Mouse MAELSTROM: the link between meiotic silencing of unsynapsed chromatin and microRNA pathway?
Mouse MAELSTROM: the link between meiotic silencing of unsynapsed chromatin and microRNA pathway?
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DOI：
10.1093/hmg/ddl158
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发表时间：
2006-08-01
影响因子：
3.5
通讯作者：
Cooke, Howard J.
中科院分区：
文献类型：
--
作者：
Costa, Yael;Speed, Robert M.;Cooke, Howard J.
非突触染色质减数分裂沉默（MSUC）是精子发生的重要机制，也是研究基因沉默动力学的模型系统。在这里，我们表明，MAEL，果蝇的高迁移率族蛋白大漩涡的直系同源物，不仅与沉默的XY体，但也与非突触常染色体。MAEL的表征表明，它直接与染色质重塑SNF 5/INI 1和染色质相关蛋白SIN 3B相互作用，我们也发现其定位于XY体。这是第一次染色质重塑已被证明与整个染色体。此外，我们表明，MAEL是小鼠减数分裂nuage和它的单倍体细胞对应物，拟染色体体的组成部分。这是RNA和RNA加工酶的积累位点，包括参与microRNA（miRNA）途径的蛋白质。此外，在nuage中，MAEL存在于与生殖细胞特异性MVH、RNA解旋酶和Argonaute家族成员MILI和MIWI的复合物中。MAEL在雄性生殖细胞的这些关键区室中的存在及其相互作用提供了一个链接，表明MSUC中的miRNA途径的参与。
Meiotic silencing of unsynapsed chromatin (MSUC) is a key mechanism in spermatogenesis and a model system to study the dynamics of gene silencing. Here we show that MAEL, the ortholog of Drosophila's high mobility group box protein Maelstrom, is associated not only with the silenced XY body, but also with unsynapsed autosomes. Characterization of MAEL revealed that it interacts directly with the chromatin remodeler SNF5/INI1 and chromatin-associated protein SIN3B, which we also find localized to the XY body. This is the first time that a chromatin remodeler has been shown to associate with whole chromosomes. In addition, we show that MAEL is a component of the mouse meiotic nuage and its haploid cell counterpart, the chromatoid body. This is a site of accumulation of RNA and RNA processing enzymes, including proteins involved in the microRNA (miRNA) pathway. Furthermore, in the nuage, MAEL is present in a complex with germ cell specific MVH, an RNA helicase and Argonaute family members, MILI and MIWI. The presence of MAEL in these critical compartments of male germ cells and its interactions provide a link suggesting the involvement of the miRNA pathway in MSUC.