Translational control of E2f1 regulates the Drosophila cell cycle

Abstract

Significance Here, we explore a mechanism wherein the growth signaling-dependent translation of mRNA encoding a cell cycle regulatory factor limits rates of cell proliferation. An essential cell cycle transcription factor, E2F1, was found to be post-transcriptionally regulated by TOR and EGFR signaling, and thus served as a candidate growth sensor for this study. Using expression of green fluorescent protein (GFP)-E2F1 transgenes with alterations within the E2f1 5′ untranslated region (UTR), we altered the translation of GFP-E2F1 and changed cell proliferation rates accordingly. Further, we found that 5′UTR upstream open reading frames are TOR-sensitive regulatory components of E2f1 translation. Our observations indicate that growth signaling dependent protein translation is an important regulator of cell proliferation.