Module 1: Figure tyrosine kinase-linked receptors
Tyrosine kinase-linked receptors.
There are 20 subfamilies of tyrosine kinase-linked receptors that resemble each other by having a single transmembrane domain that embeds the receptors in the plasma membrane. The receptors normally function as dimers. The insulin receptor pre-exists as a dimer, whereas the others dimerize when they bind their external stimuli. The cytoplasmic portion has the tyrosine kinase that functions in signal transduction. During activation by external stimuli, the receptors dimerize and then phosphorylate each other to provide phosphorylated binding sites that draw in various signalling components (e.g. see Module 1: Figure PDGFR activation). Reproduced from Handbook of Cell Signaling, Volume 1 (edited by R.A. Bradshaw and E.A. Dennis), Heldin, C.-H., Protein tyrosine kinase receptor signalling overview, pp. 391–396. Copyright (2003), with permission from Elsevier; see Heldin 2003.