GENE 320 Lecture Notes - Lecture 19: Tumor Suppressor Gene, Red Meat, Ultraviolet
Document Summary
Signal transduction: initiates gene expression that propels cells out of g0 and back into the cell cycle. Cancer cells often have defects in signal transduction pathways. Occurs when dna or chromosomal damage is too severe to repair. Caspases: series of proteases responsisble for initiating apoptosis and digesting intracellular components. Dissolution of cell into small, spherical apoptotic bodies. Engu ing of apoptotic bodies by phagocytic cells p53 in the cell cycle. Has the ability to arrest the cell cycle at several phases w/o p53 a cell cannot arrest at cell cycle checkpoints or enter apoptosis. Dna damage/breaks presence of dna repair intermediates due to uv light. Most frequently mutated gene (50% of all cancers) present at low levels because it is always degraded. Increased levels due to increases in protein phosphorylation, acetylation, and other posttranslational modi cations. Dna damage leads to the phospharylation (activation) of p53 by protein kinases.
