Department of Radiation Oncology, Baylor College of Medicine, Houston, Texas 77030, USA.
Cold Spring Harb Perspect Biol. 2011 Aug 1;3(8):a005850. doi: 10.1101/cshperspect.a005850.
Stable intercellular bridges are a conserved feature of gametogenesis in multicellular animals observed more than 100 years ago, but their function was unknown. Many of the components necessary for this structure have been identified through the study of cytokinesis in Drosophila; however, mammalian intercellular bridges have distinct properties from those of insects. Mammalian germ cell intercellular bridges are composed of general cytokinesis components with additional germ cell-specific factors including TEX14. TEX14 is an inactive kinase essential for the maintenance of stable intercellular bridges in gametes of both sexes but whose loss specifically impairs male meiosis. TEX14 acts to impede the terminal steps of abscission by competing for essential component CEP55, blocking its interaction in nongerm cells with ALIX and TSG101. Additionally, TEX14-interacting protein RBM44, whose localization in stabile intercellular bridges is limited to pachytene and secondary spermatocytes, may participate in processes such as RNA transport but is nonessential to the maintenance of intercellular bridge stability.
稳定的细胞间桥是多细胞动物配子发生中保守的特征，这一现象早在 100 多年前就被观察到了，但它们的功能尚不清楚。通过对果蝇胞质分裂的研究，已经鉴定出了许多形成这种结构所必需的成分；然而，哺乳动物细胞间桥的性质与昆虫的不同。哺乳动物生殖细胞细胞间桥由一般的胞质分裂成分组成，此外还有生殖细胞特异性因子，包括 TEX14。TEX14 是一种无活性的激酶，对于维持两性配子中稳定的细胞间桥是必需的，但它的缺失特异性地损害了雄性减数分裂。TEX14 通过与必不可少的成分 CEP55 竞争，阻止其在非生殖细胞中与 ALIX 和 TSG101 相互作用，从而阻碍了胞质分离的最后步骤。此外，TEX14 相互作用蛋白 RBM44 的定位仅限于粗线期和次级精母细胞的稳定细胞间桥中，它可能参与 RNA 运输等过程，但对于维持细胞间桥的稳定性并非必不可少。
