The member of Rho family of small GTPases Cdc42 plays important and conserved roles in cell polarity and motility. The Cdc42ep family proteins have been identified to bind to Cdc42, yet how they interact with Cdc42 to...The member of Rho family of small GTPases Cdc42 plays important and conserved roles in cell polarity and motility. The Cdc42ep family proteins have been identified to bind to Cdc42, yet how they interact with Cdc42 to regulate cell migration remains to be elucidated. In this study, we focus on Cdc42epl, which is expressed predominantly in the highly migratory neural crest ceils in frog embryos. Through morpholino-mediated knockdown, we show that Cdc42epl is required for the migration of cranial neural crest cells. Loss of Cdc42epl leads to rounder cell shapes and the formation of membrane blebs, consistent with the observed disruption in actin organization and focal adhesion alignment. As a result, Cdc42ep1 is critical for neural crest cells to apply traction forces at the correct place to migrate efficiently. We further show that Cdc42ep1 is localized to two areas in neural crest celts： in membrane protrusions together with Cdc42 and in perinuciear patches where Cdc42 is absent. Cdc42 directly interacts with Cdc42epl （through the CRIB domain） and changes in Cdc42 level shift the distribution of Cdc42epl between these two subcellular locations, controlling the formation of membrane protrusions and directionality of migration as a consequence. These results suggest that Cdc42ep1 elaborates Cdc42 activity in neural crest cells to promote their efficient migration.展开更多
基金This work is supported by the National Institutes of Health （ROODE022796 to S.N.） and National Science Foundation （DMR- 0955811 to J.E.C. and PHY-0848797 to J.E.C. and D.T.K.）.
文摘The member of Rho family of small GTPases Cdc42 plays important and conserved roles in cell polarity and motility. The Cdc42ep family proteins have been identified to bind to Cdc42, yet how they interact with Cdc42 to regulate cell migration remains to be elucidated. In this study, we focus on Cdc42epl, which is expressed predominantly in the highly migratory neural crest ceils in frog embryos. Through morpholino-mediated knockdown, we show that Cdc42epl is required for the migration of cranial neural crest cells. Loss of Cdc42epl leads to rounder cell shapes and the formation of membrane blebs, consistent with the observed disruption in actin organization and focal adhesion alignment. As a result, Cdc42ep1 is critical for neural crest cells to apply traction forces at the correct place to migrate efficiently. We further show that Cdc42ep1 is localized to two areas in neural crest celts： in membrane protrusions together with Cdc42 and in perinuciear patches where Cdc42 is absent. Cdc42 directly interacts with Cdc42epl （through the CRIB domain） and changes in Cdc42 level shift the distribution of Cdc42epl between these two subcellular locations, controlling the formation of membrane protrusions and directionality of migration as a consequence. These results suggest that Cdc42ep1 elaborates Cdc42 activity in neural crest cells to promote their efficient migration.
