Elliott D J, Oghene K, Makarov G, Makarova O, Hargreave T B, Chandley A C, Eperon I C, Cooke H J
Medical Research Council Genetics Unit, Western General Hospital, Edinburgh, Scotland.
J Cell Sci. 1998 May;111 ( Pt 9):1255-65. doi: 10.1242/jcs.111.9.1255.
RBM is a germ-cell-specific RNA-binding protein encoded by the Y chromosome in all mammals, implying an important and evolutionarily conserved (but as yet unidentified) function during male germ cell development. In order to address this function, we have developed new antibody reagents to immunolocalise RBM in the different cell types in the human testis. We find that RBM has a different expression profile from its closest homologue hnRNPG. Despite its ubiquitous expression in all transcriptionally active germ cell types, RBM has a complex and dynamic cell biology in human germ cells. The ratio of RBM distributed between punctate nuclear structures and the remainder of the nucleoplasm is dynamically modulated over the course of germ cell development. Moreover, pre-mRNA splicing components are targeted to the same punctate nuclear regions as RBM during the early stages of germ cell development but late in meiosis this spatial association breaks down. After meiosis, pre-mRNA splicing components are differentially targeted to a specific region of the nucleus. While pre-mRNA splicing components undergo profound spatial reorganisations during spermatogenesis, neither heterogeneous ribonucleoproteins nor the transcription factor Sp1 show either developmental spatial reorganisations or any specific co-localisation with RBM. These results suggest dynamic and possibly multiple functions for RBM in germ cell development.
RBM是一种在所有哺乳动物中由Y染色体编码的生殖细胞特异性RNA结合蛋白，这意味着它在雄性生殖细胞发育过程中具有重要且在进化上保守（但尚未明确）的功能。为了探究该功能，我们开发了新的抗体试剂，用于在人类睾丸的不同细胞类型中对RBM进行免疫定位。我们发现RBM与其最接近的同源物hnRNPG具有不同的表达谱。尽管RBM在所有转录活跃的生殖细胞类型中普遍表达，但它在人类生殖细胞中具有复杂且动态的细胞生物学特性。在生殖细胞发育过程中，分布在点状核结构和核质其余部分之间的RBM比例会动态调节。此外，在生殖细胞发育早期，前体mRNA剪接成分与RBM靶向相同的点状核区域，但在减数分裂后期这种空间关联会瓦解。减数分裂后，前体mRNA剪接成分被差异靶向到细胞核的特定区域。虽然前体mRNA剪接成分在精子发生过程中经历了深刻的空间重组，但异质性核糖核蛋白和转录因子Sp1既没有显示出发育性空间重组，也没有与RBM有任何特异性共定位。这些结果表明RBM在生殖细胞发育中具有动态且可能多种功能。
