Dhanoa Jasdeep Kaur, Sethi Ram Saran, Verma Ramneek, Arora Jaspreet Singh, Mukhopadhyay Chandra Sekhar
School of Animal Biotechnology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab India.
J Anim Sci Technol. 2018 Oct 25;60:25. doi: 10.1186/s40781-018-0183-7. eCollection 2018.
The central dogma of gene expression propounds that DNA is transcribed to mRNA and finally gets translated into protein. Only 2-3% of the genomic DNA is transcribed to protein-coding mRNA. Interestingly, only a further minuscule part of genomic DNA encodes for long non-coding RNAs (lncRNAs) which are characteristically more than 200 nucleotides long and can be transcribed from both protein-coding (e.g. and ) as well as non-coding DNA by RNA polymerase II. The lncRNAs do not have open reading frames (with some exceptions), 3`-untranslated regions (3'-UTRs) and necessarily these RNAs lack any translation-termination regions, however, these can be spliced, capped and polyadenylated as mRNA molecules. The flexibility of lncRNAs confers them specific 3D-conformations that eventually enable the lncRNAs to interact with proteins, DNA or other RNA molecules via base pairing or by forming networks. The lncRNAs play a major role in gene regulation, cell differentiation, cancer cell invasion and metastasis and chromatin remodeling. Deregulation of lncRNA is also responsible for numerous diseases in mammals. Various studies have revealed their significance as biomarkers for prognosis and diagnosis of cancer. The aim of this review is to overview the salient features, evolution, biogenesis and biological importance of these molecules in the mammalian system.
基因表达的中心法则表明，DNA转录为mRNA，最终翻译为蛋白质。只有2%-3%的基因组DNA转录为蛋白质编码mRNA。有趣的是，基因组DNA中只有极小一部分编码长链非编码RNA（lncRNA），其特征是长度超过200个核苷酸，可由RNA聚合酶II从蛋白质编码DNA（如……和……）以及非编码DNA转录而来。lncRNA没有开放阅读框（某些情况除外）、3`非翻译区（3'-UTR），并且这些RNA必然缺乏任何翻译终止区，然而，它们可以像mRNA分子一样进行剪接、加帽和聚腺苷酸化。lncRNA的灵活性赋予它们特定的三维构象，最终使lncRNA能够通过碱基配对或形成网络与蛋白质、DNA或其他RNA分子相互作用。lncRNA在基因调控、细胞分化、癌细胞侵袭和转移以及染色质重塑中起主要作用。lncRNA失调也与哺乳动物的多种疾病有关。各种研究已经揭示了它们作为癌症预后和诊断生物标志物的重要性。本综述的目的是概述这些分子在哺乳动物系统中的显著特征、进化、生物发生和生物学重要性。
