CYK-4 functions independently of its centralspindlin partner ZEN-4 to cellularize oocytes in germline syncytia

• DOI: 10.7554/elife.36919
• Publication Date: 2018-07-10T12:00:39Z
• Authors: Kian-Yong Lee; Rebecca A Green; Edgar Gutierrez; J Sebastian Gomez...; Irina Kolotuev; Shaohe Wang; Arshad Desai; Alex Groisman; Karen Oegema
• Keywords: Syncytium

Throughout metazoans, germ cells undergo incomplete cytokinesis to form syncytia connected by intercellular bridges. Gamete formation ultimately requires bridge closure, yet how bridges are reactivated close is not known. The most conserved component centralspindlin, a complex of the Rho family GTPase-activating protein (GAP) CYK-4/MgcRacGAP and microtubule motor ZEN-4/kinesin-6. Here, we show that oocyte production syncytial Caenorhabditis elegans germline CYK-4 but ZEN-4, which contrasts with cytokinesis, where both essential. Longitudinal imaging after conditional inactivation revealed activity important for cellularization, cytokinesis-like events generate compartments. CYK-4’s lipid-binding C1 domain GTPase-binding interface its GAP were required target cellularize oocytes. These results suggest C1-GAP region constitutes targeting module closure in syncytia.