BIO 320 Lecture Notes - Lecture 22: Platelet-Derived Growth Factor, Lysosome, Growth Factor
Document Summary
Many signaling proteins contain domains that are folded into specific structures. These domains mediate specific associations between these signaling proteins and other proteins or membrane. Phosphotyrosine that is flanked by specific amino acid residues. Hence, different sh2 (and ptb) domains recognize phosphotyrosine in the context of different flanking amno acid sequences found on different rtks. nearby. Serine/threonine that is flanked by specific amino acid residues. Proteins with sh2 (or ptb) domains bind to phosphotyrosines on activated. Rtks or on phosphorylated docking/adaptor proteins that have docked onto activated rtks. This leads to the concentration of signaling proteins at specific sites on plasma membrane. An example is the pdgf receptor that regulates at least 3 downstream pathways. (functions like plcb, but is soluble protein before activation) For some rtks, tyrosine phosphorylation not only recruits additional signaling proteins. It also recruits proteins that down-regulate signaling, including a sh2-containing e3 (c-cbl) that ubiquitinates activated rtks.
