Member database | PROSITE patterns |
PROSITE patterns type | conserved site |
Short name | RECEPTOR_TYR_KIN_II |
Description
A number of growth factors stimulate mitogenesis by interacting with a family
of cell surface receptors which possess an intrinsic, ligand-sensitive,
protein tyrosine kinase activity
[1]. These receptor tyrosine kinases (RTK)
all share the same topology: an extracellular ligand-binding domain, a single
transmembrane region and a cytoplasmic kinase domain. However they can be
classified into at least five groups. The prototype for class II RTK's is the
insulin receptor, a heterotetramer of two alpha and two beta chains linked by
disulfide bonds. The alpha and beta chains are cleavage products of a
precursor molecule. The alpha chain contains the ligand binding site, the beta
chain transverses the membrane and contains the tyrosine protein kinase
domain. The receptors currently known to belong to class II are:
- Insulin receptor from vertebrates.
- Insulin growth factor I receptor from mammals.
- Insulin receptor-related receptor (IRR), which is most probably a receptor
for a peptide belonging to the insulin family.
- Insects insulin-like receptors.
- Molluscan insulin-related peptide(s) receptor (MIP-R).
- Insulin-like peptide receptor from Branchiostoma lanceolatum.
- The Drosophila developmental protein sevenless, a putative receptor for
positional information required for the formation of the R7 photoreceptor
cells.
- The trk family of receptors (NTRK1, NTRK2 and NTRK3), which are high
affinity receptors for nerve growth factor and related neurotrophic factors
(BDNF and NT-3).
And the following uncharacterized receptors:
- ROS.
- LTK (TYK1).
- EDDR1 (cak, TRKE, RTK6).
- NTRK3 (Tyro10, TKT).
- A sponge putative receptor tyrosine kinase.
While only the insulin and the insulin growth factor I receptors are known to
exist in the tetrameric conformation specific to class II RTK's, all the above
proteins share extensive homologies in their kinase domain, especially around
the putative site of autophosphorylation. Hence, we developed a signature
pattern for this class of RTK's, which includes the tyrosine residue, itself
probably autophosphorylated.
References
1.Growth factor receptor tyrosine kinases. Yarden Y, Ullrich A. Annu. Rev. Biochem. 57, 443-78, (1988). View articlePMID: 3052279