Conformation-dependent activation of type II adenylyl cyclase by protein kinase C

✍ Scribed by Toshiaki Ebina; Jun-ichi Kawabe; Toshiaki Katada; Shigeo Ohno; Charles J. Homcy; Yoshihiro Ishikawa

• Book ID: 101260296
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 108 KB
• Volume: 64
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/(sici)1097-4644(19970301)64:3<492::aid-jcb15>3.0.co;2-i

✦ Synopsis

Phorbol ester treatment enhanced the catalytic activity of type II adenylyl cyclase overexpressed in insect cells. In cells coexpressing type II adenylyl cyclase and protein kinase C-a, type II adenylyl cyclase catalytic activity was higher even in the absence of phorbol ester treatment; phorbol ester treatment further and markedly enhanced type II adenylyl cyclase catalytic activity. However, this enhancement, either by phorbol ester treatment or by coexpression of protein kinase C-a, was lost following membrane solubilization with detergents. This attenuation was unaffected by phosphatase inhibitor or salts. In contrast, membrane solubilization did not affect forskolin-stimulated type II adenylyl cyclase catalytic activity. Purified type II adenylyl cyclase was stimulated by forskolin and Gsa, but not by protein kinase C-a. Therefore, a specific mammalian protein kinase C isoenzyme can activate type II adenylyl cyclase, but the mechanism clearly differs from that underlying either Gsa-or forskolin-mediated stimulation.