Receptors and Channels

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.

DDR1 (Epithelial discoidin domain-containing receptor 1, CD167a) is a receptor tyrosine kinase involved in cell-cell interactions and recognition. It is expressed in epithelial cells especially in the kidney, lung, gastrointestinal tract, and brain, and more highly in human breast, ovarian, esophageal, and pediatric brain tumors. Types I-VI collagen all induce the autophosphorylation of DDR1. Collagen regulates the interaction of DDR1 with KIBRA (WWC1), activating MAPK; these events are involved in mammary gland development.