ATP ATP PDB 2BTE G-actin PDB 2BTF G-actin Actin monomer, depicted above in two display modes, has subdomains 1-4 ATP A simplified cartoon is at right ATP binds, along with Mg+t, within a deep cleft between subdomains 2&4 Actin monomer with bound
Actin monomer, depicted above in two display modes, has subdomains 1-4. A simplified cartoon is at right. ATP binds, along with Mg++, within a deep cleft between subdomains 2 & 4. Actin monomer with bound ATP PDB 2BTF G-actin ATP PDB 2BTF G-actin ATP 1 2 3 4
A ATP (B) G-肌动蛋白与F-肌动蛋白模式图
G-肌动蛋白与F-肌动蛋白模式图
(二)肌动蛋白纤维的装配 ◆装配过程 成核( nucleation) ●稳定状态( steady state)
(二)肌动蛋白纤维的装配 ◆装配过程 ● 成核(nucleation) ● 延伸(elongation) ● 稳定状态(steady state)
微丝的装配 Nucleus nUcleus Nucleus F-actin F-actin G-actin o(-)end (+)end O Nucleation Elongation Steady state
微丝的装配
Lamellipodia are thin but broad projections at the edge of a mobile cell Lamellipodia are dynamic structures, constantly changing shape Movie on lamellipodial action in wound closure at FishScope web site Lamellipodia contain extensively branched arrays of actin filaments, oriented with their plus(barbed) ends toward the plasma membrane Forward extension of a lamellipodium occurs b growth of actin filaments adjacent to the plasma membrane at the leading edge of a moving cell
Lamellipodia are thin but broad projections at the edge of a mobile cell. Lamellipodia are dynamic structures, constantly changing shape. Movie on lamellipodial action in wound closure at FishScope web site. Lamellipodia contain extensively branched arrays of actin filaments, oriented with their plus (barbed) ends toward the plasma membrane. Forward extension of a lamellipodium occurs by growth of actin filaments adjacent to the plasma membrane at the leading edge of a moving cell