Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel.
Theriogenology. 2011 Jan 1;75(1):80-9. doi: 10.1016/j.theriogenology.2010.07.013. Epub 2010 Sep 16.
In somatic cells, translocation of PKCs is facilitated by receptor for activated C kinase (RACK); however its involvement in egg activation is still elusive. We have followed the translocation pattern of conventional and novel PKCs (cPKCs and nPKCs, respectively) upon egg activation. Confocal microscopy indicated the expression and localization of RACK1, a specific receptor protein for cPKCs. Activation of MII eggs, led to translocation to the egg cortex of PKCα, βII and δ and the co-translocation of RACK1, with both PKCα and PKCβII. The association of PKC and actin, both known to be involved in cortical granules exocytosis (CGE) with RACK1, was demonstrated by co-immunoprecipitation. Egg activation resulted in an increased RACK1 level along with a decreased level of PKCβII. Based on these results, we suggest that upon egg activation, RACK1 shuttles activated cPKCs to the egg cortex, thus facilitating CGE.
在体细胞中，蛋白激酶 C（PKC）的易位是由激活的 C 激酶受体（RACK）促进的；然而，其在卵激活中的作用仍不清楚。我们已经观察了经典和新型蛋白激酶 C（cPKC 和 nPKC，分别）在卵激活时的易位模式。共聚焦显微镜显示了 RACK1 的表达和定位，这是 cPKC 的一种特异性受体蛋白。MII 期卵的激活导致 PKCα、βII 和 δ向卵皮层的易位，以及 RACK1 的共易位，PKCα 和 PKCβII 均发生易位。PKC 和肌动蛋白的结合，都已知参与皮质颗粒胞吐作用（CGE）与 RACK1 的结合，通过共免疫沉淀得到证实。卵激活导致 RACK1 水平增加，同时 PKCβII 水平降低。基于这些结果，我们认为卵激活后，RACK1 将激活的 cPKC 穿梭到卵皮层，从而促进 CGE。
