Binding of Cdc42 to phospholipase D1 is important in neurite outgrowth of neural stem cells.
We previously demonstrated that phospholipase D (PLD) expression and PLD activity are upregulated during neuronal differentiation. In the present study, employing neural stem cells from the brain cortex of E14 rat embryos, we investigated the role of Rho family GTPases in PLD activation and in neurite outgrowth of neural stem cells during differentiation. As neuronal differentiation progressed, the expression levels of Cdc42 and RhoA increased. Furthermore, Cdc42 and PLD1 were mainly localized in neurite, whereas RhoA was localized in cytosol. Co-immunoprecipitation revealed that Cdc42 was bound to PLD1 during differentiation, whereas RhoA was associated with PLD1 during both proliferation and differentiation. These results indicate that the association between Cdc42 and PLD1 is related to neuronal differentiation. To examine the effect of Cdc42 on PLD activation and neurite outgrowth, we transfected dominant negative Cdc42 (Cdc42N17) and constitutively active Cdc42 (Cdc42V12) into neural stem cells, respectively. Overexpression of Cdc42N17 decreased both PLD activity and neurite outgrowth, whereas co-transfection with Cdc42N17 and PLD1 restored them. On the other hand, Cdc42V12 increased both PLD activity and neurite outgrowth, suggesting that active state of Cdc42 is important in upregulation of PLD activity which is responsible for the increase of neurite outgrowth.
Yoon
Mee-Sup
MS
Department of Biochemistry and Molecular Biology, College of Medicine, Hanyang University, Seoul, Republic of Korea.
Cho
Chan Ho
CH
Lee
Ki Sung
KS
Han
Joong-Soo
JS
D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D016501:Neurites / Q000378:metabolism*; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism*; D020764:cdc42 GTP-Binding Protein / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D010739:Phospholipase D; C106801:phospholipase D1; D020764:cdc42 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein