Molecular mechanism of meiotic arrest through Mos-MAPK pathway in mouse oocytes

排卵的卵母细胞在第二次减数分裂中期（中期-II）停止。在这项研究中，我们显示了有丝分裂原和应激激活激酶1，MSK 1作为Mos-MAPK通路的下游激酶，在小鼠卵母细胞中的可能作用。MSK 1具有磷酸化减数分裂细胞周期调节因子EMI 2的四个Ser/Thr残基的能力。磷酸化是卵母细胞中EMI 2活性上调所必需的。这些结果表明，小鼠MSK 1可能通过磷酸化EMI 2在中期II阻滞中发挥关键作用。

Ovulated oocytes are arrested at the metaphase of second meiotic division (metaphase-II). In this study, we showed possible role of mitogen-and stress-activated kinase 1, MSK1 known as a downstream kinase of the Mos-MAPK pathway, in the mouse oocytes. MSK1 exhibited the ability to phosphorylate four Ser/Thr residues of meiotic cell-cycle regulator EMI2. The phosphorylation was required for up-regulation of the EMI2 activity in the oocytes. These results suggested that mouse MSK1 may play a key role in the metaphase-II arrest through phosphorylation of EMI2.