BIOL 1090 Lecture Notes - Lecture 23: Cytoskeleton, Cytokinesis, Myosin

• School: University of Guelph
• Department: Biology
• Course: BIOL 1090
• Professor: Andrew Bendall

Document Summary

Lecture 23 the cytoskeleton & motor proteins: 3 major elements: Made from polymers of tubulin (alpha, beta, (gamma) tubulin monomers) A dynamic network of protein filaments that forms cellular scaffolding & transport system for organelles/vesicles. 13 protofilaments form longitudinal array --> hollow cylinder: alpha end = positive --> slow-growing, heterodimers in the same direction --> create structural polarity, structural polarity = important for growth/shrinkage & direction of movement. Constant assembly (elongation) & disassembly (shrinking) of mitrotubules. Central site of microtubule assembly: ex: centrosome = major mtoc in animals. Makes mitotic spindle fibres, organizes/orients them in the right way! Formation of mts are regulated/controlled by microtubule-associated proteins (maps)! 2 main types of microtubule associated maps, can power intracellular transport: kinesin, dynesin. One mt can have both maps move along it at the same time! (each type on one side, moving opposite directions) If tau proteins are defective --> neurofibrillary tangles!!! Lamins in nucleus of all cells (makes lamina!)