Sornjai Wannapa, Lithanatudom Pathrapol, Erales Jenny, Joly Philippe, Francina Alain, Hacot Sabine, Fucharoen Suthat, Svasti Saovaros, Diaz Jean Jacques, Mertani Hichem C, Smith Duncan R
Institute of Molecular Bioscience, Mahidol University, Thailand.
Institute of Molecular Bioscience, Mahidol University, Thailand; Department of Biology, Faculty of Science, Chiang Mai University, Thailand.
Int J Biol Macromol. 2017 Jan;94(Pt A):728-734. doi: 10.1016/j.ijbiomac.2016.10.039. Epub 2016 Oct 17.
Ribosome biogenesis is the process of synthesis of the cellular ribosomes which mediate protein translation. Integral with the ribosomes are four cytoplasmic ribosomal RNAs (rRNAs) which show extensive post-transcriptional modifications including 2'-O-methylation and pseudouridylation. Several hereditary hematologic diseases including Diamond-Blackfan anemia have been shown to be associated with defects in ribosome biogenesis. Thalassemia is the most important hematologic inherited genetic disease worldwide, and this study examined the post-transcriptional ribose methylation status of three specific active sites of the 28S rRNA molecule at positions 1858, 4197 and 4506 of β-thalassemia trait carriers and normal controls. Samples from whole blood and cultured erythroid cells were examined. Results showed that site 4506 was hypermethylated in β-thalassemia trait carriers in both cohorts. Expression of fibrillarin, the ribosomal RNA methyltransferase as well as snoRNAs were additionally quantified by RT-qPCR and evidence of dysregulation was seen. Hemoglobin E trait carriers also showed evidence of dysregulation. These results provide the first evidence that ribosome biogenesis is dysregulated in β-thalassemia trait carriers.
核糖体生物合成是细胞核糖体的合成过程,核糖体介导蛋白质翻译。与核糖体结合的是四种细胞质核糖体RNA(rRNA),它们显示出广泛的转录后修饰,包括2'-O-甲基化和假尿苷化。包括先天性纯红细胞再生障碍性贫血在内的几种遗传性血液疾病已被证明与核糖体生物合成缺陷有关。地中海贫血是全球最重要的血液学遗传性疾病,本研究检测了β地中海贫血特征携带者和正常对照者28S rRNA分子在1858、4197和4506位三个特定活性位点的转录后核糖甲基化状态。检测了全血和培养的红系细胞样本。结果显示,在两个队列的β地中海贫血特征携带者中,4506位点均发生了高甲基化。此外,通过RT-qPCR对核糖体RNA甲基转移酶fibrillarin以及小核仁RNA(snoRNA)的表达进行了定量,并发现了失调的证据。血红蛋白E特征携带者也显示出失调的证据。这些结果首次证明了β地中海贫血特征携带者的核糖体生物合成失调。