Premium
The ubc2 gene of Ustilago maydis encodes a putative novel adaptor protein required for filamentous growth, pheromone response and virulence
Author(s) -
Mayorga María E.,
Gold Scott E.
Publication year - 2001
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2001.02606.x
Subject(s) - ustilago , biology , virulence , signal transducing adaptor protein , gene , genetics , pheromone
The Basidiomycete fungus Ustilago maydis causes corn smut disease and alternates between a budding haploid saprophyte and a filamentous dikaryotic pathogen. Previous work demonstrated that haploid adenylate cyclase ( uac1 ) mutants display a constitutively filamentous phenotype. Suppressor mutants of a uac1 disruption strain, named ubc for U stilago b ypass of c yclase, no longer require cAMP for the budding morphology. The ubc2 gene was isolated by complementation and is required for filamentous growth. The deduced amino acid sequence encoded by ubc2 shows localized homology to Sterile Alpha Motif (SAM), Ras Association (RA) and Src homology 3 (SH3) protein–protein interaction domains. A K78E missense mutation within the SAM domain, revealed a genetic interaction between ubc2 and ubc4 , a pheromone‐responsive MAP kinase kinase kinase. This indicates involvement of ubc2 in the pheromone‐responsive MAP kinase cascade and ubc2 is required for pheromone‐responsive morphogenesis. The ubc2 gene is a critical virulence factor. Thus, ubc2 encodes a putative novel adaptor protein that may act directly upstream of the pheromone‐responsive MAP kinase cascade in U. maydis .