MOLBIOL 3B03 Lecture Notes - Lecture 2: Microtubule Nucleation, Amyloid Precursor Protein, Neurofibrillary Tangle
5 Jan 2017
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Document Summary
Cycles work at the same time in order to trigger polymerization at one end and disassembly at the other so monomers are available in the cell. Actin polymers are formed in the three steps: nucleation monomers come tighter to form oligomers which form nuclei, slowest process, elongation oligomers are polymerized, fastest step, steady state. Nucleation step can be skipped if monomers are added to previously formed nuclei. Filament branching is the result of arp 2/3 complex bound to af. This contains a protein from the wasp family that facilitates arp2/3 branching. Vca is necessary and sufficient for efficient arp 2/3 activation. Creates a gap between themselves to allow a single actin monomer to bind to the sequence. Conformation change occurs between the addition of each monomer to the filament. Forms many oligomers which can attach at a greater rate to form filaments rather than the addition of single monomers. Spire is also used in af nucleation and branching.
