A TB-RBP and Ter ATPase complex accompanies specific mRNAs from nuclei through the nuclear pores and into intercellular bridges in mouse male germ cells
A TB-RBP and Ter ATPase complex accompanies specific mRNAs from nuclei through the nuclear pores and into intercellular bridges in mouse male germ cells
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DOI：
10.1006/dbio.2002.0679
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发表时间：
2002-06-15
影响因子：
2.7
通讯作者：
Hecht, NB
中科院分区：
文献类型：
--
作者：
Morales, CR;Lefrancois, S;Hecht, NB
睾丸脑RNA结合蛋白（TB-RBP）作为脑和睾丸中的RNA结合蛋白发挥作用，与特定mRNA中存在的保守序列元件（如鱼精蛋白1和2）结合。我们在这里显示，通过RNA凝胶迁移试验，免疫沉淀，并通过一种新的原位杂交免疫组织化学技术，TB-RBP结合AKAP 4 mRNA在雄性小鼠生殖细胞。AKAP 4是纤维鞘的组分，并在精子鞭毛中起支架蛋白的作用。AKAP 4由X连锁基因编码，仅在减数分裂后（单倍体）雄性生殖细胞中表达，并且是所有精子中的必需蛋白，需要其作为蛋白或mRNA在精子细胞之间转运。AKAP 4 mRNA与TB-RBP和细胞核中的Ter ATP酶形成复合物，并且当其离开细胞核进入细胞质以及当其通过精子细胞之间的细胞间桥时与这些蛋白质保持结合。类似的mRNA-TB-RBP-Ter ATP酶的关联见于鱼精蛋白2 mRNA，其在翻译前约7天储存在减数分裂后生殖细胞的细胞质中。与此相反，没有看到与PGK-2 mRNA，这是最初在减数分裂早期转录与减数分裂后的男性生殖细胞中的转录增加。虽然PGK-2 mRNA受翻译控制，但其mRNA中缺乏TB-RBP结合序列。AKAP 4或鱼精蛋白2 mRNA-蛋白复合物在晚期雄性生殖细胞中当mRNA被翻译时解离。我们建议，TB-RBP和Ter ATP酶是一个复杂的，伴随着特定的mRNA在单倍体小鼠雄性生殖细胞的细胞内和细胞间运动的一部分。TB-RBP结合和mRNA失活的时间关系以及随后在mRNA翻译时mRNA-蛋白质复合物的解离表明在翻译抑制和/或mRNA稳定中的作用。(C)2002 Elsevier Science（美国）。
The testis brain RNA-binding protein (TB-RBP) functions as an RNA-binding protein in brain and testis, binding to conserved sequence elements present in specific mRNAs, such as protamine 1 and 2. We show here by RNA gel shift assays, immunoprecipitation, and by a novel in situ hybridization immunohistochemical technique that TB-RBP binds to AKAP4 mRNA in male mouse germ cells. AKAP4 is a component of the fibrous sheath and functions as a scaffolding protein in the sperm flagellum. AKAP4 is encoded by an X-linked gene, is expressed solely in postmeiotic (haploid) male germ cells, and is an essential protein in all spermatozoa, requiring its transport between spermatids as a protein or mRNA. AKAP4 mRNA forms a complex with TB-RBP and the Ter ATPase in nuclei and remains associated with these proteins as it exits nuclei into the cytoplasm and as it passes through intercellular bridges between spermatids. A similar mRNA-TB-RBP-Ter ATPase association is seen for protamine 2 mRNA, which is stored in the cytoplasm of postmeiotic germ cells about 7 days before translation. In contrast, no association is seen with PGK-2 mRNA which is initially transcribed early in meiosis with increased transcription in postmeiotic male germ cells. Although PGK-2 mRNA is subject to translational control, it lacks TB-RBP-binding sequences in its mRNA. The AKAP4 or protamine 2 mRNA-protein complexes dissociate in late-stage male germ cells when the mRNAs are translated. We propose that TB-RBP and the Ter ATPase are part of a complex that accompanies specific mRNAs in haploid mouse male germ cells in intracellular and intercellular movement. The temporal relationship of TB-RBP binding and mRNA inactivation in conjunction with the subsequent dissociation of the mRNA-protein complex at the time of mRNA translation suggests a role in translational suppression and/or mRNA stabilization. (C) 2002 Elsevier Science (USA).