GAL80/YML051W Summary Help

Standard Name GAL80 1
Systematic Name YML051W
Feature Type ORF, Verified
Description Transcriptional regulator involved in the repression of GAL genes; involved in the repression of GAL genes in the absence of galactose; inhibits transcriptional activation by Gal4p; inhibition relieved by Gal3p or Gal1p binding (2 and see Summary Paragraph)
Name Description GALactose metabolism
Chromosomal Location
ChrXIII:171594 to 172901 | ORF Map | GBrowse
Genetic position: -33 cM
Gene Ontology Annotations All GAL80 GO evidence and references
  View Computational GO annotations for GAL80
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 3 genes
Classical genetics
dominant negative
Large-scale survey
181 total interaction(s) for 115 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 1
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 11
  • Co-crystal Structure: 3
  • Co-localization: 1
  • Co-purification: 3
  • FRET: 1
  • PCA: 7
  • Protein-peptide: 5
  • Reconstituted Complex: 15
  • Two-hybrid: 39

Genetic Interactions
  • Dosage Growth Defect: 2
  • Dosage Lethality: 1
  • Dosage Rescue: 1
  • Negative Genetic: 53
  • Phenotypic Enhancement: 4
  • Phenotypic Suppression: 2
  • Positive Genetic: 16
  • Synthetic Growth Defect: 2
  • Synthetic Rescue: 13

Expression Summary
Length (a.a.) 435
Molecular Weight (Da) 48,323
Isoelectric Point (pI) 8.16
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIII:171594 to 172901 | ORF Map | GBrowse
Genetic position: -33 cM
Last Update Coordinates: 1996-07-31 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1308 171594..172901 1996-07-31 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000004515

GAL80 encodes a transcriptional repressor involved in transcriptional regulation in response to galactose (2). In conjunction with Gal4p and Gal3p, Gal80p coordinately regulates the expression of genes containing a GAL upstream activation site in their promoter (UAS-GAL), which includes the GAL metabolic genes GAL1, GAL10, GAL2, and GAL7 (reviewed in 3). Cells null for gal80 constitutively express GAL genes, even in non-inducing media (4).

In the absence of galactose, Gal80p binds, as a dimer, to the transcription factor Gal4p, thus preventing Gal4p from recruiting other factors of the Pol II transcription machinery (5). In the presence of galactose,Gal3p interacts with Gal80p, which relieves inhibition of Gal4p and results in GAL gene expression (6). Gal80p interacts with Gal3p as a monomer and only in the presence of both galactose and ATP (2). In the absence of Gal3p, the Gal1p galactokinase can interact with and partially inhibit Gal80p function (2, 7).

GAL80 transcription is also regulated by the Gal3p/Gal80p/Gal4p feedback mechanism that regulates the other GAL genes. However, unlike expression of the GAL structural genes, which is tightly controlled because of the presence of multiple UAS-GALs in their promoters, GAL80 has high basal levels of transcription due to the presence of only a single UAS-GAL in its promoter (8).

Last updated: 2013-05-23 Contact SGD

References cited on this page View Complete Literature Guide for GAL80
1) Hopper JE and Rowe LB  (1978) Molecular expression and regulation of the galactose pathway genes in Saccharomyces cerevisiae. Distinct messenger RNAs specified by the Gali and Gal7 genes in the Gal7-Gal10-Gal1 cluster. J Biol Chem 253(20):7566-9
2) Timson DJ, et al.  (2002) Gal3p and Gal1p interact with the transcriptional repressor Gal80p to form a complex of 1:1 stoichiometry. Biochem J 363(Pt 3):515-20
3) Lohr D, et al.  (1995) Transcriptional regulation in the yeast GAL gene family: a complex genetic network. FASEB J 9(9):777-87
4) Torchia TE, et al.  (1984) Disruption of regulatory gene GAL80 in Saccharomyces cerevisiae: effects on carbon-controlled regulation of the galactose/melibiose pathway genes. Mol Cell Biol 4(8):1521-7
5) Pilauri V, et al.  (2005) Gal80 dimerization and the yeast GAL gene switch. Genetics 169(4):1903-14
6) Peng G and Hopper JE  (2002) Gene activation by interaction of an inhibitor with a cytoplasmic signaling protein. Proc Natl Acad Sci U S A 99(13):8548-53
7) Bhat PJ and Hopper JE  (1992) Overproduction of the GAL1 or GAL3 protein causes galactose-independent activation of the GAL4 protein: evidence for a new model of induction for the yeast GAL/MEL regulon. Mol Cell Biol 12(6):2701-7
8) Melcher K and Xu HE  (2001) Gal80-Gal80 interaction on adjacent Gal4p binding sites is required for complete GAL gene repression. EMBO J 20(4):841-51