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:Messenger RNA stability, localization, and translation are largely determined by sequences in their 3M-bM-^@M-2 untranslated regions (3M-bM-^@M-^YUTRs), which recruit regulatory proteins and RNAs. More than half of the mammalian genes generate multiple mRNA isoforms differing in their 3M-bM-^@M-2UTRs and therefore in their regulatory elements. The Cytoplasmic Polyadenylation Element Binding protein 1 (CPEB1) binds to cognate sites in 3M-bM-^@M-^Y UTRs and regulates translation. CPEB1 can shuttle to the nucleus and we report its co-localization with splicing factors. CPEB1 knock down leads to changes in alternative splicing, and we show that alternative 3M-bM-^@M-^Y splice site linked to alternative polyadenylation of the bub-3 pre-mRNA, important for cell proliferation, is regulated by CPEB1 at least in part by preventing 3M-bM-^@M-^Y splice site recognition by U2AF. RNA-Seq experiments reveal that CPEB1 mediates 3M-bM-^@M-^Y UTR shortening of hundreds of mRNAs, leading to changes in their translation efficiency. Three total RNA from three biological replicates were labeled and hybridized versus its own control in direct and dye-swap hybridizations.
Project description:We performed CPEB1 RIP-seq on freshly isolated muscle stem cells. We found that CPEB1 associated genes are enriched in translational regulation pathways.