cAMP regulates morphogenesis in the fungal pathogen Ustilago maydis.
The fungal pathogen Ustilago maydis exhibits a dimorphic switch from budding to filamentous growth in response to mating interactions and environmental conditions. We have found that disruption of the uac1 gene, encoding adenylate cyclase, results in a constitutively filamentous phenotype. Budding is restored to the uac1 mutant upon growth in the presence of cAMP or by extragenic suppression because of a mutation in the ubc1 gene. The ubc1 gene encodes a type II regulatory subunit of cAMP-dependent protein kinase (PKA); defects in this gene attenuate the filamentous growth that normally occurs in response to mating and exposure to air. Growth of wild-type cells in cAMP and mutation of the ubc1 gene also cause defects in the separation of mother and daughter cells (cytokinesis) and alter bud site selection. These results indicate a key role for cAMP and PKA in morphogenesis in U. maydis; this role may be common among dimorphic fungal pathogens.
Gold
S
S
Department of Microbiology, University of British Columbia, Vancouver, Canada.
Duncan
G
G
Barrett
K
K
Kronstad
J
J
D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000242:Cyclic AMP / Q000502:physiology*; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D004271:DNA, Fungal / Q000378:metabolism; D015723:Gene Library; D005800:Genes, Fungal; D005838:Genotype; D008954:Models, Biological; D008969:Molecular Sequence Data; D009024:Morphogenesis; D016366:Open Reading Frames; D010641:Phenotype; D012098:Reproduction; D017386:Sequence Homology, Amino Acid; D014588:Ustilago / Q000166:cytology / Q000235:genetics / Q000254:growth & development*
D004271:DNA, Fungal; D000242:Cyclic AMP; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D000262:Adenylyl Cyclases