Ad
related to: polymerization of actin filaments
Search results
Results from the WOW.Com Content Network
Cell surface (cortical) actin remodeling is a cyclic (9-step) process where each step is directly responsive to a cell signaling mechanism. Over the course of the cycle, actin begins as a monomer, elongates into a polymer with the help of attached actin-binding-proteins, and disassembles back into a monomer so the remodeling cycle may commence again.
This autocatalyzed event reduces the binding strength between neighboring subunits, and thus generally destabilizes the filament. In vivo actin polymerization is catalyzed by a class of filament end-tracking molecular motors known as actoclampins. Recent evidence suggests that the rate of ATP hydrolysis and the rate of monomer incorporation are ...
A meshwork of actin filaments marks the forward edge of a moving cell, and the polymerization of new actin filaments pushes the cell membrane forward in protrusions called lamellipodia. [ 60 ] [ 61 ] [ 62 ] These membrane protrusions then attach to the substrate, forming structures known as focal adhesions that connect to the actin network. [ 62 ]
Many actin-related molecules create a free barbed end for polymerization by uncapping or severing pre-existing filaments and using these as actin nucleation cores. However, the Arp2/3 complex stimulates actin polymerization by creating a new nucleation core. Actin nucleation is an initial step in the formation of an actin filament.
Jasplakinolide binds to and stabilizes actin dimers by enhancing nucleation [2] (one of the first phases of G-actin polymerization, [4]) and thus lowering the critical concentration, or the minimum concentration needed to form filaments. [5] Phalloidin prevents filaments from polymerizing by binding between subunits in F-actin and locking them ...
The balance of F and G-actin is in a constant state of flux, which can be attributed to actin treadmilling. Actin treadmilling is the process of turnover of actin filaments where F-actin is rapidly assembled and disassembled. G-actin subunits preferentially add to the barbed end of the F-actin polymer and older units are removed from the ...
Older" ADP/ADP-Pi actin filaments free of tropomyosin and proper pH are required for cofilin to function effectively. In the presence of readily available ATP-G-actin cofilin speeds up actin polymerization via its actin-severing activity (providing free barbed ends for further polymerization and nucleation by the Arp2/3 complex). [13]
Consequently, actin polymerization only starts in this region on the surface of the bacterium. [7] Expression of ActA is induced only after entering a mammalian host cell. [8] Actin filament assembly generates the force that pushes the bacterium in the mammalian host cytoplasm forward.
Ad
related to: polymerization of actin filaments