Lack of tyrosine protein kinase regulation of L-type Ca2+ channel current in transfected cells stably expressing α1c-b subunit

Abstract

Tyrosine protein kinase (Tyr-PK) regulation of L-type Ca2+ channel (CaL) current was studied in COS-7 cells expressing vascular smooth muscle-type α1C-b with no auxiliary subunit by using a whole-cell voltage clamp. The averaged peak amplitude of CaL currents was -0.33±0.03 at holding potential of -60 mV. Na3VO4, genistein and phosphorylated p60c-src peptide had no effect on the current. Thus the α1c-b subunit may not be involved in Tyr-PK regulation of GaL current.