Long noncoding RNAs (long ncRNAs)

Article By:

Nagano, Takashi Laboratory of Chromatin and Gene Expression, The Babraham Institute, Cambridge, United Kingdom.

Last reviewed:2011

DOI:https://doi.org/10.1036/1097-8542.YB110075

Long noncoding RNAs (long ncRNAs), a group of ncRNAs (that is, RNAs without protein-coding potential), are emerging as important regulatory components in the cell. Many ncRNAs can be clearly classified on the basis of established features into ribosomal RNA (rRNA), transfer RNA (tRNA), small nuclear RNA (snRNA), small nucleolar RNA (snoRNA), microRNA (miRNA), and so forth. These groups have distinct features of their own, and the members of each group are thought to share similar function. However, substantial numbers of ncRNAs are unclassified in either of these two groups. The dominant ones among them are relatively long (more than 200 nucleotides up to 100,000 nucleotides or more), so they are collectively called long ncRNAs or macroRNAs. The term mRNA-like ncRNAs is also applicable to many of them, which share several features with protein-coding messenger RNA (mRNA), including posttranscriptional modifications through 5^′ capping, splicing, and polyadenylation tailing (addition of adenine nucleotides to the 3^′ end of mRNA molecules). However, unlike the other ncRNA groups, there is no common feature among the long ncRNAs that suggests their function.

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