THE CAENORHABDITIS-ELEGANS SPE-26 GENE IS NECESSARY TO FORM SPERMATIDS AND ENCODES A PROTEIN SIMILAR TO THE ACTIN-ASSOCIATED PROTEINS KELCH AND SCRUIN
THE CAENORHABDITIS-ELEGANS SPE-26 GENE IS NECESSARY TO FORM SPERMATIDS AND ENCODES A PROTEIN SIMILAR TO THE ACTIN-ASSOCIATED PROTEINS KELCH AND SCRUIN
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DOI：
10.1101/gad.9.9.1074
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发表时间：
1995-05-01
影响因子：
10.5
通讯作者：
WARD, S
中科院分区：
文献类型：
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作者：
VARKEY, JP;MUHLRAD, PJ;WARD, S
秀丽隐杆线虫spe-26基因的六个独立突变通过扰乱精子发生而导致雄性和两性不育。具有最严重等位基因的突变的精母细胞不能完成减数分裂，也不形成单倍体精子细胞。相反，这些精母细胞因染色体分离错误和肌动蛋白细丝、内质网和核糖体定位错误而停滞。尽管如此，一些通常将精子特定成分输送到精子细胞的细胞核和细胞器成熟，就像它们在精子细胞中一样。Spe-26基因在精原细胞和精母细胞中表达于整个睾丸。它编码一个570个氨基酸的多肽，包含5个串联重复基序，每个重复基序类似于50个氨基酸。这些重复序列类似于果蝇kelch蛋白中的重复序列，与交链肌动蛋白细丝的无脊椎动物精子蛋白scr in中的重复序列，以及小鼠和痘病毒蛋白中的重复序列。这些重复基序的功能重要性体现在以下事实中：SPE-26的五个突变位于串联重复序列中，其中最严重的突变之一是高度保守的甘氨酸的替代。这些结果表明，spe-26编码一种细胞骨架蛋白，可能是肌动蛋白结合，这是分离形成单倍体精子细胞的细胞成分所必需的。
Six independent mutations in the Caenorhabditis elegans spe-26 gene cause sterility in males and hermaphrodites by disrupting spermatogenesis. Spermatocytes in mutants with the most severe alleles fail to complete meiosis and do not form haploid spermatids. Instead, these spermatocytes arrest with missegregated chromosomes and mislocalized actin filaments, endoplasmic reticulum and ribosomes. In spite of this arrest some of the nuclei and the organelles that normally transport sperm-specific components to the spermatid mature as if they were in spermatids. The spe-26 gene is expressed throughout the testis in both spermatogonial cells and spermatocytes. It encodes a 570-amino acid polypeptide, which contains five tandem repeat motifs, each of similar to 50 amino acids. These repeats are similar in sequence to repeats in the Drosophila kelch protein, in the invertebrate sperm protein scruin that cross-links actin filaments, as well as in the mouse and pox virus proteins. The functional importance of these repeat motifs is shown by the fact that five of the spe-26 mutations are in the tandem repeats, and one of the most severe mutations is a substitution in a highly conserved glycine. These results suggest that spe-26 encodes a cytoskeletal protein, perhaps actin binding, which is necessary to segregate the cellular components that form haploid spermatids.