Regulation of maltose utilization in Saccharomyces cerevisiae by genes of the RAS/protein kinase A pathway.
In Saccharomyces cerevisiae maltose utilization requires a functional MAL locus, each composed of three genes: MALR (gene 3) encoding a regulatory protein, MALT (gene 1) encoding maltose permease and MALS (gene 2) encoding maltase. We show that constitutive activation of the RAS/protein kinase A pathway severely reduces growth of MAL1 strains on maltose. This may be a consequence of reduction in MALT mRNA, reduced Vmax and increased catabolite inactivation of the MALT-encoded maltose transporter in the MAL1 strain. Mutations in the GGS1/TPS1 gene, which restricts glucose influx and possibly affects signalling, relieve carbon catabolite repression on both maltase and maltose permease and reduce maltose permease inactivation.
Wanke
V
V
Dipartimento di Fisiologia e Biochimica Generali, Università degli Studi di Milano, Italy.
Vavassori
M
M
Thevelein
J M
JM
Tortora
P
P
Vanoni
M
M
D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D005800:Genes, Fungal; D007700:Kinetics; D008320:Maltose / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D000520:alpha-Glucosidases / Q000235:genetics / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism*
D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015534:Trans-Activators; D008320:Maltose; C021534:maltose permease; D017868:Cyclic AMP-Dependent Protein Kinases; D000520:alpha-Glucosidases; D018631:ras Proteins