A Brief Overview of RNA
This write up is focused on the breakthroughs in RNA Biology, most of which eventually bagged Nobel Prizes for the scientists working on them. RNA (Ribonucleic acid) and all the knowledge pertaining to it today allows us to understand some very fundamental concepts, particularly regarding gene expression. This is a very brief write up, tailored to give the reader an overview, driven by the writer’s own passion.
Very first Discovery:To identify RNA in a cell, it is essential to trace down how it is being made. Severo Ochoa put forth a postulate that it was being synthesized by an enzyme- a phosphorylase. This even won him a Nobel Prize, but his work was invalidated when it was discovered that phosphorylase actually degrades RNA. Regardless, it is still considered a breakthrough as it contests the fact that there is such a thing as RNA.
The structure of RNA: Robert W. Holley, Har Gobind Khorana and Marshall Nirenberg shared a Nobel Prize in Medicine in 1968 for discovering the structure of alanine transfer RNA, one of the many types of RNAs that we know exist today.
Discovering its Potency: The dreaded HIV virus, a lentivirus, uses its RNA along with a reverse transcriptase (and other protein assembly) to incorporate itself in the human cell- basically to infect human cells. The scientists to whom the credit of discovering HIV reverse transcriptase goes are David Baltimore, Renato Dulbecco, and Howard Temin. They were awarded the Nobel in Medicine in 1975. The discovery of HIV as it is known today was an important hallmark in the history of mankind and medicine; not only was it a huge contribution to the field of Virology, but it paved a new way for how a disease and the diseased are treated- medically and socially.
RNA Regulations: DNA is the flagbearer of genetics and heredity. But discovering the role of RNA in protein formation could very well be termed as one of the most significant breakthroughs in biology. Later studies in RNA interference can also be regarded as significant breakthroughs.
Significance in CAS9 studies: ‘CRISPR’ (Clustered Regularly Interspaced Short Palindromic Repeats) refers to sequences of DNA found in the bacterial genome that contain fragments of viral DNA, retained from viral attacks to the bacterium. The system basically relies on the genetic machinery of bacteria- prokaryotic organisms with a very low ‘generation time’ (the time taken to give rise to a new generation)
When researchers were studying simpler CRISPR systems, they discovered that it relies on Cas9, a protein. The Cas9 endonuclease is a four-component system that includes two small RNA molecules named CRISPR RNA (crRNA) and trans-activating CRISPR RNA (tracrRNA).
High throughput RNA sequencing studies today are the stronghold of experimentation in biology. They involve using next generation technology to analyze and sequence the transcriptome- that is, the sum total of all the messenger RNA molecules of an organism.