title: Perturbation of cytoskeleton dynamics by the opposing effects of Rac1 and Rac1b.
abstract: Rac1, a ubiquitously expressed member of the Rho GTPase family, plays a pivotal role in the regulation of multiple cellular processes including cytoskeleton reorganization, cell growth, differentiation and motility. Here we show that the tumor-specific splice variant of Rac1, Rac1b, negatively regulates Rac1 activity. The expression of Rac1b in HeLa cells interferes with Rac1 activation by PDGF, leads to a reduction in membrane-bound Rac1 and promotes an increase in Rho activity. The antagonistic relationship between Rac1 and Rac1b perturbs the regulatory circuitry that controls actin cytoskeleton dynamics thereby leading to tumor-linked alterations in cell morphology and motility.
authors.affiliation: Department of Molecular Genetics and Microbiology; Stony Brook University; Stony Brook, NY USA.
authors.forename: Anjaruwee S
authors.initials: AS
authors.lastname: Nimnual
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Taylor
authors.forename: Marian
authors.initials: M
authors.lastname: Nyako
authors.forename: Hao-Hsuan
authors.initials: HH
authors.lastname: Jeng
authors.forename: Dafna
authors.initials: D
authors.lastname: Bar-Sagi