The β 1‐subunit is essential for modulation by protein kinase C of an human and a non‐human L‐type Ca2+ channel

[摘要]

We have investigated in Xenopus oocytes the effects of phorbol ester-induced protein kinase C (PKC) stimulation on dihydropyridine (DHP)-insensitive and -sensitive Ca²⁺ channels. DHP-insensitive Ba²⁺ currents (I _Ba) were recorded from endogenous channels in non-injected oocytes and in oocytes injected with cRNAs encoding the auxiliary rabbit α ₂/δ and β ₁ Ca²⁺ channel subunits. A human α _1C cRNA, injected alone or in combination with cRNAs of the auxiliary subunits, was used for studying DHP-sensitive I _Ba. We found that DHP-insensitive I _Ba was increased by 4β-phorbol 12-myristate 13-acetate (PMA), while DHP-sensitive I _Ba was decreased. In both cases, the effects depended only on the co-expression of the β ₁ subunit.

[学科分类] 生物化学/生物物理

[关键词] Xenopus oocyte;Calcium channel;Protein kinase C