ANAT 262 Lecture Notes - Lecture 15: Intermediate Filament, Persistence Length, Dynamic Equilibrium

• School: McGill University
• Department: Anatomy & Cell Biology
• Course: ANAT 262
• Professor: John Presley

Document Summary

The cytoskeleton is an integrated network of filamentous systems that underlies both organization and dynamics of the cytoplasm. Structure and support: cell shape, tensile strength, intercellular contacts (e. g. intermediate filaments, lamin provides cellular structure support) Intracellular transport: chromosome segregation (e. g. microtubules transport to membranes) Contraction and mobility: cell division and cell movement. Two kinds of movement: (1) inherent filament dynamics (2) molecule motor-driven movement (e. g. kinesin, dyenin) Some cytoskeletal elements are more or less fixed: Microtubule-based cilia (elongated and shortened rapidly) and flagella, actin- myosin filament in muscle cells. But in general, cytoskeleton is highly dynamic, cytoskeleton is hence a misnomer (not fixed, changes under different conditions) The cytoskeleton is a group of dynamic filament systems that can undergo rapid assembly and disassembly to adapt to the needs of the cell. Dynamics are possible because filaments are made of smaller protein subunits: allow monomer to easily diffuse and reassemble into polymer, much more flexible.