Egelhoff T T, Naismith T V, Brozovich F V
Department of Physiology and Biophysics, Case Western Reserve School of Medicine, Cleveland, OH 44106-4970, USA.
J Muscle Res Cell Motil. 1996 Apr;17(2):269-74. doi: 10.1007/BF00124248.
Cortical tension in most nonmuscle cells is due largely to force production by conventional myosin (myosin II) assembled into the cytoskeleton. Cytoskeletal contraction in smooth muscle and nonmuscle cells is influenced by the degree of myosin filament assembly, and by activation of myosin motor function via regulatory light chain phosphorylation. Recombinant Dictyostelium discoideum cell lines have been generated bearing altered myosin heavy chains, resulting in either constitutive motor function or constitutive assembly into the cytoskeleton. Analysis of these cells allowed stiffening responses to agonists, measured on single cells, to be resolved into an regulatory light chain-mediated component reflecting activation of motor function, and a myosin heavy chain phosphorylation-regulated component reflecting assembly of filaments into the cytoskeleton. These two components can account for all of the cortical stiffening response seen during tested in vivo contractile events.
大多数非肌肉细胞中的皮质张力很大程度上归因于组装到细胞骨架中的传统肌球蛋白（肌球蛋白II）产生的力。平滑肌和非肌肉细胞中的细胞骨架收缩受肌球蛋白丝组装程度以及通过调节轻链磷酸化激活肌球蛋白运动功能的影响。已经产生了携带改变的肌球蛋白重链的重组盘基网柄菌细胞系，导致组成型运动功能或组成型组装到细胞骨架中。对这些细胞的分析使得在单细胞上测量的对激动剂的硬化反应能够分解为反映运动功能激活的调节轻链介导的成分，以及反映细丝组装到细胞骨架中的肌球蛋白重链磷酸化调节的成分。这两个成分可以解释在体内测试的收缩事件中观察到的所有皮质硬化反应。
