Effect of Mts1 on the structure and activity of nonmuscle myosin II
Effect of Mts1 on the structure and activity of nonmuscle myosin II
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DOI：
10.1021/bi971182l
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发表时间：
1997-12-23
期刊：
影响因子：
2.9
通讯作者：
Zain, SB
中科院分区：
文献类型：
--
作者：
Ford, HL;Silver, DL;Zain, SB
mts1基因编码一个9kda的蛋白，属于Ca2+结合蛋白的S100亚家族，已知在转移中起作用。mts1在转移中的作用可能是通过细胞运动，因为转染mts1到小鼠乳腺腺癌细胞中增加了改良Boyden趋化室的细胞运动。Mts1蛋白在Ca2+存在下与非肌肉肌球蛋白II相互作用，其亲和力约为7.9 x 10(4) M-1，其化学计量量约为3mol Mts1/mol肌球蛋白重链。未发现与肌球蛋白I或肌球蛋白v的相互作用。Mts1与肌球蛋白的结合位点在棒状区域，特别是在棒状的轻肌球蛋白部分。为了了解Mts1改变细胞运动的机制，我们研究了它对肌球蛋白结构和活性的影响。共沉分析和电镜分析表明，Mts1破坏肌球蛋白丝的稳定性，在Ca2+存在下，Mts1抑制肌动蛋白激活的MgATPase活性。这些数据证明了Mts1对肌球蛋白结构和功能的影响，并提出了Mts1影响运动和转移的途径。
The mts1 gene codes for a 9 kDa protein belonging to the S100 subfamily of Ca2+-binding proteins and is known to play a role in metastasis. Its role in metastasis may be through cellular locomotion, as transfection of mts1 into mouse mammary adenocarcinoma cells increases cellular motility in modified Boyden chemotaxis chambers. The Mts1 protein interacts with nonmuscle myosin II in the presence of Ca2+ with an affinity of approximately 7.9 x 10(4) M-1 and an approximate stoichiometry of 3 mol of Mts1/mol of myosin heavy chain. No interaction was found with myosin I or myosin V. The binding site of Mts1 on myosin is in the rod region, particularly to the light meromyosin portion of the rod, To understand the mechanism by which Mts1 alters cellular motility, we examined its effect on myosin structure and activity. Cosedimentation analysis and electron microscopy suggest that Mts1 destabilizes myosin filaments, In the presence of Ca2+, Mts1 inhibits the actin-activated MgATPase activity of myosin in vitro. The data demonstrate an effect of Mts1 on both myosin structure and function, and suggest a route through which Mts1 affects motility as well as metastasis.