New face of the “RNA world”

Agata Tyczewska, Marek Figlerowicz


For a very long time, RNA was considered just the medium by which information flows from DNA into the cell. The model proposed in the 1960s assumed that proteins are the main products and regulators of the gene expression process. In this context, the results of the Human Genome Project and the discoveries of RNA interference and small regulatory RNAs (srRNAs) came as a true surprise. The first ones demonstrated that less than 5% of the human genome encodes proteins. The second showed that RNA, especially 20-30 nt-long molecules should be placed among the most important factors controlling gene expression. srRNAs are capable of affecting the release and flow of genetic information in many different ways. They can induce changes in the genome structure, inhibit transcription, mediate mRNA degradation and repress translation. Interestingly, in different organisms, different pathways are used to regulate gene expression. It has recently been estimated that, in humans, the expression of 35-40% of genes is controlled by srRNA. As a result, RNA is currently believed to be a central molecule in many biological processes.


non-coding RNA; small regulatory RNA; gene expression; RNA world

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