Regulation of CA(v)3.2 Ca2+ channel activity by protein tyrosine phosphorylation.
Calcium entry through Cav3.2 Ca2+ channels plays essential roles for various physiological events including thalamic oscillation, muscle contraction, hormone secretion, and sperm acrosomal reaction. In this study, we examined how protein tyrosine phosphatases or protein tyrosine kinases affect Cav3.2 Ca2+ channels reconstituted in Xenopus oocytes. We found that Cav3.2 channel activity was reduced by 25% in response to phenylarsine oxide (tyrosine phosphatase inhibitor), whereas it was augmented by 19% in response to Tyr A47 or herbimycin A (tyrosine kinase inhibitors). However, other biophysical properties of Cav3.2 currents were not significantly changed by the drugs. These results imply that Cav3.2 channel activity is capable of being increased by activation of tyrosine phosphatases, but is decreased by activation of tyrosine kinases.
Huh
Sung-Un
SU
Department of Life Science, Sogang University, Seoul 121-742, Korea.
Kang
Ho-Won
HW
Park
Jin-Yong
JY
Lee
Jung-Ha
JH
D000818:Animals; D001152:Arsenicals / Q000494:pharmacology; D020747:Calcium Channels, T-Type / Q000235:genetics / Q000378:metabolism*; D004594:Electrophysiology / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D009865:Oocytes / Q000201:enzymology / Q000378:metabolism; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*; D014981:Xenopus / Q000378:metabolism; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism
D001152:Arsenicals; C479952:CACNA1H protein, human; D020747:Calcium Channels, T-Type; D004791:Enzyme Inhibitors; D029867:Xenopus Proteins; C029341:oxophenylarsine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D017027:Protein Tyrosine Phosphatases