RT Journal Article
SR Electronic
T1 CYK-4 functions independently of its centralspindlin partner ZEN-4 to cellularize oocytes in germline syncytia
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 196279
DO 10.1101/196279
A1 Kian-Yong Lee
A1 Rebecca A. Green
A1 Edgar Gutierrez
A1 J. Sebastian Gomez-Cavazos
A1 Irina Kolotuev
A1 Shaohe Wang
A1 Arshad Desai
A1 Alex Groisman
A1 Karen Oegema
YR 2017
UL http://biorxiv.org/content/early/2017/09/29/196279.abstract
AB Throughout metazoans, germ cells undergo incomplete cytokinesis to form syncytia connected by intercellular bridges. Formation of gametes ultimately requires bridge closure. Here, we investigate the contribution of the conserved bridge component centralspindlin to oocyte production in C. elegans. Centralspindlin is composed of the Rho family GTPase-activating protein (GAP) CYK-4/MgcRacGAP and the microtubule motor ZEN-4/kinesin-6, which are both essential for cytokinesis. In contrast, we show that oocyte production by the syncytial germline requires CYK-4 but not ZEN-4. Longitudinal imaging after conditional CYK-4 inactivation revealed a role in oocyte cellularization, rather than in generation of syncytial compartments. CYK-4’s lipid-binding C1 domain and the GTPase-binding interface of its GAP domain were individually important for oocyte cellularization and for targeting CYK-4 to bridges, where it contributes to enrichment of active RhoA. These results identify a C1-GAP module in CYK-4 that recruits it to bridges in the germline and directs their closure to produce oocytes.IMPACT STATEMENT The CYK-4 subunit of centralspindlin, a broadly conserved component of intercellular bridges across metazoa, is required for the cytokinesis-like closure of intercellular bridges that cellularizes oocytes to separate them from germline syncytia.MAJOR SUBJECT AREAS Cell Biology, Developmental Biology & Stem Cells