title: Carbon source affects PKA-dependent polarity of Neurospora crassa in a CRE-1-dependent and independent manner.
abstract: A defect in mcb, encoding the cAMP-dependent protein kinase A (PKA) regulatory subunit in Neurospora crassa, which confers an apolar growth phenotype, is accompanied by an increase in PKA activity levels. Both PKA and CRE-1 [a key carbon catabolite repression (CCR) regulator] mediate the cellular response to carbon-source availability. Inactivation of the cre-1 gene resulted in reduced growth rate, abnormal hyphal morphology and altered CCR. Both PKA and CRE-1 affected morphology in a carbon-dependent manner, as fructose suppressed the apolar morphology of the mcb strain and enabled faster growth of the Deltacre-1 mutant. An increase in cre-1 transcript abundance was observed in mcb and a reduction in PKA activity levels was measured in Deltacre-1. CRE-1 is involved in determining PKA-dependent polarity, as an mcb;Deltacre-1 strain displayed partial reestablishment of hyphal polarity. Taken together, our results demonstrate regulatory interactions between PKA and CRE-1 that affect cell polarity in a filamentous fungus.
authors.affiliation: Department of Plant Pathology and Microbiology, The Otto Warburg Minerva Center for Agricultural Biotechnology, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Carmit
authors.initials: C
authors.lastname: Ziv
authors.forename: Rena
authors.initials: R
authors.lastname: Gorovits
authors.forename: Oded
authors.initials: O
authors.lastname: Yarden
mesh_terms: D051698:Activating Transcription Factor 2 / Q000502:physiology*; D016764:Cell Polarity; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D005632:Fructose; D005656:Fungal Proteins / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D025301:Hyphae; D009492:Neurospora crassa / Q000502:physiology*; D021122:Protein Subunits / Q000235:genetics
chemical_list: D051698:Activating Transcription Factor 2; D005656:Fungal Proteins; D021122:Protein Subunits; D005632:Fructose; D017868:Cyclic AMP-Dependent Protein Kinases