Actin and Cell Motility: Microfilaments and Assembly

They may create additional free barbed ends for growth or act as capping proteins.

They form a mesh-like network for support or parallel groupings, as seen in microvilli.

They provide anchorage for changes in membrane shape.

<p>It activates filament nucleating proteins in response to stimuli, leading to the polymerization of actin-ATP.</p> Signup and view all the answers

<p>It mediates the depolymerization of the (-) ends of capped microfilaments, releasing ADP to allow for the formation of actin-ATP.</p> Signup and view all the answers

<p>It allows for the formation of focal adhesions between the leading edge of the lamellipodium and the substratum, enabling the bulk of the cell to be moved forward by myosin and actin.</p> Signup and view all the answers

<p>The critical concentration of ATP-actin required for addition to the (+) end is lower than that for the (-) end.</p> Signup and view all the answers

<p>The Arp 2/3 complex serves as a template for the addition of actin monomers to add branches to the filament.</p> Signup and view all the answers

<p>Monomer-sequestering proteins bind to actin-ATP monomers, preventing polymerization and regulating the rate of polymerization and depolymerization.</p> Signup and view all the answers

<p>End-blocking proteins prevent the addition or loss of actin monomers at the (+) or (-) end of the filament.</p> Signup and view all the answers

<p>Depolymerizing proteins bind to the pointed end of the filament, causing depolymerization.</p> Signup and view all the answers

<p>Actin networks are typically located in the cell cortex, below the cell membrane, and are essential for cellular motility, including processes such as endocytosis, phagocytosis, and cytokinesis.</p> Signup and view all the answers