Exam 4 cheat sheet-1 MANISH WITH CHRIS CRAP AT END

Exam 4 cheat sheet-1 MANISH WITH CHRIS CRAP AT END -...

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Cytoskeleton and Cell Behavior - myofibril , cylindrical= 1-2µm in diameter, made of sarcomeres , each about 2.2µm long -thin=actin(+end at Z-disc, capped -ends); thick=myosin (low processivity, 300 heads per filament, 5x per second -Z-disc=capZ and α-actinin; Nebulin =molecular ruler ; Titin =springlike, keeps myosin centered - myosin light chain kinase (MLCK) phosphorylates myosin (non-muscle) to activate it - tropomyosin stabilizes actin?, blocks myosin, Troponin I-T pulls tropomosin over site, Troponin C with Ca 2+ causes Troponin I to release tropomyosin - protrusion, attatchment, traction; - protrusive structures: filopodia -long thin bundle, lamellipodia -2D, and pseudopodia - short actin-gel; F:1D, L:2D, Ps:3D structures/projections; - protrusion : lemellipodia studied: actin does treadmilling; stationary (to substrate) network from ARPs (branch actin: phalloidin =fluorescent label), new filament=growing edge, cofilin disassembles lagging side, myosin II pulls filaments together - attatchment : highly adhesive=slower; weakly=faster; myosin helps push cell body forward; can help organize extra cellular matrix - Rho -protein family: monomeric GTPases ( Cdc42 , Rac , and Rho ): establish cell polarity; Cdc: actin polymerization>form filopeodia/µspikes, Rac: actin polym at periphery>sheet- like extensions/ruffles, Rho:bundle actin w/ myosin II into stress fibers and cluster integrins/associated proteins into focal contacts - WASp : Cdc - GTP enhances actin nucleation; Rac - G ..”and crosslinking for gel-forming protein filamin, inhibiting contraction; Rho-G ..:inhibits cofilin and inhibits phosphatases on MLC and increases myosin activity -neutrites : axons and dendrites collectively; MT are staggered to axon terminal, anterograde (to axon terminal) retro (back), -actin-based motility, neurofilaments (intermediate filamens) provide most important structural support in axon; actin=growth cone via filopodia, - Netrin : one of soluble proteins for attract/repel growth cones, regulated by Rac/Rho -transport: kinesin=out +, dynein -, over diffusion: 4.63days vs decades -dendrites: MT polarities mixed, axons: parallel and end-aligned Apoptosis - Endonucleosomes -break up DNA into tiny ladders - Phosohatidylserine -goes to outer leaflet to indicate apoptosis, recognized by Annexin V - Cytochrome C -found in intermembrane space of mitochondria; membrane potential loss (cell) Caspases – involved in inflammation or apoptosis use cysteine at active site to cleave specific aspartic acids; synthesized as inactive precursors (procaspases) and activated by proteolytic cleavage. Cleaved into 2, form heterodimer then tetramer and have amplifying cascade - initiator procaspaces =cleave and activate downstream executioner procaspases =target others executioners and target proteins -initiators have prodomain which has caspase recruitment domain (CARD) to form activation complexes with adaptor proteins. Activates intiators when near, and irreversible from there - extrinsic pathway -triggered by cell-surface
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Exam 4 cheat sheet-1 MANISH WITH CHRIS CRAP AT END -...

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