VMA3/YEL027W Summary Help

Standard Name VMA3 1, 2
Systematic Name YEL027W
Alias CLS7 , GEF2 , CUP5 3
Feature Type ORF, Verified
Description Proteolipid subunit c of the V0 domain of vacuolar H(+)-ATPase; dicyclohexylcarbodiimide binding subunit; required for vacuolar acidification and important for copper and iron metal ion homeostasis (4, 5 and see Summary Paragraph)
Name Description Vacuolar Membrane Atpase
Chromosomal Location
ChrV:100769 to 101251 | ORF Map | GBrowse
Genetic position: -18 cM
Gene Ontology Annotations All VMA3 GO evidence and references
  View Computational GO annotations for VMA3
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 2 genes
Classical genetics
Large-scale survey
200 total interaction(s) for 178 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 3
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 6
  • Co-fractionation: 1
  • Co-purification: 1
  • PCA: 14
  • Protein-peptide: 1
  • Reconstituted Complex: 2

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 100
  • Phenotypic Enhancement: 2
  • Phenotypic Suppression: 2
  • Positive Genetic: 33
  • Synthetic Growth Defect: 12
  • Synthetic Haploinsufficiency: 11
  • Synthetic Lethality: 5
  • Synthetic Rescue: 3

Expression Summary
Length (a.a.) 160
Molecular Weight (Da) 16,350
Isoelectric Point (pI) 7.93
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrV:100769 to 101251 | ORF Map | GBrowse
Genetic position: -18 cM
Last Update Coordinates: 1996-07-31 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..483 100769..101251 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 | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000000753

VMA3 encodes the c subunit of the yeast V-ATPase V0 domain (1). Vacuolar (H )-ATPases (V-ATPases) are ATP-dependent proton pumps that acidify intracellular vacuolar compartments. Vacuolar acidification is important for many cellular processes, including endocytosis, targeting of newly synthesized lysosomal enzymes, and other molecular targeting processes. The V-ATPase consists of two separable domains. The V1 domain has eight known subunits, is peripherally associated with the vacuolar membrane, and catalyzes ATP hydrolysis. The V0 domain is an integral membrane structure of five subunits, and transports protons across the membrane. The structure, function, and assembly of V-ATPases are reviewed in references 6, 7, 8 and 9.

The V0 c, c' (Vma11p), and c'' (Vma16p) subunits are highly hydrophobic integral membrane proteolipids, and have similar amino acid sequences; all three are required for V-ATPase activity (6, 9). Vma3p is also involved in copper and iron homeostasis (5, 4). The vma3 null mutant is viable but lacks vacuolar (H )-ATPase activity, and is defective in vacuolar acidification, vacuole biogenesis, vacuolar protein targeting, and endocytosis (1). The a and b V0 subunits do not assemble in the absence of Vma3p (1).

V-ATPases have been identified in numerous eukaryotes; c subunit homologs have been identified in Drosophila, Manduca sexta, and Nephrops norvegicus, and the Drosophila and Nephrops genes can rescue the vma3 null phenotype (10, 11).

Last updated: 2000-05-18 Contact SGD

References cited on this page View Complete Literature Guide for VMA3
1) Umemoto N, et al.  (1990) Roles of the VMA3 gene product, subunit c of the vacuolar membrane H(+)-ATPase on vacuolar acidification and protein transport. A study with VMA3-disrupted mutants of Saccharomyces cerevisiae. J Biol Chem 265(30):18447-53
2) Nelson H and Nelson N  (1989) The progenitor of ATP synthases was closely related to the current vacuolar H+-ATPase. FEBS Lett 247(1):147-53
3) Welch, J.W. and Fogel, S.  (1985) Personal Communication, Mortimer Map Edition 9
4) Szczypka MS, et al.  (1997) Saccharomyces cerevisiae mutants altered in vacuole function are defective in copper detoxification and iron-responsive gene transcription. Yeast 13(15):1423-35
5) Eide DJ, et al.  (1993) The vacuolar H(+)-ATPase of Saccharomyces cerevisiae is required for efficient copper detoxification, mitochondrial function, and iron metabolism. Mol Gen Genet 241(3-4):447-56
6) Forgac M  (1999) Structure and properties of the vacuolar (H+)-ATPases. J Biol Chem 274(19):12951-4
7) Graham LA and Stevens TH  (1999) Assembly of the yeast vacuolar proton-translocating ATPase. J Bioenerg Biomembr 31(1):39-47
8) Kane PM  (1999) Biosynthesis and regulation of the yeast vacuolar H+-ATPase. J Bioenerg Biomembr 31(1):49-56
9) Stevens TH and Forgac M  (1997) Structure, function and regulation of the vacuolar (H+)-ATPase. Annu Rev Cell Dev Biol 13:779-808
10) Finbow ME, et al.  (1994) Evidence that the 16 kDa proteolipid (subunit c) of the vacuolar H(+)-ATPase and ductin from gap junctions are the same polypeptide in Drosophila and Manduca: molecular cloning of the Vha16k gene from Drosophila. J Cell Sci 107 ( Pt 7):1817-24
11) Harrison MA, et al.  (1994) Functional properties of a hybrid vacuolar H(+)-ATPase in Saccharomyces cells expressing the Nephrops 16-kDa proteolipid. Eur J Biochem 221(1):111-20