The Discovery of microRNAs: A Landmark in Gene Regulation and its Implications for Medicine

The Discovery of microRNAs: A Landmark in Gene Regulation and its Implications for Medicine

Sub: Sci

Sec: Biotech

Why in News

The 2024 Nobel Prize in Physiology or Medicine has been awarded to Victor Ambros and Gary Ruvkun for their groundbreaking discovery of microRNAs—small RNA molecules that play a critical role in gene regulation. This discovery has transformed our understanding of how genes are expressed in cells and opened new pathways for medical research, particularly in cancer, diabetes, and autoimmune diseases.

Revolutionizing Gene Regulation Understanding

Prior to the discovery of microRNAs, it was believed that gene regulation mainly involved transcription factors—specialized proteins that bind to DNA and determine which genes produce messenger RNA (mRNA).

Ambros and Ruvkun’s research demonstrated that gene regulation extends beyond transcription factors. MicroRNAs regulate gene expression at a later stage, post-transcription, after mRNA is produced but before proteins are synthesized.

About MicroRNAs (miRNAs):

They are small RNA molecules that regulate gene expression in eukaryotes by interfering with the translation of mRNA into proteins.

The discovery began with experiments on C. elegans, a tiny roundworm, where researchers showed that gene regulation can happen post-transcription, challenging the previous understanding that it was solely the domain of transcription factors.

By 2001, microRNAs were found to be present in invertebrates and vertebrates, and many of them were highly conserved across species, indicating that microRNA-mediated regulation is a universal mechanism.

MicroRNAs (miRNAs) are small, non-coding RNA molecules, approximately 21-24 nucleotides in length, involved in regulating gene expression.

miRNAs bind to messenger RNA (mRNA) in the cell cytoplasm to control gene expression.

They either trigger the degradation of mRNA or prevent it from being translated into proteins, thereby regulating protein production.

Underexpression of miRNA can lead to overexpression of the protein it controls, while overexpression of miRNA results in underproduction of the associated protein.

miRNAs are involved in key biological processes such as development, cell differentiation, proliferation, and apoptosis (programmed cell death).

They help maintain cellular homeostasis and respond to environmental stimuli.

Alterations in miRNA expression contribute to diseases like cancer, autoimmune disorders, and other human conditions.

Circulating miRNAs are considered potential biomarkers for diagnosis and prognosis of various diseases due to their stability in human fluids.

What is RNA?

RNA (Ribonucleic Acid) is a single-stranded molecule composed of ribose sugar, phosphate groups, and nucleotide bases (adenine, guanine, cytosine, uracil).

It plays a crucial role in various biological processes, mainly in coding, decoding, regulation, and expression of genes.

Types of RNA:

Messenger RNA (mRNA): Carries genetic information from DNA to the ribosome, where proteins are synthesized.

Transfer RNA (tRNA): Helps in translating mRNA into proteins by bringing amino acids to the ribosome during protein synthesis.

Ribosomal RNA (rRNA): A structural component of ribosomes, essential for protein synthesis.

MicroRNA (miRNA): Regulates gene expression by binding to mRNA, either degrading it or inhibiting its translation into protein.

RNA plays a central role in the process of transcription (copying genetic code from DNA to RNA) and translation (using mRNA to build proteins).

RNA is single-stranded (unlike double-stranded DNA).

RNA contains uracil instead of thymine, which is found in DNA.

RNA has a ribose sugar instead of deoxyribose found in DNA.

Gene regulation: miRNA and other small RNAs control gene expression.

Catalytic activity: Certain RNAs like ribozymes act as enzymes.

Messenger function: mRNA acts as a template for protein synthesis.

RNA-based technologies, such as mRNA vaccines, have become critical tools in developing treatments for diseases, including COVID-19.