Identification, characterization and cloning of myr 1, a mammalian myosin-I.
Identification, characterization and cloning of myr 1, a mammalian myosin-I.
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DOI：
10.1083/jcb.120.6.1393
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发表时间：
1993-03
影响因子：
7.8
通讯作者：
Bahler, M
中科院分区：
文献类型：
--
作者：
Ruppert, C;Kroschewski, R;Bahler, M
我们已经鉴定、鉴定和克隆了一种新的哺乳动物肌球蛋白-I马达分子，称为myr 1（来自大鼠的肌球蛋白-I）。MYR 1有三种剪接形式：MYR 1a、MYR 1b和MYR 1c。这些剪接形式的不同之处在于其推定的钙调蛋白/轻链结合位点的数量。Myr 1a-c被ATP选择性地释放，以核苷酸依赖的方式与F-肌动蛋白结合，并表现出肌球蛋白-I马达结构域的特征性氨基酸序列。除了马达结构域，它们还含有一个调节结构域，具有多达6个推定的钙调蛋白/轻链结合位点和一个尾结构域。尾部结构域表现出47%的氨基酸序列的刷状缘肌球蛋白-I尾部结构域的同一性，表明MYR 1是唯一的其他哺乳动物肌球蛋白-I马达分子，迄今已被表征。与在成熟肠上皮细胞中表达的刷状缘肌球蛋白-I相反，MYR 1剪接形式在所有测试组织中差异表达。因此，myr 1是第一个在新生儿和成人组织中广泛分布的哺乳动物肌球蛋白-I运动分子。myr 1a剪接形式优先在神经元组织中表达。它的表达在大鼠前脑个体发育和亚细胞分级显示富集纯化的生长锥颗粒，数据与MYR 1A在神经元发育中的作用一致。
We have identified, characterized and cloned a novel mammalian myosin-I motor-molecule, called myr 1 (myosin-I from rat). Myr 1 exists in three alternative splice forms: myr 1a, myr 1b, and myr 1c. These splice forms differ in their numbers of putative calmodulin/light chain binding sites. Myr 1a-c were selectively released by ATP, bound in a nucleotide-dependent manner to F-actin and exhibited amino acid sequences characteristic of myosin-I motor domains. In addition to the motor domain, they contained a regulatory domain with up to six putative calmodulin/light chain binding sites and a tail domain. The tail domain exhibited 47% amino acid sequence identity to the brush border myosin-I tail domain, demonstrating that myr 1 is related to the only other mammalian myosin-I motor molecule that has been characterized so far. In contrast to brush border myosin-I which is expressed in mature enterocytes, myr 1 splice forms were differentially expressed in all tested tissues. Therefore, myr 1 is the first mammalian myosin-I motor molecule with a widespread tissue distribution in neonatal and adult tissues. The myr 1a splice form was preferentially expressed in neuronal tissues. Its expression was developmentally regulated during rat forebrain ontogeny and subcellular fractionation revealed an enrichment in purified growth cone particles, data consistent with a role for myr 1a in neuronal development.