Actin Actin filaments are thin polarized polymers and are shorter and more

Actin actin filaments are thin polarized polymers and

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Assembly of Actin Monomers Actin filaments are composed of globular G-actin monomers that assemble in the presence of K+ and Mg2+ into a double-stranded helix of filamentous F-actin Filamentous actin (F-actin) is a linear structure consisting of two protofilaments that twist along their length The control and regulation of the polymerization process depends on the local concentration of G-actin and the interaction of actin-binding proteins (ABPs) , which can prevent or enhance polymerization. 22
23 Cytoskeletal filaments are dynamic: Constantly undergoing assembly and disassembly TREADMILLIN G DYNAMIC INSTABILITY Predominant with F-actin Predominant with Microtubules Both are associated with nucleoside triphosphate hydrolysis.
24 Dynamic Instability of Microtubules is a Flip-flop Between GTP-cap and No GTP-cap Also see Panel 16-2
Motor Proteins Motor proteins called kinesins and dyneins transport cargo along microtubules Motor proteins are powered by ATP hydrolysis. Intermediate filaments are not used as tracks by motor proteins. 25
Myosin Family of Mechanochemical Proteins Myosins have the ability to convert the energy released by ATP hydrolysis into mechanical work.
Sliding of Myosin Along Actin Filaments Causes Muscles to Contract
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