Uyeda T Q, Spudich J A
Department of Biochemistry, Stanford University School of Medicine, CA 94305.
Science. 1993 Dec 17;262(5141):1867-70. doi: 10.1126/science.8266074.
Myosin II, which converts the energy of adenosine triphosphate hydrolysis into the movement of actin filaments, is a hexamer of two heavy chains, two essential light chains, and two regulatory light chains (RLCs). Dictyostelium myosin II is known to be regulated in vitro by phosphorylation of the RLC. Cells in which the wild-type myosin II heavy chain was replaced with a recombinant form that lacks the binding site for RLC carried out cytokinesis and almost normal development, processes known to be dependent on functional myosin II. Characterization of the purified recombinant protein suggests that a complex of RLC and the RLC binding site of the heavy chain plays an inhibitory role for adenosine triphosphatase activity and a structural role for the movement of myosin along actin.
肌球蛋白II将三磷酸腺苷水解产生的能量转化为肌动蛋白丝的运动，它是由两条重链、两条必需轻链和两条调节轻链（RLC）组成的六聚体。已知盘基网柄菌肌球蛋白II在体外受RLC磷酸化的调节。用缺乏RLC结合位点的重组形式取代野生型肌球蛋白II重链的细胞进行了胞质分裂和几乎正常的发育，这些过程已知依赖于功能性肌球蛋白II。对纯化的重组蛋白的表征表明，RLC与重链的RLC结合位点形成的复合物对三磷酸腺苷酶活性起抑制作用，对肌球蛋白沿肌动蛋白的运动起结构作用。
