Tudor-related proteins TDRD1/MTR-1, TDRD6 and TDRD7/TRAP: Domain composition, intracellular localization, and function in male germ cells in mice
- 作者：Mihoko Hosokawa ; Masanobu Shoji ; Kouichi Kitamura ; Takashi Tanaka ; Toshiaki Noce ; Shinichiro Chuma ; Norio Nakatsuji
- 关键词：Germ cell ; Spermatogenesis ; Tdrd ; Tudor ; Mvh ; Vasa ; Intermitochondrial cement ; Chromatoid body ; Nuage ; Electroporation
- 刊名：Developmental Biology
- 出版年：2007
- 期刊代码：167_00121606
- 类别：bio
- 出版时间：1 January 2007
- 卷：301
- 期：1
- 页码：38-52
- 文件大小：3328 K
摘要
The germ-line cells of many animals possess a characteristic cytoplasmic structure termed nuage or germinal granules. In mice, nuage that is prominent in postnatal male germ cells is also called intermitochondrial cement or chromatoid bodies. TDRD1/MTR-1, which contains Tudor domain repeats, is a specific component of the mouse nuage, analogously to Drosophila Tudor, a constituent of polar granules/nuage in oocytes and embryos. We show that TDRD6 and TDRD7/TRAP, which also contain multiple Tudor domains, specifically localize to nuage and form a ribonucleoprotein complex together with TDRD1/MTR-1. The characteristic co-localization of TDRD1, 6 and 7 was disrupted in a mutant of mouse vasa homologue/DEAD box polypeptide 4 (Mvh/Ddx4), which encodes another evolutionarily conserved component of nuage. In vivo over-expression experiments of the TDRD proteins and truncated forms during male germ cell differentiation showed that a single Tudor domain is a structural unit that localizes or accumulates to nuage, but the expression of the truncated, putative dominant negative forms is detrimental to meiotic spermatocytes. These results indicate that the Tudor-related proteins, which contain multiple repeats of the Tudor domain, constitute an evolutionarily conserved class of nuage components in the germ-line, and their localization or accumulation to nuage is likely conferred by a Tudor domain structure and downstream of Mvh, while the characteristic repeated architecture of the domain is functionally essential for the differentiation of germ cells.