Characterization of myosin II regulatory light chain isoforms in HeLa cells.
Characterization of myosin II regulatory light chain isoforms in HeLa cells.
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HeLa 细胞中肌球蛋白 II 调节轻链亚型的表征。
DOI：
10.1002/cm.21268
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Kozue Hamao
中科院分区：
文献类型：
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作者：
Tomo Kondo;Morihiro Okada;Kayo Kunihiro;Masayuki Takahashi;Yoshio Yaoita;Hiroshi Hosoya;Kozue Hamao
肌球蛋白II调节轻链（MRLC）是常规肌球蛋白（肌球蛋白II）的一个亚基，调节细胞的细胞质收缩性。最近的研究还揭示了MRLC的非经典功能，例如与其他蛋白质（包括非常规肌球蛋白）的结合。人类已知有三种MRLC亚型（MRLC 1、MRLC 2和MRLC 3）。MRLC 2的特性是众所周知的，但MRLC 1和MRLC 3的特性尚不清楚;因此，研究了三种MRLC亚型的特性。MRLC均在肌球蛋白II刺激所需的Thr 18/Ser 19磷酸化。在HeLa细胞中，MRLC mRNA在整个细胞周期中以相同的水平表达。MRLC相互共定位，其周转率与肌球蛋白II重链相似。所有MRLC的耗尽扰乱细胞扩散。MRLC 2或MRLC 3的过量产生，而不是MRLC 1，可以有效地弥补这一缺陷，表明MRLC 2和MRLC 3在细胞铺展中起主导作用。最后，三维蛋白质结构的计算机模拟表明，MRLC 1的N-末端位置与MRLC 2或MRLC 3不同，这取决于其序列。因此，这些MRLC同种型具有重叠但已提出不同的功能。© 2015威利期刊公司.
Myosin II regulatory light chain (MRLC) is canonically known as a subunit of conventional myosin (myosin II), which tunes cytoplasmic contractility in cells. Recent studies have also revealed the noncanonical functions of MRLC, such as engagement with other proteins including unconventional myosins. Three MRLC isoforms (MRLC1, MRLC2, and MRLC3) are known in humans. The characteristics of MRLC2 are well known, but those of MRLC1 and MRLC3 are unclear; therefore, the properties of the three MRLC isoforms were investigated. The MRLCs were all phosphorylated at Thr18/Ser19, which is required for myosin II stimulation. MRLC mRNAs were expressed at the same level throughout the cell cycle in HeLa cells. The MRLCs colocalized with each other and their turnover rate was similar to that of myosin II heavy chain. Depletion of all the MRLCs perturbed cell spreading. The overproduction of MRLC2 or MRLC3, but not MRLC1, could effectively compensate for this defect, suggesting that MRLC2 and MRLC3 play dominant roles in cell spreading. Finally, computer simulations of the three‐dimensional protein structures indicated that the location of the N‐terminus of MRLC1 differs from that of MRLC2 or MRLC3, depending on its sequence. Thus, these MRLC isoforms have overlapping but distinct functions have been proposed. © 2015 Wiley Periodicals, Inc.