Fernández-Pevida Antonio, Kressler Dieter, de la Cruz Jesús
Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain; Departamento de Genética, Universidad de Sevilla, Sevilla, Spain.
Wiley Interdiscip Rev RNA. 2015 Mar-Apr;6(2):191-209. doi: 10.1002/wrna.1267. Epub 2014 Oct 18.
Most, if not all RNAs, are transcribed as precursors that require processing to gain functionality. Ribosomal RNAs (rRNA) from all organisms undergo both exo- and endonucleolytic processing. Also, in all organisms, rRNA processing occurs inside large preribosomal particles and is coupled to nucleotide modification, folding of the precursor rRNA (pre-rRNA), and assembly of the ribosomal proteins (r-proteins). In this review, we focus on the processing pathway of pre-rRNAs of cytoplasmic ribosomes in the yeast Saccharomyces cerevisiae, without doubt, the organism where this pathway is best characterized. We summarize the current understanding of the rRNA maturation process, particularly focusing on the pre-rRNA processing sites, the enzymes responsible for the cleavage or trimming reactions and the different mechanisms that monitor and regulate the pathway. Strikingly, the overall order of the various processing steps is reasonably well conserved in eukaryotes, perhaps reflecting common principles for orchestrating the concomitant events of pre-rRNA processing and ribosome assembly.
大多数（即便不是所有）RNA转录时都是以前体形式存在，需要经过加工才能获得功能。所有生物体中的核糖体RNA（rRNA）都要经历外切核酸酶和内切核酸酶加工。此外，在所有生物体中，rRNA加工都发生在大型前核糖体颗粒内部，并与核苷酸修饰、前体rRNA（pre-rRNA）折叠以及核糖体蛋白（r-蛋白）组装相偶联。在本综述中，我们聚焦于酿酒酵母细胞质核糖体pre-rRNA的加工途径，毫无疑问，在该生物体中这一途径得到了最充分的表征。我们总结了目前对rRNA成熟过程的理解，特别关注pre-rRNA加工位点、负责切割或修剪反应的酶以及监测和调节该途径的不同机制。引人注目的是，真核生物中各个加工步骤的总体顺序相当保守，这或许反映了协调pre-rRNA加工和核糖体组装相关事件的共同原则。
