Martinez Silvana, Grandy Rodrigo, Pasten Pamela, Montecinos Hernán, Montecino Martín, Olate Juan, Hinrichs María Victoria
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Casilla 160-C, Universidad de Concepción, Concepción, Chile.
J Cell Biochem. 2006 Oct 15;99(3):853-9. doi: 10.1002/jcb.20941.
Xenopus laevis oocyte maturation is induced by the steroid hormone progesterone through a non-genomic mechanism initiated at the cell membrane. Recently, two Xenopus oocyte progesterone receptors have been cloned; one is the classical progesterone receptor (xPR-1) involved in genomic actions and the other a putative seven-transmembrane-G-protein-couple receptor. Both receptors are postulated to be mediating the steroid-induced maturation process in the frog oocyte. In this study, we tested the hypothesis that the classical progesterone receptor, associated to the oocyte plasma membrane, is participating in the reinitiation of the cell cycle. Addition of a myristoilation and palmytoilation signal at the amino terminus of xPR-1 (mp xPR-1), increased the amount of receptor associated to the oocyte plasma membrane and most importantly, significantly potentiated progesterone-induced oocyte maturation sensitivity. These findings suggest that the classical xPR-1, located at the plasma membrane, is mediating through a non-genomic mechanism, the reinitiation of the meiotic cell cycle in the X. laevis oocyte.
非洲爪蟾卵母细胞的成熟是由类固醇激素孕酮通过细胞膜起始的非基因组机制诱导的。最近，已克隆出两种非洲爪蟾卵母细胞孕酮受体；一种是参与基因组作用的经典孕酮受体（xPR - 1），另一种是假定的七跨膜G蛋白偶联受体。两种受体都被认为介导了蛙卵母细胞中类固醇诱导的成熟过程。在本研究中，我们检验了这样一个假设，即与卵母细胞质膜相关的经典孕酮受体参与了细胞周期的重新启动。在xPR - 1的氨基末端添加肉豆蔻酰化和棕榈酰化信号（mp xPR - 1），增加了与卵母细胞质膜相关的受体数量，最重要的是，显著增强了孕酮诱导的卵母细胞成熟敏感性。这些发现表明，位于质膜的经典xPR - 1通过非基因组机制介导了非洲爪蟾卵母细胞减数分裂细胞周期的重新启动。
