Regulation of heterologously expressed CaV3.1 channels by Cdk5.
A) Protein extracted from mouse brain (mBrain), N1E-115 cells, untransfected HEK-293 cells as well as stably expressing CaV3.1 channel cells were analyzed by Western blot using specific antibodies for Cdk5 (upper panel) and its activator p35 (lower panel). B) Immunofluorescence analysis of HEK-293 cells stably expressing CaV3.1 channels. The confocal image illustrates the expression of the channels (green) both in the plasma membrane and the cytosol. Cells were fixed and stained with a polyclonal anti-CaV3.1 antibody. C) Representative macroscopic current traces recorded from HEK-293 cells stably expressing CaV3.1 channels in the control condition and after transfection with plasmids encoding Cdk5 and p35. Currents were elicited by depolarizing steps from a Vh of −80|mV to −30|mV. Ca2+ (10 mM) was used as the charge carrier. D) Comparison of normalized current density-voltage relationships in control and Cdk5/p35 transfected HEK-293 cells.