IMM350H1 Lecture Notes - Lecture 4: Lck, Protein Kinase, Zap70
Document Summary
Surface receptors -> across plasma membrane -> intracellular signalling pathway -> nucleus or cytoskeleton. Lck phosphorylates tyrosine residues on cd3 and itams, allowing zap- 70 to bind: nucleus: cell division, differentiation, cell death, cytoskeleton: shape, size, motility. Protein kinases graft phosphates to target proteins (covalent link), reversible, generates sites to which other proteins can bind (signalling cascade: two types: tyrosine kinases & serine/threonine kinases. One class of transmembrane receptors has intrinsic kinase domains: ligand binding dimerize receptor, activating kinase to phosphorylate downstream substrates. Lck activates zap-70, which phosphorylates lat and slp-76, which bind phospholipase c- (plc- ) Pkc-0 activates carma which leads to nfkb activation. Dag recruits rasgrp which activates ras ras activates the. Fos, a component of the ap-1 transcription factor. Nfat, and ap-1 act to induce specific gene transcription, leading to cell proliferation and differentiation: kit (cd117) and flt3 (cd135) - developing lymphocytes.
