BIOL 150 Lecture Notes - Lecture 21: Cellular Differentiation, Sarcoma, Cytoskeleton
Document Summary
Biol 150 principles of molecular & cellular biology. We then turned to another major type of cell-cell signaling, which can have long-term effects: signling through receptor kinases (also called receptor tyrosine kinases, for the amino acid that is usually phosphorylated in these receptors). After being bound by a signal (ligand), these receptor proteins dimerize, i. e. two proteins come together, bound to each other by attraction to the ligand. The two proteins of the receptor activate each other by adding phosphate to each other, and then the activated protein binds to a small g-protein called ras (for. Rat sarcoma; it was first found in cells from a tumor in rats). When bound, ras exchanges gtp to replace the gdp bound to it and become activated. Activated ras begins a signaling cascade by binding to a kinase (kinase means the same thing as phosphorylase, an enzyme that uses atp to add phosphate groups to other proteins).
