title: Nuclear Rac1 regulates the bFGF-induced neurite outgrowth in PC12 cells.
abstract: Rac1 plays a key role in neurite outgrowth via reorganization of the actin cytoskeleton. The molecular mechanisms underlying Rac1-mediated actin dynamics in the cytosol and plasma membrane have been intensively studied, but the nuclear function of Rac1 in neurite outgrowth has not yet been addressed. Using subcellular fractionation and immunocytochemistry, we sought to explore the role of nuclear Rac1 in neurite outgrowth. bFGF, a strong agonist for neurite outgrowth in PC12 cells, stimulated the nuclear accumulation of an active form of Rac1. Rac1-PBR (Q) mutant, in which six basic residues in the polybasic region at the C-terminus were replaced by glutamine, didn't accumulate in the nucleus. In comparison with control cells, cells expressing this mutant form of Rac1 displayed a marked defect in extending neurites that was concomitant with reduced expression of MAP2 and MEK-1. These results suggest that Rac1 translocation to the nucleus functionally correlates with bFGF-induced neurite outgrowth.
authors.forename: Eung-Gook
authors.initials: EG
authors.lastname: Kim
authors.affiliation: Department of Biochemistry, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju 361-763, Korea eyshin@chungbuk.ac.kr.
authors.forename: Eun-Young
authors.initials: EY
authors.lastname: Shin
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002467:Cell Nucleus / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D005973:Glutamine / Q000235:genetics / Q000378:metabolism; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D016501:Neurites / Q000187:drug effects* / Q000378:metabolism; D016716:PC12 Cells; D051381:Rats; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: C489787:MAP2 protein, rat; D008869:Microtubule-Associated Proteins; D005973:Glutamine; D016222:Fibroblast Growth Factor 2; D048369:MAP Kinase Kinase 1; D020830:rac1 GTP-Binding Protein