BIOL 1090 Lecture Notes - Lecture 31: Tau Protein, Tubulin, Motor Protein

• School: University of Guelph
• Department: Biology
• Course: BIOL 1090
• Professor: Jaideep Mathur

Document Summary

Network of protein filaments that form cellular scaffolding as well as transport system for organelles and vesicles. Microtubules: hollow, unbranched tubules of tubulin out diameter 25 nm. Intermediate filaments: fibrous, various proteins diameter 10-12 nm. Microfilaments: solid, thin, branched, actin polymers diameter 8 nm. Functions of cytoskeleton: structure and support, intracellular transport, contractility and motility, spatial organization. 13 protofilaments form longitudinal array hollow cylinder. Heterodimers aligned in same direction (head to tail) structural polarity. Mts have fast-gro(cid:449)i(cid:374)g (cid:858)plus +(cid:859) e(cid:374)d a(cid:374)d slo(cid:449)-gro(cid:449)i(cid:374)g (cid:858)(cid:373)i(cid:374)us (cid:858) e(cid:374)d. Structural polarity is important for mt growth/shrinkage and direction of movement of material along mt. In vivo, leads to rapid turnover of most mts within cell (half-life is minutes) dynamic instability. Shri(cid:374)kage ca(cid:374) occur (cid:448)ery rapidly at the (cid:858)plus(cid:859) e(cid:374)d (cid:894)ter(cid:373)ed (cid:858)catastrophe(cid:859)(cid:895) Microtubule-organizing centre (mtoc) = central site of mt assembly. Formation of mts is regulated/controlled by microtubule-associated. Mediate interactions with other cellular structures (eg. vesicle/organelles) Can generate sliding force between mts: non-motor maps.