Actin filaments, microtubules, and intermediate filaments
Variety of functions, shape and structure, cell movement, cell division, intracellular
transport, muscle contraction, axon extension, etc.
Cytoskeleton rearrangement can occur rapidly
Example of a neutrophil in pursuit of bacteria
They advance by extending protrusions at the leading edge filled with actin filaments
The cytoskeleton can form stable structures
Polarized epithelial cells: actin bundles stabilize the microvilli that increases cell surface
Each type of cytoskeletal filament is constructed from smaller protein subunits
Small subunits can diffuse rapidly within the cytoplasm whereas assembled filaments
Filaments can be rapidly disassembled at one site and reassembled in another site far
Filaments formed by multiple protofilaments have advantages
Protofilaments typically twist around each other forming lateral interactions.
Provides resistance to breakage, while the ends are dynamic.
Nucleation is the rate-limiting step in p