Tektin5, a new Tektin5 family member, is a component of the middle piece of flagella in rat spermatozoa
Tektin5, a new Tektin5 family member, is a component of the middle piece of flagella in rat spermatozoa
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DOI：
10.1002/mrd.20804
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发表时间：
2008-04-01
影响因子：
2.5
通讯作者：
Iida, Hiroshi
中科院分区：
文献类型：
--
作者：
Murayama, Emi;Yamamoto, Etsuko;Iida, Hiroshi
tektin是由一个位于纤毛和鞭毛上的纤维形成蛋白家族组成的。据报道，哺乳动物中有四种tektin，其中至少有两种Tektin2和Tektin4被证实存在于精子鞭毛中。通过PCR技术获得了TEKTIN基因家族的新成员，命名为大鼠Tektin5。大鼠Tektin5 cDNA全长1674 bp，编码62.8 kDa的558个氨基酸蛋白。Tektin5蛋白含有一个Tektin结构域以及一个非肽特征序列，这是Tektin蛋白的一个突出特征。RT-PCR分析表明，Tektin5主要在睾丸中表达，且在睾丸发育过程中表达上调。免疫印迹分析显示，Tektin5存在于大鼠精子鞭毛中，而不存在于大鼠精子头部，并且在6 M尿素处理下，Tektin5完全从大鼠精子中释放出来，但在1% Triton X-100和0.6 M硫氰酸钾处理下，Tektin5不能被提取出来。共聚焦激光扫描显微镜显示，Tektin5位于大鼠精子鞭毛的中间段，头部和主段无免疫标记。采用预包埋法的免疫金电镜发现Tektin5主要与线粒体鞘内侧相关。Tektin5可能是鞭毛稳定性和精子活力所必需的中间组分。
Tektins are composed of a family of filament-forming proteins localized in cilia and flagella. Four types of mammalian Tektins have been reported, and at least two types of Tektins, Tektin2 and Tektin4, have been verified to be present in sperm flagella. A new member of the TEKTIN gene family, which was designated as rat Tektin5, was obtained by PCR technique. Rat Tektin5 cDNA consists of 1,674 bp encoding a 62.8 kDa protein of 558 amino acids. Tektin5 protein contains a Tektin domain as well as a nonapeptide signature sequence that is a prominent feature of Tektin proteins. RT-PCR analysis indicated that Tektin5 was predominantly expressed in testis and that its expression was up-regulated during testis development. Immunoblot analyses revealed that Tektin5 is present in sperm flagella but not in heads and that it is completely released from rat spermatozoa by 6 M urea treatment, but not extracted by 1% Triton X-100 and 0.6 M potassium thiocyanate. Confocal laser scanning microscopy revealed that Tektin5 was located in the middle piece of flagella in rat spermatozoa with no immunolabeling in the heads and the principal piece. Immunogold electron microscopy adopting pre-embedding method discovered that Tektin5 is predominantly associated with the inner side of the mitochondrial sheath. Tektin5 might work as a middle piece component requisite for flagellar stability and sperm motility.