LIFE 210 Lecture Notes - Cell Cycle, Microtubule-Associated Protein 2, Microtubule
Document Summary
Nucleation is the rate-limiting step in polymer formation. Formins nucleate the growth of straight, unbranched filaments. Remains associated with the growing plus end as the filament elongates. Proteins that bind to the free actin subunit modify filament elongation. Thymosin binds actin subunits and prevents incorporation in the filament. Stathmin binds to tubulin dimers and inhibits polymerization. Severing proteins regulate the length and kinetic behavior of actin filaments and microtubules. Proteins that bind along the sides of filaments can either stabilize or destabilize them. Different lengths of projecting domain bundles microtubules at different density. Cofilin forces the filament to twist more and become brittle. It also speeds up adp-actin dissociation from the minus end. Proteins that interact with filament ends can dramatically change filament dynamics. Large effect on filament dynamics with low protein amounts. Capping protein (capz) binds and stabilizes the actin filament plus end only minus end elongates or shrinks (slower dynamics)
