D002155:Calsequestrin; D007527:Isoenzymes; D020033:Protein Isoforms; C497257:Prkce protein, rat; D011493:Protein Kinase C; D051744:Protein Kinase C-epsilon