BUL2/YML111W Summary Help

Standard Name BUL2 1
Systematic Name YML111W
Feature Type ORF, Verified
Description Component of the Rsp5p E3-ubiquitin ligase complex; involved in intracellular amino acid permease sorting, functions in heat shock element mediated gene expression, essential for growth in stress conditions; BUL2 has a paralog, BUL1, that arose from the whole genome duplication (1, 2, 3, 4, 5, 6 and see Summary Paragraph)
Name Description Binds Ubiquitin Ligase 1
Chromosomal Location
ChrXIII:46942 to 49704 | ORF Map | GBrowse
Gene Ontology Annotations All BUL2 GO evidence and references
  View Computational GO annotations for BUL2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 3 genes
Classical genetics
Large-scale survey
80 total interaction(s) for 54 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 15
  • Affinity Capture-RNA: 2
  • Biochemical Activity: 2
  • Two-hybrid: 14

Genetic Interactions
  • Dosage Rescue: 2
  • Negative Genetic: 26
  • Phenotypic Enhancement: 4
  • Phenotypic Suppression: 7
  • Positive Genetic: 1
  • Synthetic Growth Defect: 4
  • Synthetic Rescue: 3

Expression Summary
Length (a.a.) 920
Molecular Weight (Da) 104,785
Isoelectric Point (pI) 7.98
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIII:46942 to 49704 | ORF Map | GBrowse
Last Update Coordinates: 1996-07-31 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2763 46942..49704 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 SGDIDS000004579

Bul2p (Binds Ubiquitin Ligase) is a ubiquitin-binding protein that is a nonessential component of the Rsp5p E3-ubiquitin ligase complex (2). 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 (1). 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 (2). 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 (7).

A bul1 bul2 double disruptant is sensitive to temperature, salt, and carbon stress (1), 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 (2).

Last updated: 2005-10-10 Contact SGD

References cited on this page View Complete Literature Guide for BUL2
1) 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
2) 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
3) Springael JY, et al.  (2002) Yeast Npi3/Bro1 is involved in ubiquitin-dependent control of permease trafficking. FEBS Lett 517(1-3):103-9
4) Kaida D, et al.  (2003) Rsp5-Bul1/2 complex is necessary for the HSE-mediated gene expression in budding yeast. Biochem Biophys Res Commun 306(4):1037-41
5) Abe F and Iida H  (2003) Pressure-induced differential regulation of the two tryptophan permeases Tat1 and Tat2 by ubiquitin ligase Rsp5 and its binding proteins, Bul1 and Bul2. Mol Cell Biol 23(21):7566-84
6) 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
7) 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
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