RAC1 — Neurospora crassa

Summary

NCU06454, also known as RAC1, CDC42, or NcRHO4, encodes a small GTPase of the Rho family on Neurospora crassa chromosome 3. The product possesses GTPase activity, binds GTP and GDP, and acts as a signaling adaptor and protein serine/threonine kinase activator. RAC1 is associated with tube development, chemotropism, bipolar cell growth, regulation of cell morphogenesis, and cell wall modification. It localizes to the hyphal tip polarisome, Spitzenkörper, exocytic vesicles, and the 1,3-beta-glucan synthase complex. The gene is linked to regulation of exocytosis, endocytic recycling, vesicle-mediated transport, and septin ring organization. Phenotypically, RAC1 is associated with abnormal filamentous growth, decreased cytokinesis rate, delayed sporulation, altered mating efficiency, and loss of osmotic stress resistance. Related genes in other species are associated with reduced virulence and loss of pathogenicity.