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 Ca_V3.1 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 Ca_V3.1 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-Ca_V3.1 antibody. C) Representative macroscopic current traces recorded from HEK-293 cells stably expressing Ca_V3.1 channels in the control condition and after transfection with plasmids encoding Cdk5 and p35. Currents were elicited by depolarizing steps from a V_h 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.