Weigt C, Just I, Wegner A, Aktories K
Institute of Physiological Chemistry, Ruhr-University Bochum, FRG.
FEBS Lett. 1989 Mar 27;246(1-2):181-4. doi: 10.1016/0014-5793(89)80279-0.
The effect of nonmuscle actin ADP-ribosylated by botulinum C2 toxin on the polymerization of nonmuscle actin was investigated in order to clarify whether nonmuscle actin is converted into a capping protein by ADP-ribosylation. ADP-ribosylated actin was found to decrease the rate of polymerization of actin filaments which are free at both ends. ADP-ribosylated actin turned out to have no effect on the rate or extent of polymerization at the pointed ends of actin filaments the barbed ends of which were capped by gelsolin. The monomer concentration reached at the final stage of polymerization was similar to the critical concentration of the pointed ends of actin filaments. The results suggest that nonmuscle actin ADP-ribosylated by botulinum C2 toxin acts as a capping protein which binds to the barbed ends to inhibit polymerization.
为了阐明非肌肉肌动蛋白是否通过ADP-核糖基化转化为封端蛋白，研究了肉毒杆菌C2毒素ADP-核糖基化的非肌肉肌动蛋白对非肌肉肌动蛋白聚合的影响。发现ADP-核糖基化的肌动蛋白降低了两端自由的肌动蛋白丝的聚合速率。结果表明，由凝溶胶蛋白封端的肌动蛋白丝的尖端处，ADP-核糖基化的肌动蛋白对聚合速率或程度没有影响。聚合最后阶段达到的单体浓度与肌动蛋白丝尖端的临界浓度相似。这些结果表明，肉毒杆菌C2毒素ADP-核糖基化的非肌肉肌动蛋白作为一种封端蛋白，与肌动蛋白丝的尖端结合以抑制聚合。
