McKim K S, Matheson C, Marra M A, Wakarchuk M F, Baillie D L
Department of Biological Sciences, Simon Fraser University, Burnaby, B.C. Canada.
Mol Gen Genet. 1994 Feb;242(3):346-57. doi: 10.1007/BF00280425.
Mutations in the unc-60 gene of the nematode Caenorhabditis elegans result in paralysis. The thin filaments of the muscle cells are severely disorganized and not bundled with myosin into functional contractile units. Here we report the cloning and sequence of unc-60. Two unc-60 transcripts, 1.3 and 0.7 kb in size, were detected. The transcripts share a single exon encoding only the initial methionine, yet encode proteins with homologous sequences. The predicted protein products are 165 and 152 amino acids in length and their sequences are 38% identical. Both proteins are homologous to a family of actin depolymerizing proteins identified in vertebrate, plant and protozoan systems. We propose that the unc-60 locus encodes proteins that depolymerize growing actin filaments in muscle cells, and that these proteins are required for the assembly of actin filaments into the contractile myofilament lattice of C. elegans muscle. unc-60 has an essential function in development, since one unc-60 allele, s1586, has a recessive lethal phenotype. Our characterization of s1586 has shown that it is a small deletion which disrupts both coding regions.
线虫秀丽隐杆线虫unc-60基因的突变会导致麻痹。肌肉细胞的细肌丝严重紊乱，无法与肌球蛋白聚集成功能性收缩单位。在此，我们报告unc-60的克隆及序列。检测到两种大小分别为1.3 kb和0.7 kb的unc-60转录本。这些转录本共享一个仅编码起始甲硫氨酸的单一外显子，但编码具有同源序列的蛋白质。预测的蛋白质产物长度分别为165和152个氨基酸，其序列有38%的同一性。这两种蛋白质都与在脊椎动物、植物和原生动物系统中鉴定出的肌动蛋白解聚蛋白家族同源。我们提出，unc-60基因座编码在肌肉细胞中使正在生长的肌动蛋白丝解聚的蛋白质，并且这些蛋白质是肌动蛋白丝组装成秀丽隐杆线虫肌肉收缩肌丝晶格所必需的。unc-60在发育中具有重要功能，因为一个unc-60等位基因s1586具有隐性致死表型。我们对s1586的特征分析表明，它是一个小缺失，破坏了两个编码区域。
