A phospholipase C-dependent inositol polyphosphate kinase pathway required for efficient messenger RNA export.

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 (IP6). The common downstream effects of mutations in each component were deficiencies in IP6 synthesis and messenger RNA export, indicating a role for IP6 in GLE1 function and messenger RNA export.