STE2/YFL026W Summary Help

Standard Name STE2
Systematic Name YFL026W
Feature Type ORF, Verified
Description Receptor for alpha-factor pheromone; seven transmembrane-domain GPCR that interacts with both pheromone and a heterotrimeric G protein to initiate the signaling response that leads to mating between haploid a and alpha cells (1, 2, 3 and see Summary Paragraph)
Name Description STErile
Chromosomal Location
ChrVI:82580 to 83875 | ORF Map | GBrowse
Genetic position: -37 cM
Gene Ontology Annotations All STE2 GO evidence and references
  View Computational GO annotations for STE2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 22 genes
Classical genetics
reduction of function
Large-scale survey
61 total interaction(s) for 40 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 7
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 4
  • Co-fractionation: 2
  • Co-localization: 1
  • Co-purification: 1
  • FRET: 2
  • PCA: 4
  • Protein-RNA: 1
  • Reconstituted Complex: 6
  • Two-hybrid: 4

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Lethality: 2
  • Dosage Rescue: 6
  • Phenotypic Enhancement: 1
  • Phenotypic Suppression: 5
  • Synthetic Growth Defect: 1
  • Synthetic Rescue: 10

Expression Summary
Length (a.a.) 431
Molecular Weight (Da) 47,849
Isoelectric Point (pI) 6.95
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrVI:82580 to 83875 | ORF Map | GBrowse
Genetic position: -37 cM
Last Update Coordinates: 2011-02-03 | Sequence: 2011-02-03
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1296 82580..83875 2011-02-03 2011-02-03
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 SGDIDS000001868

The first step in the mating pathway is the binding of mating pheromone to its receptor; the pheromone receptors are encoded by STE2 in MATa cells and STE3 in MATalpha cells. Both Ste2p and Ste3p are seven transmembrane domain G-protein coupled receptors that transmit their signals through a heterotrimeric G protein (2, 4). After binding alpha factor, Ste2p undergoes a conformational change, the associated G-alpha subunit (Gpa1p) exchanges GDP for GTP, and the beta (Ste4p)-gamma (Ste18p) complex is then released, activating downstream components of the pheromone response pathway (1, 5, 6).

The endocytosis and subsequent degradation of Ste2p has been successfully used as a system to better understand these general processes in yeast (7, 8). Endocytosis of Ste2p is not important for the pheromone response itself but is instead involved in the recovery from the pheromone signal (9). Some ubiquitinated Ste2p exists in the absence of alpha factor, and Ste2p is constitutively endocytosed and degraded in the vacuole; however, the Ste2-pheromone complex is hyperphosphorylated and endocytosed more rapidly (10, 11, 12, 13).

Last updated: 1999-10-18 Contact SGD

References cited on this page View Complete Literature Guide for STE2
1) Blumer KJ and Thorner J  (1990) Beta and gamma subunits of a yeast guanine nucleotide-binding protein are not essential for membrane association of the alpha subunit but are required for receptor coupling. Proc Natl Acad Sci U S A 87(11):4363-7
2) Burkholder AC and Hartwell LH  (1985) The yeast alpha-factor receptor: structural properties deduced from the sequence of the STE2 gene. Nucleic Acids Res 13(23):8463-75
3) Jenness DD, et al.  (1986) Binding of alpha-factor pheromone to Saccharomyces cerevisiae a cells: dissociation constant and number of binding sites. Mol Cell Biol 6(1):318-20
4) Hagen DC, et al.  (1986) Evidence the yeast STE3 gene encodes a receptor for the peptide pheromone a factor: gene sequence and implications for the structure of the presumed receptor. Proc Natl Acad Sci U S A 83(5):1418-22
5) Konopka JB and Fields S  (1992) The pheromone signal pathway in Saccharomyces cerevisiae. Antonie Van Leeuwenhoek 62(1-2):95-108
6) Herskowitz I  (1995) MAP kinase pathways in yeast: for mating and more. Cell 80(2):187-97
7) Kaiser CA, et al.  (1997) "Protein Secretion, Membrane Biogenesis, and Endocytosis." Pp. 91-228 in The Molecular and Cellular Biology of the Yeast Saccharomyces: Cell Cycle and Cell Biology, edited by Pringle JR, Broach JR and Jones EW. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press
8) Hicke L  (1997) Ubiquitin-dependent internalization and down-regulation of plasma membrane proteins. FASEB J 11(14):1215-26
9) Rohrer J, et al.  (1993) Identification of a novel sequence mediating regulated endocytosis of the G protein-coupled alpha-pheromone receptor in yeast. Mol Biol Cell 4(5):511-21
10) Konopka JB, et al.  (1988) The C-terminus of the S. cerevisiae alpha-pheromone receptor mediates an adaptive response to pheromone. Cell 54(5):609-20
11) Reneke JE, et al.  (1988) The carboxy-terminal segment of the yeast alpha-factor receptor is a regulatory domain. Cell 55(2):221-34
12) Jenness DD and Spatrick P  (1986) Down regulation of the alpha-factor pheromone receptor in S. cerevisiae. Cell 46(3):345-53
13) Hicke L and Riezman H  (1996) Ubiquitination of a yeast plasma membrane receptor signals its ligand-stimulated endocytosis. Cell 84(2):277-87