BIOB10H3 Lecture Notes - Lecture 9: Monomer, Treadmilling, Mitosis
25 Sep 2013
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They aren"t: targeting sequence = no targeting sequence. Proteins translated in cytosol and stay there by default : some examples: Clathrin and cop proteins : proteins outside of the vesicles. Made on free ribosomes in the cytoplasm, no targeting sequence: three main components, microtubules, actin, intermediate filaments. Cytoskeleton -functions: scaffold structural support and cell shape, internal framework organize organelles within a cell, movement directs cellular locomotion and movement of materials within the cell, machinery for cell division, structure and support, intracellular transport, contractility and motility, spatial organization. Structure: hollow, cylindrical, set of globular proteins arranged in rows : profilaments, contain 13 proto filaments. A- and b- tubulin subunits: subunits polymerize to make microtubules, b- tubulin binds gtp to allow polymerization, polymerize into proto filament. 13 proto filaments arrange around a hollow core and forms the microtubule = entire rod like structure. Protofilament = strings of those alpha beta alpha beta.
