A brief review of noncoding RNA

Abstract

The genetic code for every organism is stored in biomolecules the deoxyribonucleic acid (DNA) and the ribonucleic acid (RNA). In higher organisms, DNA is found inside the nucleus while RNA is found outside the nucleus. While gene, which is directly responsible for the coding of proteins which are needed by the organism, constitutes only around one per cent of DNA, the remaining 99 per cent is noncoding. Coding RNA generally refers to mRNA that encodes protein, noncoding RNAs  act as cellular regulators without encoding proteins. Although two-thirds of the human genome get transcribed, only 2% of the transcribed genome encodes proteins. It has been found that the remaining gets converted into long ncRNA and other ncRNAs. Noncoding RNA molecules known right from the early days of molecular biology are molecules like tRNA and rRNA. Long ncRNAs (lncRNA) were thought of as transcriptional noise even in the genomic era, but it has been found that they act as regulators at different levels of gene expression including chromatin organisation, transcriptional regulation and post-transcriptional control. This means that long ncRNAs control all stages of cell biogenesis and have critical roles in cell development and diseases. As much as they are vital to the development, evidence from research proves that mutations and dysregulations of these long ncRNA molecules are linked to diverse human diseases ranging from neuro-degeneration to cancers. The noncoding gene which was largely ignored in the initial days of molecular biology has come to the centre space after the prime role it occupies in the various stages of biogenesis of organisms has come to light. The study of such molecules is vital and central in molecular biology today and they are immensely researched in drug discovery too.