EVIDENCE THAT MYOSIN DOES NOT CONTRIBUTE TO FORCE PRODUCTION IN CHROMOSOME MOVEMENT
EVIDENCE THAT MYOSIN DOES NOT CONTRIBUTE TO FORCE PRODUCTION IN CHROMOSOME MOVEMENT
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DOI：
10.1083/jcb.94.1.165
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发表时间：
1982-01-01
影响因子：
7.8
通讯作者：
INOUE, S
中科院分区：
文献类型：
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作者：
KIEHART, DP;MABUCHI, I;INOUE, S
将抗细胞质肌球蛋白的抗体显微注射到分裂活跃的细胞中，可作为肌动蛋白和肌球蛋白在染色体运动中作用的生理学试验。Mabuchi和Okuno的抗Asterias卵肌球蛋白在体外完全特异地抑制肌动蛋白激活的肌球蛋白的Mg ~（2+）-ATP酶，并且当显微注射时，抑制体内胞质分裂。显微注射抗体对后期染色体运动的速率或程度没有明显影响。无论是中央纺锤体伸长还是染色体纤维缩短都不受剂量的影响，剂量比均匀抑制所有注射细胞胞质分裂所需的剂量高8倍。这些剂量足以完全抑制这些细胞中的肌球蛋白ATP酶活性。单独用缓冲液、用肌球蛋白吸收的抗体或用非免疫γ-球蛋白，通过有丝分裂和胞质分裂正常进行。对照γ-用荧光素标记的球蛋白在2-4分钟内在整个细胞质中均匀扩散，并保持均匀分布。抗体不被排除在纺锤体区域之外。前中期染色体运动，受精，原核迁移和原核融合也不受显微注射抗肌球蛋白。抗肌球蛋白阻断肌动球蛋白的相互作用，被认为是胞质分裂中产生力的原因，但对有丝分裂或减数分裂染色体运动没有影响。肌球蛋白不参与染色体运动的力的产生。
Antibody against cytoplasmic myosin, when microinjected into actively dividing cells, provides a physiological test for the role of actin and myosin in chromosome movement. Anti-Asterias egg myosin, characterized by Mabuchi and Okuno, completely and specifically inhibits the actin activated Mg2+-ATPase of myosin in vitro and, when microinjected, inhibits cytokinesis in vivo. Microinjected antibody has no observable effect on the rate or extent of anaphase chromosome movements. Neither central spindle elongation nor chromosomal fiber shortening is affected by doses up to 8-fold higher than those required to uniformly inhibit cytokinesis in all injected cells. Such doses are sufficient to completely inhibit myosin ATPase activity in these cells. Cells injected with buffer alone, with myosin-absorbed antibody, or with nonimmune .gamma.-globulin, proceed normally through both mitosis and cytokinesis. Control .gamma.-globulin, labeled with fluorescein, diffuses to homogeneity throughout the cytoplasm in 2-4 min and remains uniformly distributed. Antibody is not excluded from the spindle region. Prometaphase chromosome movements, fertilization, pronuclear migration and pronuclear fusion are also unaffected by microinjected antimyosin. Antimyosin blocks the actomyosin interaction thought to be responsible for force production in cytokinesis but has no effect on mitotic or meiotic chromosome motion. Myosin is not involved in force production for chromosome movement.