The ubc2 gene of Ustilago maydis encodes a putative novel adaptor protein required for filamentous growth, pheromone response and virulence

Citation
Me. Mayorga et Se. Gold, The ubc2 gene of Ustilago maydis encodes a putative novel adaptor protein required for filamentous growth, pheromone response and virulence, MOL MICROB, 41(6), 2001, pp. 1365-1379
Citations number
60
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
MOLECULAR MICROBIOLOGY
ISSN journal
0950-382X → ACNP
Volume
41
Issue
6
Year of publication
2001
Pages
1365 - 1379
Database
ISI
SICI code
0950-382X(200109)41:6<1365:TUGOUM>2.0.ZU;2-J
Abstract
The Basidiomycete fungus Ustilago maydis causes corn smut disease and alter nates between a budding haploid saprophyte and a filamentous dikaryotic pat hogen. Previous work demonstrated that haploid adenylate cyclase (uac1) mut ants display a constitutively filamentous phenotype. Suppressor mutants of a uac1 disruption strain, named ubc for Ustilago bypass of cyclase, no long er require cAMP for the budding morphology. The ubc2 gene was isolated by c omplementation and is required for filamentous growth. The deduced amino ac id sequence encoded by ubc2 shows localized homology to Sterile Alpha Motif (SAM), Ras Association (RA) and Src homology 3 (SH3) protein-protein inter action domains. A K78E missense mutation within the SAM domain, revealed a genetic interaction between ubc2 and ubc4, a pheromone-responsive MAP kinas e kinase kinase, This indicates involvement of ubc2 in the pheromone-respon sive MAP kinase cascade and ubc2 is required for pheromone-responsive morph ogenesis. The ubc2 gene is a critical virulence factor. Thus, ubc2 encodes a putative novel adaptor protein that may act directly upstream of the pher omone-responsive MAP kinase cascade in U. maydis.