Modulation of Ca(v)3.2 T-type Ca2+ channels by protein kinase C.
Although T-type Ca2+ channels have been implicated in numerous physiological functions, their regulations by protein kinases have been obscured by conflicting reports. We investigated the effects of protein kinase C (PKC) on Ca(v)3.2 T-type channels reconstituted in Xenopus oocytes. Phorbol-12-myristate-13-acetate (PMA) strongly enhanced the amplitude of Ca(v)3.2 channel currents (approximately 3-fold). The augmentation effects were not mimicked by 4alpha-PMA, an inactive stereoisomer of PMA, and abolished by preincubation with PKC inhibitors. Our findings suggest that PMA upregulates Ca(v)3.2 channel activity via activation of oocyte PKC.
Park
Jin-Yong
JY
Department of Life Science, Sogang University, Shinsu-dong, Mapo-Gu, 121-742, Seoul, South Korea.
Jeong
Seong-Woo
SW
Perez-Reyes
Edward
E
Lee
Jung-Ha
JH
D000818:Animals; D020747:Calcium Channels, T-Type / Q000502:physiology*; D003001:Cloning, Molecular; D006801:Humans; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009865:Oocytes / Q000187:drug effects / Q000502:physiology; D011493:Protein Kinase C / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014981:Xenopus
C479952:CACNA1H protein, human; D020747:Calcium Channels, T-Type; D011994:Recombinant Proteins; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate