title: pH-regulated expression of the acid and alkaline extracellular proteases of Yarrowia lipolytica.
abstract: The pH-regulated expression of the acid (AXP) and alkaline (AEP) extracellular proteases of the yeast Yarrowia lipolytica 148 was analysed. Expression in batch and continuous cultures was determined at the mRNA level by Northern blotting, and at the enzyme level by enzyme assays and Western blotting. Culture pH regulated AEP and AXP expression predominantly at the level of mRNA content. Highest levels of AEP mRNA were detected at pH 6.5 whereas highest levels of AXP mRNA were detected at pH 5.5. At pH values either side of these maxima AEP and AXP expression were progressively down-regulated. For both enzymes, the variation in mRNA levels with culture pH occurred progressively rather than by discrete steps. AXP expression did not occur above pH 7.0. Some degree of AEP expression occurred at all pH values tested in two unrelated strains of Y. lipolytica.
authors.affiliation: Schools of Biochemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Glover
authors.affiliation: Schools of Biochemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: Robert K
authors.initials: RK
authors.lastname: McEwen
authors.affiliation: Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: Colin R
authors.initials: CR
authors.lastname: Thomas
authors.affiliation: Schools of Biochemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Young
mesh_terms: D000199:Actins / Q000235:genetics; D016282:Aspartic Acid Endopeptidases / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D005656:Fungal Proteins; D015870:Gene Expression; D005800:Genes, Fungal; D006863:Hydrogen-Ion Concentration; D016133:Polymerase Chain Reaction; D011770:Pyruvate Kinase / Q000235:genetics; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D004718:Saccharomycetales / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D012697:Serine Endopeptidases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D000199:Actins; D017931:DNA Primers; D005656:Fungal Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D011770:Pyruvate Kinase; D012697:Serine Endopeptidases; C067468:Yarrowia lipolytica alkaline extracellular protease; C103006:AXP protein, Yarrowia lipolytica; D016282:Aspartic Acid Endopeptidases