BIOL 340 Lecture Notes - Lecture 6: Apoptosis, S Phase, Condensin
Document Summary
Cell cycle or cell-division cycle part 3 https://www. youtube. com/watch?v=eqjqha8hsj0. Oscillations in cdk activities factors influencing cdk activities. Four mechanisms for regulation of cdk activity in normal cells 1. Of cdk 2 by phosphorylation and dephosphorylation; 2. Synthesis role of retinoblastoma protein (prb); 4. Regulation of cdk at the time of dna damage role of prb and p53 separate. Extracellular signals such as growth factors and cytokines activate cdks. Cytokines - large group of proteins, peptides or glycoproteins which act as signaling molecules that mediate and regulate immunity. Cyclin and cki (cyclin dependent kinase inhibitory proteins) in g1/s and s phases are degraded by scf enzyme (ubiquitin ligase: m cyclin is degraded by apc (ubiquitin ligase) Reduced cyclin gene expression (decreased transcription of cyclin gene) Changes in transcription of cki genes: each step of cdk activation or inactivation marks a cell cycle transition. 4: these oscillations are the result of four mechanisms for regulating cdk activity.
