Rivailler P, Krantic S
Ecole Normale Supérieure, Laboratoire de Biologie Moléculaire et Cellulaire, Lyon, France.
Biochem Pharmacol. 1996 Jan 12;51(1):77-82. doi: 10.1016/0006-2952(95)02129-9.
In Spisula solidissima oocytes, serotonin (5-hydroxytryptamine, 5-HT)-dependent meiosis reinitiation is mediated via specific 5-HT membrane binding sites. This oocyte response is inhibited by the phorbol ester TPA. To assess whether the inhibitory effect of TPA was due to alteration of oocyte membrane binding sites, we studied their characteristics after TPA treatment. [3H]-5HT binding assays revealed that TPA decreased the affinity and, after prolonged treatment, increased the number of oocyte binding sites. Moreover, inhibitory actions of TPA on 5-HT-induced meiosis reinitiation paralleled its inhibitory effects on 5-HT binding site affinity. The inhibitory actions in biological assays were restricted to TPA (an inactive analog of TPA, TPA-met was inefficient) and were completely reversed by staurosporine. Our data thus suggest an inhibitory role for protein kinase C on oocyte 5-HT binding sites under physiological conditions.
在硬壳蛤卵母细胞中，5-羟色胺（5-HT）依赖的减数分裂重新启动是通过特定的5-HT膜结合位点介导的。这种卵母细胞反应受到佛波酯TPA的抑制。为了评估TPA的抑制作用是否是由于卵母细胞膜结合位点的改变，我们研究了TPA处理后它们的特性。[3H]-5HT结合试验表明，TPA降低了亲和力，并且在长时间处理后增加了卵母细胞结合位点的数量。此外，TPA对5-HT诱导的减数分裂重新启动的抑制作用与其对5-HT结合位点亲和力的抑制作用平行。生物试验中的抑制作用仅限于TPA（TPA的无活性类似物TPA-met无效），并且被星形孢菌素完全逆转。因此，我们的数据表明，在生理条件下蛋白激酶C对卵母细胞5-HT结合位点具有抑制作用。
