CYC7/YEL039C Summary Help

CYC7 BASIC INFORMATION

Standard Name CYC7
Systematic Name YEL039C
Feature Type ORF, Verified
Description Cytochrome c isoform 2, expressed under hypoxic conditions; electron carrier of the mitochondrial intermembrane space that transfers electrons from ubiquinone-cytochrome c oxidoreductase to cytochrome c oxidase during cellular respiration (1, 2 and see Summary Paragraph)
Name Description CYtochrome C
Gene Product Alias iso-2-cytochrome c 2
GO Annotations All CYC7 GO evidence and references
    View Computational GO annotations for CYC7
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
High-throughput
Mutant Phenotype All CYC7 Phenotype details and references
Large-scale survey
null
Interactions CYC7 All interactions details and references
15 total interaction(s) for 15 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 5
  • Affinity Capture-RNA: 1
  • Biochemical Activity: 2
  • PCA: 2
  • Protein-RNA: 1
  • Two-hybrid: 1
Genetic Interactions
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 1
Sequence Information
ChrV:79977 to 79636 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gbrowse
Genetic position: -27 cM
Last Update Coordinates: 1996-07-31 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates		 Chromosomal
Coordinates		 Most Recent Updates
Coordinates Sequence
CDS 1..342 79977..79636 1996-07-31 1996-07-31
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | UniProtKB
Primary SGDIDS000000765

CYC7 RESOURCES

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Expression Summary histogram

ADDITIONAL INFORMATION for CYC7

NOMENCLATURE CONFLICT NOTE

NameRelevanceDescription
CPR3Nomenclature conflictCYP3 has been used to refer to both CYC7/YEL039C, which encodes an isoform of cytochrome c, and CPR3/YML078W, which encodes a peptidyl-prolyl cis-trans isomerase.

SUMMARY PARAGRAPH for CYC7

CYC7 encodes an isoform, known as iso-2, of the electron carrier protein cytochrome c (3). Cytochrome c facilitates the penultimate and last steps of the mitochondrial respiratory chain via its covalently attached heme group: electron transfer from respiratory complex III to respiratory complex IV, and the final transfer of electrons to oxygen catalyzed by complex IV, cytochrome c oxidase. The cytochrome c genes were among the first yeast genes to be identified and have been studied extensively (4, 2, 5; reviewed in 6).

Transcription of CYC7 is repressed under aerobic conditions and induced at low oxygen concentrations (1, 7). Repression under aerobic conditions is mediated by the transcriptional repressor Rox1p (8); CYC7 is additionally subject to carbon catabolite repression (9). The CYC7 promoter contains a binding site for direct transcriptional activation by Hap1p in the presence of heme (10, 11, 12, 9).

Cyc7p comprises about 5% of the cytochrome c present in cells grown under aerobic, non-glucose repressing conditions, while the major isoform, Cyc1p, comprises 95% (4); the two isoforms are 84% identical to each other at the protein sequence level. Unlike iso-1 cytochrome c (Cyc1p), the Cyc7p apopotein (lacking its heme moiety) is not subject to degradation by the ubiquitin-dependent protein degradation pathway (13). Similar to Cyc1p, however, a single lysine residue of apo-Cyc7p is trimethylated in the cytoplasm by the action of the cytochrome c-specific methyltransferase Ctm1p (14, 15). Cyc7p is imported into the mitochondrial intermembrane space by a mechanism requiring the outer membrane translocase (TOM) complex (16, 17). Once in the intermembrane space, Cyc7p is covalently attached to heme in a reaction catalyzed by cytochrome c heme lyase (Cyc3p) (18).

Last updated: 2008-03-21

REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for CYC7]

1) Burke PV, et al.  (1997) Effects of oxygen concentration on the expression of cytochrome c and cytochrome c oxidase genes in yeast. J Biol Chem 272(23):14705-12
2) Downie JA, et al.  (1977) Structural gene for yeast iso-2-cytochrome c. J Mol Biol 113(2):369-84
3) Montgomery DL, et al.  (1980) Isolation and sequence of the gene for iso-2-cytochrome c in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 77(1):541-5
4) Sherman F, et al.  (1965) Genetic determination of iso-cytochromes c in yeast. J Mol Biol 13(1):21-39
5) Sherman F  (1990) Studies of yeast cytochrome c: how and why they started and why they continued. Genetics 125(1):9-12
6) Sherman F  (2005) The importance of mutation, then and now: studies with yeast cytochrome c. Mutat Res 589(1):1-16
7) Kwast KE, et al.  (1999) Oxygen sensing in yeast: evidence for the involvement of the respiratory chain in regulating the transcription of a subset of hypoxic genes. Proc Natl Acad Sci U S A 96(10):5446-51
8) Lowry CV and Zitomer RS  (1988) ROX1 encodes a heme-induced repression factor regulating ANB1 and CYC7 of Saccharomyces cerevisiae. Mol Cell Biol 8(11):4651-8
9) Prezant T, et al.  (1987) Organization of the regulatory region of the yeast CYC7 gene: multiple factors are involved in regulation. Mol Cell Biol 7(9):3252-9
10) Wright CF and Zitomer RS  (1984) A positive regulatory site and a negative regulatory site control the expression of the Saccharomyces cerevisiae CYC7 gene. Mol Cell Biol 4(10):2023-30
11) Verdiere J, et al.  (1985) Regulation of the expression of iso 2-cytochrome c gene in S. cerevisiae: cloning of the positive regulatory gene CYP1 and identification of the region of its target sequence on the structural gene CYP3. Mol Gen Genet 199(3):524-33
12) Fytlovich S, et al.  (1993) Evidence for an interaction between the CYP1(HAP1) activator and a cellular factor during heme-dependent transcriptional regulation in the yeast Saccharomyces cerevisiae. EMBO J 12(3):1209-18
13) Pearce DA and Sherman F  (1997) Differential ubiquitin-dependent degradation of the yeast apo-cytochrome c isozymes. J Biol Chem 272(50):31829-36
14) DeLange RJ, et al.  (1970) Identification and location of episilon-N-trimethyllysine in yeast cytochromes c. J Biol Chem 245(13):3325-7
15) Polevoda B, et al.  (2000) Cytochrome c methyltransferase, Ctm1p, of yeast. J Biol Chem 275(27):20508-13
16) Diekert K, et al.  (2001) Apocytochrome c requires the TOM complex for translocation across the mitochondrial outer membrane. EMBO J 20(20):5626-35
17) Wiedemann N, et al.  (2003) Biogenesis of yeast mitochondrial cytochrome c: a unique relationship to the TOM machinery. J Mol Biol 327(2):465-74
18) Wang X, et al.  (1996) Sequence requirements for mitochondrial import of yeast cytochrome c. J Biol Chem 271(12):6594-604