BMS 860 Lecture Notes - Lecture 9: Retinoblastoma Protein, Dna Ligase, Telomerase
26 Feb 2017
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Increased expression of anti-apoptotic regulators (e. g. bcl-2, bcl-x) Decreased expression of pro-apoptotic regulators (bad, bax, puma) One of kras effector pathways, 4 downstream pathways inositols (sugars) are bound to hydrophillic head groups in the plasma membrane, and the pathway works by phosphorylating inositols which results in a number of signaling cascades. Pi3 kinase phosphorylates pip2 to get pip3, which creates a docking site for cytoplasmic proteins (akt/pkb kinase) further phosphorylation by pdk1/2 activates akt/pkb. Active akt/pkb will induce changes that will increase survival of cell. Pten dephosphorylates akt/pkb, so it cannot bind or activate. Akt can inhibit apoptosis signals or phosphorylate mdm2, which degrades p53, and inhibits. In cancer, the pi3 kinase is overexpressed and pten function is lost apoptosis- cancer need to evade one of these pathways. Normal cells undergo replicative senescence senescence- biological aging at the cellular level. Unlike embryonic stem cells, adult somatic cells have a limited number of successive replicative cycles (hayflick limit)
