Receptors and Channels

Epidermal growth factor receptor (EGFR) is a receptor for EGF and for various members of the EGF family such as TGF-alpha, amphiregulin, betacellulin, heparin-binding EGF-like growth factor, GP30 and vaccinia virus growth factor. EGFR is involved in the control of cell growth and differentation. Binding of EGF to the receptor leads to dimerization, internalization of the EGF-receptor complex, induction of the tyrosine kinase activity, stimulation of cell DNA synthesis and cell proliferation.

Proto-oncogene tyrosine-protein kinase receptor ret (C-ret) is a tyrosine kinase receptor for DOK2, 4 and 5 important in development. Defects in C-ret are a cause of pheochromocytoma, thyroid carcinoma, neoplasia and neural crest development disorders.

Merlin (NF2) acts as a membrane stabilizing protein and may inhibit PI3 kinase by binding to CENTG1. Defects in NF2 are the cause of neurofibromatosis 2 and schwannnomatosis (neuromas).

Upon ligand binding, BMPR1A forms a receptor complex consisting of two type II and two type I transmembrane Ser/Thr kinases. The type I receptors are activated by the type II receptors by using a phosphorylation mechanism, and subsequently bind SMAD transcriptional regulators. Defects in BMPR1A are the cause of juvenile polyposis syndrome, Cowden disease and hereditary mixed polyposis syndrome 2, which lead to gastrointestinal, breast, thyroid, endometrial and colon cancers.

RYK is a potential growth factor receptor protein tyrosine kinase.