Guanyl nucleotide exchange factor Sql2 and Ras2 regulate filamentous growth in Ustilago maydis.

ABSTRACT: The cyclic AMP (cAMP)-signaling pathway regulates cell morphology and plays a crucial role during pathogenic development of the plant-pathogenic fungus Ustilago maydis. Strains lacking components of this signaling pathway, such as the Galpha-subunit Gpa3 or the adenylyl cyclase Uac1, are nonpathogenic and grow filamentously. On the other hand, strains exhibiting an activated cAMP pathway due to a dominant-active allele of gpa3 display a glossy colony phenotype and are unable to proliferate in plant tumors. Here we present the identification of sql2 as a suppressor of the glossy colony phenotype of a gpa3(Q206L) strain. sql2 encodes a protein with similarity to CDC25-like guanine nucleotide exchange factors, which are known to act on Ras proteins. Overexpression of sql2 leads to filamentous

SUBMITTER: Muller P 

PROVIDER: S-EPMC161447 | biostudies-literature | 2003 Jun

REPOSITORIES: biostudies-literature