BUL1/YMR275C Summary Help

Standard Name BUL1 1
Systematic Name YMR275C
Alias DAG1 , RDS1 , SMM2
Feature Type ORF, Verified
Description Ubiquitin-binding component of the Rsp5p E3-ubiquitin ligase complex; disruption causes temperature-sensitive growth, overexpression causes missorting of amino acid permeases; BUL1 has a paralog, BUL2, that arose from the whole genome duplication (2, 3, 4 and see Summary Paragraph)
Name Description Binds Ubiquitin Ligase 1
Chromosomal Location
ChrXIII:818581 to 815651 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All BUL1 GO evidence and references
  View Computational GO annotations for BUL1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 11 genes
Classical genetics
Large-scale survey
178 total interaction(s) for 118 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 13
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 7
  • Biochemical Activity: 3
  • PCA: 1
  • Reconstituted Complex: 2
  • Two-hybrid: 15

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Lethality: 2
  • Dosage Rescue: 7
  • Negative Genetic: 78
  • Phenotypic Enhancement: 4
  • Phenotypic Suppression: 8
  • Positive Genetic: 13
  • Synthetic Growth Defect: 9
  • Synthetic Lethality: 1
  • Synthetic Rescue: 13

Expression Summary
Length (a.a.) 976
Molecular Weight (Da) 109,173
Isoelectric Point (pI) 8.98
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIII:818581 to 815651 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2931 818581..815651 2011-02-03 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 SGDIDS000004888

Bul1p (Binds Ubiquitin Ligase) is a ubiquitin-binding protein that is a nonessential component of the Rsp5p E3-ubiquitin ligase complex (3), and has been implicated in controlling aspects of post-Golgi endosomal-vacuolar protein sorting (5). BUL2 is a functional homolog of BUL1, and each Bul protein has a putative PY-motif that has been predicted to interact with one of three WW-domains of the Rsp5p ubiquitin ligase (2). Bul1p and Bul2p, together with Rsp5p, generate a polyubiquitin signal on Gap1p, the general amino acid permease, that specifies its intracellular targeting to the vacuole (3). In addition, Bul1p and Bul2p are required for GLN3 activation under poor nitrogen conditions, and antagonistically control GLN3-dependent transcription in concert with Npr1p, a protein kinase that controls post-Golgi sorting of amino acid permeases, suggesting a role for regulated ubiquitination in the control of nutrient-responsive transcription (6).

Mutations in BUL1 render cells resistant to isoflurane and other volatile anesthetics (7), and disruption of BUL1 causes temperature-sensitive growth which can be partially suppressed by high dosage of ubiquitin-encoding UBI1 (1). A bul1 bul2 double disruptant is sensitive to temperature, salt, and carbon stress (2), and the temperature sensitivity can be suppressed by multiple copies of kinase-encoding MCK1, and also by mutations in genes encoding the Rog1p lipase and Nat5p acetyltransferase (8). Overexpression of Bul1p or Bul2p causes Gap1p to be sorted to the vacuole, whereas the double mutant bul1 bul2 has the inverse phenotype, causing Gap1p to be delivered to the plasma membrane more efficiently than in wild-type cells. Further, bul1 bul2 can reverse the effect of mutations in the Lst4p protein transporter that normally prevent Gap1p from reaching the plasma membrane (3).

Last updated: 2004-12-01 Contact SGD

References cited on this page View Complete Literature Guide for BUL1
1) Yashiroda H, et al.  (1996) Bul1, a new protein that binds to the Rsp5 ubiquitin ligase in Saccharomyces cerevisiae. Mol Cell Biol 16(7):3255-63
2) Yashiroda H, et al.  (1998) The PY-motif of Bul1 protein is essential for growth of Saccharomyces cerevisiae under various stress conditions. Gene 225(1-2):39-46
3) Helliwell SB, et al.  (2001) Components of a ubiquitin ligase complex specify polyubiquitination and intracellular trafficking of the general amino acid permease. J Cell Biol 153(4):649-62
4) Byrne KP and Wolfe KH  (2005) The Yeast Gene Order Browser: combining curated homology and syntenic context reveals gene fate in polyploid species. Genome Res 15(10):1456-61
5) Forsberg H, et al.  (2001) Suppressors of ssy1 and ptr3 null mutations define novel amino acid sensor-independent genes in Saccharomyces cerevisiae. Genetics 158(3):973-88
6) Crespo JL, et al.  (2004) NPR1 kinase and RSP5-BUL1/2 ubiquitin ligase control GLN3-dependent transcription in Saccharomyces cerevisiae. J Biol Chem 279(36):37512-7
7) Wolfe D, et al.  (1999) Ubiquitin metabolism affects cellular response to volatile anesthetics in yeast. Mol Cell Biol 19(12):8254-62
8) Andoh T, et al.  (2000) Yeast glycogen synthase kinase 3 is involved in protein degradation in cooperation with Bul1, Bul2, and Rsp5. Mol Cell Biol 20(18):6712-20