Identification and subcellular localization of the subunits of l-type calcium channels and adenylyl cyclase in cardiac myocytes

Tianyan Gao, Tipu S. Puri, Brian L. Gerhardstein, Andy J. Chien, Richard D. Green, M. Marlene Hosey

Research output: Contribution to journalArticlepeer-review

153 Scopus citations


The properties of cardiac L-type channels have been well characterized electrophysiologically, and many such studies have demonstrated that the channels are regulated by a cAMP-dependent pathway. However, the subunit composition of native cardiac L-type calcium channels has not been completely defined. Furthermore, a very important question exists regarding the status of the C-terminal domain of the pore-forming α1 subunit, as this domain has the potential to be the target of protein kinases but may he truncated as a result of post-translational processing. In the present studies, the α(1C) and β2 subunits were identified by subunit-specific antibodies after partial purification from heart membranes, or immunoprecipitation from cardiac myocytes. Both the β2 and the full-length α(1C) subunits were found to he expressed and co-localized in intact cardiac myocytes along T- tubule membranes. Using a quantitative antibody binding analysis, we demonstrated that the majority of the α(1C) subunits in intact cardiac myocytes appear to be full-length. In addition, we observed that adenylyl cyclase is localized in a pattern similar to the channel subunits in cardiac myocytes. Taken together, our results provide new insights into the structural basis for understanding the regulation of L-type calcium channels by a cAMP-mediated signaling pathway.

Original languageEnglish
Pages (from-to)19401-19407
Number of pages7
JournalJournal of Biological Chemistry
Issue number31
StatePublished - Aug 1 1997

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Identification and subcellular localization of the subunits of l-type calcium channels and adenylyl cyclase in cardiac myocytes'. Together they form a unique fingerprint.

Cite this