Characterization of Spetex-1, a New Component of Satellite Fibrils Associated With Outer Dense Fibers in the Middle Piece of Rodent Sperm Flagella
Characterization of Spetex-1, a New Component of Satellite Fibrils Associated With Outer Dense Fibers in the Middle Piece of Rodent Sperm Flagella
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DOI：
10.1002/mrd.21154
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发表时间：
2010-04-01
影响因子：
2.5
通讯作者：
Iida, Hiroshi
中科院分区：
文献类型：
--
作者：
Kaneko, Takane;Murayama, Emi;Iida, Hiroshi
Spetex-1是一种单倍体精子特异性基因，编码一个位于鼠类鞭毛中间的两个螺旋状基序的蛋白，鞭毛中间由轴突和轴突周围元件组成，包括外密纤维（odf）和卫星原纤维。预包埋免疫电镜清楚地显示，Spetex-1位于大鼠鞭毛中间与odf相关的卫星原纤维上。通过小岛屿发展中国家或尿素从精子中提取Spetex-1需要二硫苏糖醇，这表明含有Spetex-1的卫星原纤维的组装涉及到二硫键交联。我们在许多动物物种中发现了假定的Spetex-1同源物，在哺乳动物的Spetex-1同源物中，半胱氨酸残基和盘状线圈基元都被很好地保守了。当Spetex-1与myc标记的另一种与odf相关的丝状蛋白Tektin4共转染COS-7细胞时，这两个分子在细胞中以不同大小的聚集体共定位。这些数据表明，Spetex-1作为卫星原纤维的新成分，可能参与了精子鞭毛中间片的结构稳定性，并与Tektin4协同起作用
Spetex-1, which has been isolated by differential display as a haploid spermatid-specific gene, encodes a protein with two coiled-coil motifs located in the middle piece of flagella in rodent spermatozoa The middle piece of flagella is composed of axoneme and peri-axonemal elements including outer dense fibers (ODFs) and satellite fibrils Pre-embedding immunoelectron microscopy clearly demonstrated that Spetex-1 is located at satellite fibrils associated with ODFs in the middle piece of flagella of rat spermatozoa. Extraction of Spetex-1 from spermatozoa by SIDS or urea required dithiothreitol, suggesting crosslinking by disulfide bond is involved in the assembly of satellite fibrils containing Spetex-1 We identified putative Spetex-1 orthologs in many animal species, and both cysteine residues and coiled-coil motifs were well conserved in mammalian orthologs of Spetex-1. When Spetex-1 was co-transfected into COS-7 cells with myc-tagged Tektin4, another filamentous protein associated with ODFs, the two molecules were co-localized in various sizes of aggregates in the cells These data suggested that Spetex-1, a new component of satellite fibrils, might be involved in the structural stability of the sperm flagellar middle piece and functions in co-operation with Tektin4