Project description:The translational reactivation of maternal mRNAs encoding the drivers of vertebrate meiosis is accomplished mainly by cytoplasmic polyadenylation. The Cytoplasmic Polyadenylation Elements (CPEs) present in the 3’ UTR of these transcripts, together with their cognate CPE-binding proteins (CPEBs), define a combinatorial code that determines the timing and extent of translational activation upon meiosis resumption. In addition, the RNA-binding protein Musashi1 (Msi1) regulates the polyadenylation of CPE-containing mRNAs by an as yet undefined CPEB-dependent or -independent mechanism. Here we show that Msi1 alone does not support cytoplasmic polyadenylation, but its binding triggers the remodeling of RNA structure, thereby exposing adjacent CPEs and stimulating polyadenylation. Thus, Msi1 directs the preferential use of specific CPEs, which in turn affects the timing and extent of polyadenylation during meiotic progression. Genome-wide analysis of CPEB1- and Msi-associated mRNAs identified 491 common targets, thus revealing a new layer of CPE-mediated translational control.
Project description:The translational reactivation of maternal mRNAs encoding the drivers of vertebrate meiosis is accomplished mainly by cytoplasmic polyadenylation. The Cytoplasmic Polyadenylation Elements (CPEs) present in the 3’ UTR of these transcripts, together with their cognate CPE-binding proteins (CPEBs), define a combinatorial code that determines the timing and extent of translational activation upon meiosis resumption. In addition, the RNA-binding protein Musashi1 (Msi1) regulates the polyadenylation of CPE-containing mRNAs by an as yet undefined CPEB-dependent or -independent mechanism. Here we show that Msi1 alone does not support cytoplasmic polyadenylation, but its binding triggers the remodeling of RNA structure, thereby exposing adjacent CPEs and stimulating polyadenylation. Thus, Msi1 directs the preferential use of specific CPEs, which in turn affects the timing and extent of polyadenylation during meiotic progression. Genome-wide analysis of CPEB1- and Msi-associated mRNAs identified 491 common targets, thus revealing a new layer of CPE-mediated translational control.
Project description:The translational reactivation of maternal mRNAs encoding the drivers of vertebrate meiosis is accomplished mainly by cytoplasmic polyadenylation. The Cytoplasmic Polyadenylation Elements (CPEs) present in the 3’ UTR of these transcripts, together with their cognate CPE-binding proteins (CPEBs), define a combinatorial code that determines the timing and extent of translational activation upon meiosis resumption. In addition, the RNA-binding protein Musashi1 (Msi1) regulates the polyadenylation of CPE-containing mRNAs by an as yet undefined CPEB-dependent or -independent mechanism. Here we show that Msi1 alone does not support cytoplasmic polyadenylation, but its binding triggers the remodeling of RNA structure, thereby exposing adjacent CPEs and stimulating polyadenylation. Thus, Msi1 directs the preferential use of specific CPEs, which in turn affects the timing and extent of polyadenylation during meiotic progression. Genome-wide analysis of CPEB1- and Msi-associated mRNAs identified 491 common targets, thus revealing a new layer of CPE-mediated translational control.
Project description:Cytoplasmic polyadenylation element binding protein 1 (CPEB1) regulates polyadenylation and subsequent translation of CPE-containing mRNAs, which contributes to various physiological and pathological phenomena. To clarify changes in gene expression profiles caused by dysregulation of CPEB1 expression, we performed microarray analyses and revealed that reduced CPEB1 expression altered the expression levels of numerous genes. These findings indicate that accurate post-transcriptional regulation of CPEB1 expression contributes to the maintenance of global gene expression partially through modulating lncRNA expression.
Project description:Pancreatic cancer is a leading cause of cancer death worldwide. Cytoplasmic polyadenylation element binding protein 1 (CPEB1) is a fundamental translation regulatory factor regulating the polyadenylation process of messenger RNA. However, its biological functions in pancreatic cancer are poorly understood. Here the CPEB1 gene was knocked down or overexpressed in JF-305 cell line. To investigate the role of CPEB1 and new interacting proteins, proteomic analysis was performed using LC-MS/MS approach.
Project description:The molecular causes of deteriorating oocyte quality during aging are poorly defined. Since oocyte developmental competence relies on post-transcriptional regulations, we tested whether defective mRNA translation contributes to this decline in quality. Disruption in ribosome loading on maternal transcripts is present in old oocytes. Using a candidate approach, we detect altered translation of 3’-UTR-reporters and altered poly(A) length of the endogenous mRNAs. mRNA polyadenylation depends on the cytoplasmic polyadenylation binding protein 1 (CPEB1). Cpeb1 mRNA translation and protein levels are decreased in old oocytes. This decrease causes de-repression of Ccnb1 translation in quiescent oocytes, premature CDK1 activation, and accelerated reentry into meiosis. De-repression of Ccnb1 is corrected by Cpeb1 mRNA injection in old oocytes. Oocyte-specific Cpeb1 haploinsufficiency in young oocytes recapitulates all the translation phenotypes of old oocytes. These findings demonstrate that a dysfunction in the oocyte translation program is associated with the decline in oocyte quality during aging.