A Phospholipase C-Dependent Inositol Polyphosphate Kinase Pathway Required for Efficient Messenger RNA Export

Abstract

In order to identify additional factors required for nuclear export of messenger RNA, a genetic screen was conducted with a yeast mutant deficient in a factor Gle1p, which associates with the nuclear pore complex (NPC). The three genes identified encode phospholipase C and two potential inositol polyphosphate kinases. Together, these constitute a signaling pathway from phosphatidylinositol 4,5-bisphosphate to inositol hexakisphosphate (IP 6 ). The common downstream effects of mutations in each component were deficiencies in IP 6 synthesis and messenger RNA export, indicating a role for IP 6 in GLE1 function and messenger RNA export.