title: Ambient pH gene regulation in fungi: making connections.
abstract: Many fungi grow over a wide pH range and their gene expression is tailored to the environmental pH. In Aspergillus nidulans, the transcription factor PacC, an activator of genes expressed in alkaline conditions and a repressor of those expressed in acidic conditions, undergoes two processing proteolyses, the first being pH-signal dependent and the second proteasomal. Signal transduction involves a 'go-between' connecting two complexes, one of which comprises two plasma membrane proteins and an arrestin and the other comprises PacC, a cysteine protease, a scaffold and endosomal components. The Saccharomyces cerevisiae PacC orthologue, Rim101p, differs in that it does not undergo the second round of proteolysis and it functions directly as a repressor only. PacC/Rim101-mediated pH regulation is crucial to fungal pathogenicity.
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Cientificas, Ramiro de Maeztu, Madrid, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Peñalva
authors.forename: Joan
authors.initials: J
authors.lastname: Tilburn
authors.forename: Elaine
authors.initials: E
authors.lastname: Bignell
authors.forename: Herbert N
authors.initials: HN
authors.lastname: Arst
mesh_terms: D000818:Animals; D001233:Aspergillus nidulans / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D006863:Hydrogen-Ion Concentration; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D014157:Transcription Factors