Alternative exon-encoding regions of Locusta migratoria muscle myosin modulate the pH dependence of ATPase activity.
Alternative exon-encoding regions of Locusta migratoria muscle myosin modulate the pH dependence of ATPase activity.
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飞蝗肌肉肌球蛋白的替代外显子编码区域调节 ATP 酶活性的 pH 依赖性。
DOI：
10.1111/imb.12254
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Li X-D
中科院分区：
文献类型：
--
作者：
Li J;Lu Z;He J;Chen Q;Wang X;Kang L;Li X-D
虽然脊椎动物肌肉肌球蛋白重链(MHC)是由一组Mhc基因编码的，但到目前为止所研究的大多数昆虫都含有单一的Mhc基因，并通过选择性RNA剪接产生所有不同的MHC亚型。在这里，我们发现蝗虫有一个Mhc基因，它包含41个外显子，包括5个可选的排他性外显子和一个不同的包括倒数第二个外显子，可能编码360个MHC亚型。来自成年人的。我们鉴定了14种MHC亚型(包括两种相同的亚型)：4种来自飞行肌肉(胸背侧纵肌)，3种来自跳跃肌肉(后腿胫伸肌群)，7种来自腹部节间肌肉。我们从飞行肌肉和跳跃肌肉中提纯了肌球蛋白，并对其运动活性进行了表征。在中性pH条件下，飞行肌球蛋白和跳跃肌肉的肌球蛋白具有相似的体外肌动蛋白滑动活性，而前者的肌动蛋白激活的ATPase活性略高于后者。有趣的是，这两种肌球蛋白对肌动蛋白激活的ATPase活性的pH依赖性是不同的。由于这两个肌肉中的主要MHC异构体除了两个可供选择的外显子编码区外是相同的，我们认为这两个可供选择的区域调节L的pH依赖性。移行肌肌球蛋白。
Whereas the vertebrate muscle myosin heavy chains (MHCs) are encoded by a family ofMhcgenes, most insects examined to date contain a singleMhcgene and produce all of the different MHC isoforms by alternative RNA splicing. Here, we found that the migratory locust,Locusta migratoria, has oneMhcgene, which contains 41 exons, including five alternative exclusive exons and one differently included penultimate exon, and potentially encodes 360 MHC isoforms. From the adultL. migratoria, we identified 14 MHC isoforms (including two identical isoforms): four from flight muscle (the thorax dorsal longitudinal muscle), three from jump muscle (the hind leg extensor tibiae muscle) and seven from the abdominal intersegmental muscle. We purified myosins from flight muscle and jump muscle and characterized their motor activities. At neutral pH, the flight and the jump muscle myosins displayed similar levels ofin vitroactin‐gliding activity, whereas the former had a slightly higher actin‐activated ATPase activity than the latter. Interestingly, the pH dependences of the actin‐activated ATPase activity of these two myosins are different. Because the dominant MHC isoforms in these two muscles are identical except for the two alternative exon‐encoding regions, we propose that these two alternative regions modulate the pH dependence ofL. migratoriamuscle myosin.