Final Activity Report Summary - CYTOPLASMIC POLYADEN (Translational control by cytoplasmic polyadenylation during the cell cycle)
This research project addressed the role of cytoplasmic polyadenylation in coordinating gene expression during the mitotic cell cycle. By conducting a genome wide screening it was found that a population of mRNAs had a long poly(A) tail at early S phase and these mRNAs became deadenylated later on during both S and M phase, while in G1 phase they started to become polyadenylated again. The analysis of the sequences of these mRNAs should allow for the identification of Cytoplasmic polyadenylation elements (CPE) and other putative regulatory elements important for the cell cycle dependent polyadenylation. The activity of factors associated to these elements, such as CPEB, was also examined and it was found that CPEB1, 2 and 4 mediated translational regulation by cytoplasmic polyadenylation in xenopus oocytes.
The regulation mechanism of these CPEBs activity and factors associated to them remained to be explored. The putative CPEB protein responsible for cell cycle regulation of these mRNAs was being characterised, by the time of the project completion, and CPEBs knockdown experiments were anticipated to shed light on the impact of cell cycle progression. The final goal was to define the relevance of control of gene expression by cytoplasmic polyadenylation during the mitotic cell cycle.