Kinkema M, Wang H, Schiefelbein J
Department of Biology, University of Michigan, Ann Arbor 48109.
Plant Mol Biol. 1994 Nov;26(4):1139-53. doi: 10.1007/BF00040695.
Myosin is believed to act as the molecular motor for many actin-based motility processes in eukaryotes. It is becoming apparent that a single species may possess multiple myosin isoforms, and at least seven distinct classes of myosin have been identified from studies of animals, fungi, and protozoans. The complexity of the myosin heavy-chain gene family in higher plants was investigated by isolating and characterizing myosin genomic and cDNA clones from Arabidopsis thaliana. Six myosin-like genes were identified from three polymerase chain reaction (PCR) products (PCR1, PCR11, PCR43) and three cDNA clones (ATM2, MYA2, MYA3). Sequence comparisons of the deduced head domains suggest that these myosins are members of two major classes. Analysis of the overall structure of the ATM2 and MYA2 myosins shows that they are similar to the previously-identified ATM1 and MYA1 myosins, respectively. The MYA3 appears to possess a novel tail domain, with five IQ repeats, a six-member imperfect repeat, and a segment of unique sequence. Northern blot analyses indicate that some of the Arabidopsis myosin genes are preferentially expressed in different plant organs. Combined with previous studies, these results show that the Arabidopsis genome contains at least eight myosin-like genes representing two distinct classes.
肌球蛋白被认为是真核生物中许多基于肌动蛋白的运动过程的分子马达。越来越明显的是，单一物种可能拥有多种肌球蛋白异构体，并且从对动物、真菌和原生动物的研究中已鉴定出至少七种不同类别的肌球蛋白。通过从拟南芥中分离和鉴定肌球蛋白基因组和cDNA克隆，研究了高等植物中肌球蛋白重链基因家族的复杂性。从三个聚合酶链反应（PCR）产物（PCR1、PCR11、PCR43）和三个cDNA克隆（ATM2、MYA2、MYA3）中鉴定出六个类肌球蛋白基因。推导的头部结构域的序列比较表明，这些肌球蛋白是两个主要类别的成员。对ATM2和MYA2肌球蛋白整体结构的分析表明，它们分别与先前鉴定的ATM1和MYA1肌球蛋白相似。MYA3似乎具有一个新的尾部结构域，带有五个IQ重复序列、一个六成员不完全重复序列和一段独特序列。Northern印迹分析表明，一些拟南芥肌球蛋白基因在不同的植物器官中优先表达。结合先前的研究，这些结果表明拟南芥基因组包含至少八个代表两个不同类别的类肌球蛋白基因。
