Translational repression by the oocyte-specific protein P100 in Xenopus

The translational regulation of maternal mRNAs is one of the most important steps in the control of temporal-spatial gene expression during oocyte maturation and early embryogenesis in various species Recently, it has become clear that protein components of mRNPs play essential roles in the translational regulation of maternal mRNAs In the present study, we investigated the function of P100 in Xenopus oocytes P100 exhibits sequence conservation with budding yeast Pail and is likely the orthologue of human Patla (also called PatL2) P100 is maternally expressed in Immature oocytes, but disappears during oocyte maturation In oocytes, P100 is an RNA binding component of ribosome-free mRNPs, associating with other mRNP components such as Xp54, xRAP55 and CPEB Translational repression by overexpression of P100 occurred when reporter mRNAs were injected into oocytes Intriguingly, we found that when P100 was overexpressed in the oocytes. the kinetics of oocyte maturation was considerably retarded In addition, overexpression of P100 in oocytes significantly affected the accumulation of c-Mos and cyclin B1 during oocyte maturation. These results suggest that P100 plays a role in regulating the translation of specific maternal mRNAs required for the progression of Xenopus oocyte maturation (C) 2010 Elsevier Inc All rights reserved