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Unformatted text preview: o The plus-end is free to grow and shrink Dynamic instability : MTs cycle between catastrophe (rapid depolymerization) and rescue (restarted polymerization) Microtubule-associated motors : kinesins, dyneins Both are ATPases and are used to traffic vesicles and other cargo along MTs Kinesins mostly move towards the plus-end, while dyneins move towards the minus-end Drugs that affect MTs: Taxol stabilizes the cap of GTP-bound -tubulin and promotes MT growth/stability Colchicine promotes GTPase activity of -tubulin, encouraging MT instability and depolymerization MAPs (Microtubule-associated proteins): Kinesin-13 binds free dimers (reducing their concentration) and promotes GTP hydrolysis at the plus-end destabilizing Stathmin/Op18 bends and destabilizes the plus-end Katanin and Spastin sever MTs (promoting depolymerization: severed end has no GTP cap) Lattice- & end-binding MAPs stabilize microtubules...
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- Fall '09
- cell biology