title: Neurite outgrowth from PC12 cells by basic fibroblast growth factor (bFGF) is mediated by RhoA inactivation through p190RhoGAP and ARAP3.
abstract: The rat pheochromocytoma cell line PC12 has been widely used as a model to study neuronal differentiation. PC12 cells give rise to neurites in response to basic fibroblast growth factor (bFGF). However, it is unclear whether bFGF promotes neurite outgrowth by inducing RhoA inactivation, and a mechanism for RhoA inactivation in PC12 cells in response to bFGF has not been reported. Lysophosphatidic acid (LPA) treatment and the expression of constitutively active (CA)-RhoA (RhoA V14) impaired neurite formation in response to bFGF, while Tat-C3 exoenzyme and the expression of dominant negative (DN)-RhoA (RhoA N19) stimulated neurite outgrowth. GTP-bound RhoA levels were reduced in response to bFGF, which suggests that the inactivation of RhoA is essential to neurite outgrowth in response to bFGF. To investigate the mechanism of RhoA inactivation, this study examined the roles of p190RhoGAP and Rap-dependent RhoGAP (ARAP3). DN-p190RhoGAP prevented neurite outgrowth, while WT-p190RhoGAP and Src synergistically stimulated neurite outgrowth; these findings suggest that bFGF promotes the inactivation of RhoA and subsequent neurite outgrowth through p190RhoGAP and Src. Furthermore, DN-Rap1 and DN-ARAP3 reduced neurite formation in PC12 cells. These results suggest that RhoA is likely to be inactivated by p190RhoGAP and ARAP3 during neurite outgrowth in response to bFGF.
authors.affiliation: Department of Biochemistry, Hallym University College of Medicine, Chuncheon, Kangwon-Do, South Korea.
authors.forename: Chan-Young
authors.initials: CY
authors.lastname: Jeon
authors.forename: Hee-Jun
authors.initials: HJ
authors.lastname: Kim
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Morii
authors.forename: Nozomu
authors.initials: N
authors.lastname: Mori
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Settleman
authors.forename: Jae-Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Jaebong
authors.initials: J
authors.lastname: Kim
authors.forename: Sung-Chan
authors.initials: SC
authors.lastname: Kim
authors.forename: Jae-Bong
authors.initials: JB
authors.lastname: Park
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology; D016501:Neurites / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D016716:PC12 Cells / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C513040:Arhgap35 protein, rat; D020690:GTPase-Activating Proteins; D012097:Repressor Proteins; D016222:Fibroblast Growth Factor 2; D020742:rhoA GTP-Binding Protein