Member database | PROSITE profiles |
PROSITE profiles type | domain |
Short name | G_PROTEIN_RECEP_F2_4 |
Description
A number of peptide hormones bind to G-protein coupled receptors that, while
structurally similar to family 1 of G-protein coupled receptors (R7G), do not show any similarity at the level of their sequence, thus
representing a new family whose current known members
[2] are listed below:
- Calcitonin receptor.
- Calcitonin gene-related peptide receptor.
- Corticotropin releasing factor receptor types 1 and 2.
- Gastric inhibitory polypeptide receptor.
- Glucagon receptor.
- Glucagon-like peptide 1 receptor.
- Growth hormone-releasing hormone receptor.
- Parathyroid hormone / parathyroid hormone-related peptide types 1 and 2.
- Pituitary adenylate cyclase activating polypeptide receptor.
- Secretin receptor.
- Vasoactive intestinal peptide receptor types 1 and 2.
- Insects diuretic hormone receptor.
In addition to the above characterized receptors, this family also includes:
- Caenorhabditis elegans putative receptor C13B9.4.
- Caenorhabditis elegans putative receptor ZK643.3.
- Leucocyte antigen CD97, a protein that contains, in its N-terminal section,
3 EGF-like domains.
- Cell surface glycoprotein EMR1, a protein that contains, in its N-terminal
section, 6 to 7 EGF-like domains.
All the characterized receptors are coupled to G-proteins which activate both
adenylyl cyclase and the phosphatidylinositol-calcium pathway.
Like family 1 R7G they seem to contain seven transmembrane regions. Their
N-terminus is probably located on the extracellular side of the membrane and
potentially glycosylated, while their C-terminus is probably cytoplasmic.
Every receptor gene in this family is encoded on multiple exons, and several
of these genes are alternatively spliced to yield functionally distinct
products.
Family two G protein coupled receptors contain a long conserved region in
their N terminal extracellular part which allow the binding of large peptidic
ligand such as glucagon, secretin, VIP and PACAP
[1]. This region contains
five conserved cysteines residues which could be involved in disulfide bonds;
we have developed a pattern in the region that spans the first three
cysteines. We also developed a profile that covers the whole extracellular
domain.
One of the most highly conserved regions spans the C-terminal part of the last
transmembrane region and the beginning of the adjacent intracellular region.
We have used this region as a second signature pattern. We also developed a
profile that spans the seven transmembrane regions.
References
1.Molecular tinkering of G protein-coupled receptors: an evolutionary success. Bockaert J, Pin JP. EMBO J. 18, 1723-9, (1999). View articlePMID: 10202136
2.Structure of the human CD97 gene: exon shuffling has generated a new type of seven-span transmembrane molecule related to the secretin receptor superfamily. Hamann J, Hartmann E, van Lier RA. Genomics 32, 144-7, (1996). View articlePMID: 8786105