Abteilung Stammzellbiologie, Forschungszentrum der Deutschen Forschungsgemeinschaft für Molekularphysiologie des Gehirns, Georg-August-Universität Göttingen, 37077 Göttingen, Germany.
J Cell Biol. 2011 Apr 4;193(1):71-80. doi: 10.1083/jcb.201009142. Epub 2011 Mar 28.
In Drosophila melanogaster oogenesis, there are 16 germline cells that form a cyst and stay connected to each other by ring canals. Ring canals allow the cytoplasmic transport of proteins, messenger ribonucleic acids, and yolk components from the nurse cells into the oocyte. In this paper, we describe the protein Rings lost (Rngo) and show that it is required for ring canal growth in germline cysts. rngo is an essential gene, and germline clones of a rngo-null allele show defects in ovary development, including mislocalization of ring canal proteins and fusion of germline cells. Rngo appears to be a ubiquitin receptor that possesses a ubiquitin-like domain, a ubiquitin-associated domain, and a retroviral-like aspartate protease (RVP) domain. Rngo binds to ubiquitin and to the 26S proteasome and colocalizes with both in germline cells, and its RVP domain is required for dimerization of Rngo and for its function in vivo. Our results thus show, for the first time, a function for a ubiquitin receptor in Drosophila development.
在黑腹果蝇的卵子发生过程中，有 16 个生殖细胞形成一个胞囊，并通过环管保持彼此连接。环管允许蛋白质、信使核糖核酸和卵黄成分从滋养细胞运送到卵母细胞。在本文中，我们描述了蛋白质 Rings lost（Rngo），并表明它是生殖细胞胞囊中环管生长所必需的。rngo 是一个必需基因，rngo 缺失等位基因的生殖细胞克隆在卵巢发育中表现出缺陷，包括环管蛋白的定位错误和生殖细胞的融合。Rngo 似乎是一种泛素受体，具有泛素样结构域、泛素相关结构域和逆转录病毒样天冬氨酸蛋白酶（RVP）结构域。Rngo 与泛素和 26S 蛋白酶体结合，并在生殖细胞中与两者共定位，其 RVP 结构域对于 Rngo 的二聚化及其在体内的功能是必需的。因此，我们的研究结果首次表明泛素受体在果蝇发育中的作用。
