LIFE 210 Lecture Notes - Centrosome, Leading Edge, Microtubule Organizing Center
Document Summary
Microtubule nucleation at the minus end by a protein complex containing -tubulin. Tubulin ring complex ( -turc) is a template that creates a microtubule with 13 protofilaments. Formed by -tubulin and accessory proteins that stabilize -tubulin. Microtubules emanate from the centrosome in animal cells. Microtubules are generally nucleated from the microtubule organizing center (mtoc) Most cells have a single mtoc, the centrosome, near the nucleus. Centrosome many copies of the -turc and a centrosome matrix. Cylindrical structures made of modified microtubules arranged at a right angle. The organization of microtubules with minus ends collected at the cell center is very robust. Experiment: a single centrosome placed into a square well along with tubulin subunits. Polymerization of microtubules push against the walls and stabilize the centrosome at the center of the well. Even without a centrosome a microtubule array can find the cell center and form a new. Actin nucleation at the minus end by the arp complex.
