RBL2/YOR265W Summary Help

Standard Name RBL2 1
Systematic Name YOR265W
Feature Type ORF, Verified
Description Protein involved in microtubule morphogenesis; required for protection from excess free beta-tubulin; proposed to be involved the folding of beta-tubulin; similar to mouse beta-tubulin cofactor A; protein abundance increases in response to DNA replication stress (1, 2, 3, 4 and see Summary Paragraph)
Name Description Rescues Beta-tubulin Lethality 1
Chromosomal Location
ChrXV:820454 to 820774 | ORF Map | GBrowse
Gene Ontology Annotations All RBL2 GO evidence and references
  View Computational GO annotations for RBL2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Regulators 8 genes
Large-scale survey
169 total interaction(s) for 93 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 3
  • Affinity Capture-RNA: 5
  • Affinity Capture-Western: 2
  • Co-crystal Structure: 2
  • Reconstituted Complex: 6
  • Two-hybrid: 7

Genetic Interactions
  • Dosage Lethality: 4
  • Dosage Rescue: 9
  • Negative Genetic: 88
  • Phenotypic Enhancement: 3
  • Positive Genetic: 5
  • Synthetic Growth Defect: 6
  • Synthetic Lethality: 28
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 106
Molecular Weight (Da) 12,379
Isoelectric Point (pI) 4.82
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXV:820454 to 820774 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..321 820454..820774 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 SGDIDS000005791

Microtubules are conserved cytoskeletal elements that form by the polymerization of alpha- and beta-tubulin heterodimers. The formation of polymerization-competent tubulin heterodimers requires that alpha-tubulin and beta-tubulin be properly folded. Specific cofactors are required for the folding of alpha- and beta-tubulin in vitro and homologs of these cofactors have been found in many organisms, including S.cerevisiae (reviewed in 5).

In S.cerevisiae, RBL2 is a non-essential gene that encodes the yeast structural and functional homolog of mouse beta-tubulin cofactor A 1. Cofactor A can complement Rbl2p function in vivo 1. Cofactor A is required in the post-chaperonin tubulin folding pathway in vitro, specifically for the folding of beta-tubulin 6. RBL2 was isolated in a genetic screen for genes that when overexpressed rescue the lethality caused by excess beta-tubulin (encoded by the TUB2 gene) 1. A high ratio of beta-tubulin to alpha-tubulin is lethal in S.cerevisiae, causing microtubule disassembly. RBL2 overexpression rescues beta-tubulin-associated lethality as efficiently as alpha-tubulin, and Rbl2p binds to beta-tubulin in vivo in a complex that excludes alpha-tubulin 1.

rbl2 null mutants are viable but supersensitive to benomyl, a microtubule depolymerizing drug 1. rbl2 null mutants are synthetically lethal in combination with specific alpha-tubulin mutants, most notably tub1-724, which creates an unstable heterodimer with beta-tubulin 1, 7, 8. In addition to acting in the beta-tubulin formation pathway, Rbl2p may also serve a protective function by sequestering free beta-tubulin monomers 1, 7, 8. However, excess RBL2 is lethal when the tubulin heterodimer is unstable, as overexpression of RBL2 in tub1-724, pac2/cofactorE, or cin1/cofactor D mutants causes lethality by depolymerization of microtubules 7.

Last updated: 2003-12-30 Contact SGD

References cited on this page View Complete Literature Guide for RBL2
1) Archer JE, et al.  (1995) Rbl2p, a yeast protein that binds to beta-tubulin and participates in microtubule function in vivo. Cell 82(3):425-34
2) Abruzzi KC, et al.  (2002) Protection from free beta-tubulin by the beta-tubulin binding protein Rbl2p. Mol Cell Biol 22(1):138-47
3) You L, et al.  (2004) Model for the yeast cofactor A-beta-tubulin complex based on computational docking and mutagensis. J Mol Biol 341(5):1343-54
4) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
5) Lopez-Fanarraga M, et al.  (2001) Review: postchaperonin tubulin folding cofactors and their role in microtubule dynamics. J Struct Biol 135(2):219-29
6) Tian G, et al.  (1996) Pathway leading to correctly folded beta-tubulin. Cell 86(2):287-96
7) Fleming JA, et al.  (2000) Function of tubulin binding proteins in vivo. Genetics 156(1):69-80
8) Archer JE, et al.  (1998) Formation and function of the Rbl2p-beta-tubulin complex. Mol Cell Biol 18(3):1757-62