School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
RNA. 2011 Sep;17(9):1713-26. doi: 10.1261/rna.2808411. Epub 2011 Jul 14.
Ribosomal proteins (RPs) are essential components of ribosomes, but several RPs are also present at transcription sites of eukaryotic chromosomes. Here, we report a genome-wide ChIP-on-chip analysis of the association of three representative 60S RPs with sites in the Schizosaccharomyces pombe chromosomes. All three proteins tend to bind at the same subset of coding and noncoding loci. The data demonstrate selective RNA-dependent interactions between RPs and many transcription sites and suggest that the RPs bind as components of a preassembled multiprotein complex, perhaps 60S or pre-60S subunits. These findings further indicate that the presence of RPs complexes at transcription sites might be a general feature of eukaryotic cells and functionally important. Unexpectedly, the RPs' chromosomal association is highest at centromeres and tRNA genes-the RPs were found at 167 of the 171 tRNA genes assayed. These findings raise the intriguing possibility that RP complexes are involved in tRNA biogenesis and possibly centromere functions.
核糖体蛋白（RPs）是核糖体的重要组成部分，但几种核糖体蛋白也存在于真核染色体的转录位点。在这里，我们报告了对三种代表性 60S RPs 与裂殖酵母染色体上位点的全基因组 ChIP-on-chip 分析。这三种蛋白质都倾向于与编码和非编码基因座的相同子集结合。这些数据表明 RPs 与许多转录位点之间存在选择性的 RNA 依赖性相互作用，并表明 RPs 作为预先组装的多蛋白复合物的组成部分结合，可能是 60S 或前 60S 亚基。这些发现进一步表明，RPs 复合物在转录位点的存在可能是真核细胞的普遍特征，并且具有重要的功能。出乎意料的是，RPs 在着丝粒和 tRNA 基因处的染色体结合最高——在检测到的 171 个 tRNA 基因中，有 167 个存在 RPs。这些发现提出了一个有趣的可能性，即 RP 复合物参与 tRNA 生物发生，可能还有着丝粒功能。
