CIN4/YMR138W Summary Help

Standard Name CIN4 1, 2
Systematic Name YMR138W
Alias GTP1 , UGX1
Feature Type ORF, Verified
Description GTP-binding protein involved in beta-tubulin (Tub2p) folding; isolated as mutant with increased chromosome loss and sensitivity to benomyl; regulated by the GTPase-activating protein, Cin2p, the human retinitis pigmentosa 2 (RP2) homolog (1, 3, 4, 5 and see Summary Paragraph)
Name Description Chromosome INstability 1
Chromosomal Location
ChrXIII:545155 to 545730 | ORF Map | GBrowse
Genetic position: 86 cM
Gene Ontology Annotations All CIN4 GO evidence and references
  View Computational GO annotations for CIN4
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Regulators 3 genes
Classical genetics
Large-scale survey
110 total interaction(s) for 68 unique genes/features.
Physical Interactions
  • Affinity Capture-RNA: 2
  • Two-hybrid: 14

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 61
  • Positive Genetic: 3
  • Synthetic Growth Defect: 14
  • Synthetic Haploinsufficiency: 1
  • Synthetic Lethality: 13
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 191
Molecular Weight (Da) 22,066
Isoelectric Point (pI) 5.83
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIII:545155 to 545730 | ORF Map | GBrowse
Genetic position: 86 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..576 545155..545730 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 SGDIDS000004746

Microtubules are conserved cytoskeletal elements that form by the polymerization of alpha- and beta-tubulin heterodimers. The formation of polymerization-competent alpha- and beta-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 numerous organisms, including S.cerevisiae (reviewed in 6).

CIN4 is a non-essential gene that encodes a small GTPase of the ras superfamily, ADP-ribosylation factor (ARF) subfamily (4). The human homolog of CIN4, Arl2, has been shown to regulate the activity of the post-chaperonin tubulin folding pathway, in part by decreasing the affinity of cofactor D (Cin1p inS.cerevisiae) for native tubulin (4). By analogy, CIN4 may play a similar regulatory role in the yeast cofactor pathway, as it genetically interacts with several of the yeast tubulin cofactors (e.g. PAC2/cofactor E, CIN1/cofactor D, CIN2/cofactor C) (1, 7), and interacts in the two-hybrid assay with Cin2p/cofactor C (7).

CIN4 was isolated in a genetic screen for mutants that display super-sensitivity to benomyl, a microtubule-depolymerizing drug (1), and was independently isolated in a genetic screen for elevated chromosome loss (3). cin4 null mutants are cold-sensitive, show synthetic phenotypes in combination with tubulin mutants (1) and have defects in nuclear migration and nuclear fusion (or karyogamy) (3).

Last updated: 2003-08-28 Contact SGD

References cited on this page View Complete Literature Guide for CIN4
1) Stearns T, et al.  (1990) Yeast mutants sensitive to antimicrotubule drugs define three genes that affect microtubule function. Genetics 124(2):251-62
2) Stearns, T. and Botstein, D.  (1989) Personal Communication, Mortimer Map Edition 10
3) Hoyt MA, et al.  (1990) Chromosome instability mutants of Saccharomyces cerevisiae that are defective in microtubule-mediated processes. Mol Cell Biol 10(1):223-34
4) Bhamidipati A, et al.  (2000) ADP ribosylation factor-like protein 2 (Arl2) regulates the interaction of tubulin-folding cofactor D with native tubulin. J Cell Biol 149(5):1087-96
5) Veltel S, et al.  (2008) The retinitis pigmentosa 2 gene product is a GTPase-activating protein for Arf-like 3. Nat Struct Mol Biol 15(4):373-80
6) Lopez-Fanarraga M, et al.  (2001) Review: postchaperonin tubulin folding cofactors and their role in microtubule dynamics. J Struct Biol 135(2):219-29
7) Hoyt MA, et al.  (1997) Saccharomyces cerevisiae PAC2 functions with CIN1, 2 and 4 in a pathway leading to normal microtubule stability. Genetics 146(3):849-57