考研资料：北京大学细胞生物学 第十章+细胞骨架(下).ppt

,,3. Function of IFs: Confer mechanical strength on tissues,Disruption of keratin networks causes blistering,Figure 10-18. The nuclear lamina. (A) Schematic drawing showing the nuclear lamina in cross-section in the region of a nuclear pore. The lamina is associated with both the chromatin and the inner nuclear membrane. (B) Electron micrograph of a portion of the nuclear lamina in a frog oocyte prepared by freeze-drying and metal shadowing. (C) Electron micrograph of metal-shadowed isolated lamin dimers (marked L). They have an overall form similar to muscle myosin (marked M), with a rodlike tail and two globular heads, but they are much smaller molecules. (B and C, courtesy of Ueli Aebi.),Summary: Cytoskeletal functions,Summary of cytoskeleton 1. Three types of cytoskeletal filaments are common to many eucaryotic cells and are fundamental to the spatial organization of these cells. The set of accessory proteins is essential for the controlled assembly of the cytoskeletal filaments(includes the motor proteins: myosins, dynein and kinesin) Cytoskeletal systems are dynamic and adaptable.Nucleation is rate-limiting step in the formation of a cytoskeletal polymer. Regulation of the dynamic behavior and assembly of the cytoskeletal filaments allows eucaryotic cells to build an enormous range of structures from the three basic filaments systems.,