Discovery of microRNAs

Introduction

Recently, Victor Ambros and Gary Ruvkun were awarded nobel prize in physiology for the discovery of microRNA and its role in post-transcriptional gene regulation.

Gene regulation

Gene regulation is how a cell controls which genes, out of many genes in its genome, are expressed, allowing for production of a specific protein. Genetic information flows from DNA to messenger RNA (mRNA), via a process called transcription, and then on to the cellular machinery for protein production. Human organs and tissues consist of different cell types, all with identical genetic information stored in their DNA. However, due to gene regulation, these different cells (like muscle cells, nerve cells etc.) express unique sets of proteins, enabling them to perform their specialized functions.

microRNA

• microRNAs are small non-coding RNA (single-stranded molecules playing key role in turning DNA instructions into proteins) that helps cells regulate gene expression. microRNA controls gene expression by binding with mRNA and preventing them from being translated into proteins or by degrading mRNA altogether. There are more than a thousand genes for different microRNAs in humans, and gene regulation by microRNA is universal among multicellular organisms.
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• Ribonucleic Acid

  • RNA is a polymer of ribonucleotides and an important biological macromolecule that is present in all biological cells. It is principally involved in the synthesis of proteins, carrying the messenger instructions from Deoxyribonucleic acid (DNA), which itself contains the genetic instructions required for the development and maintenance of life.
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  • RNA differs from DNA in three basic respects:

    • 1. RNA employs uracil as a nitrogenous base, in place of the thymine used in DNA.
      
    • 2. RNA nucleotides possess a hydroxyl group at the 2^nd position, while DNA is deoxygenated at that position to a proton.
    • 3. RNA is more often found single-stranded than DNA, which is typically completely base-paired into a double helix.
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