The term ribonucleic acid – RNA – conjures up images of a nucleic acid that merely serves as a mediator of information between DNA and proteins. It is seen as just a second step in the pathway to protein synthesis, and because of this dismissal of its significance, RNA research for decades was not assigned the same importance as that of DNA or proteins.
However, a few major breakthroughs led to a radical shift in the perception of RNA’s role in the body. The discovery of ribozymes by Yale professors Thomas Cech and Sidney Altman showed that RNA could catalyze reactions. This led to the proposal of the RNA world hypothesis, which claimed that RNA was the original nucleic acid because it contained catalytic properties, and that DNA eventually evolved from RNA.
“Small RNAs are just 21-28 nucleotides long, but they are responsible
for regulating the expression of particular genes.
Yin explained that the discovery of small RNAs “initiated a whole new field of non-coding
RNA studies, in that these non-coding small RNAs have important roles in controlling
gene expression and preventing host genome from foreign DNA invasion.”
AUTHOR
In the past decade, the unearthing of small RNAs led to an explosion in the fields of biomedical research and medicine, and was dubbed the “Breakthrough of the Year” byScience magazine in 2002. The existence of small RNAs revealed that RNA plays a much more active role in regulating cellular processes than once assumed.
Dr. Haifan Lin, Professor of Cell Biology and Director of the Yale Stem Cell Center, capitalized on this newfound role of RNA in the body. Together, Lin and his graduate student, Hang Yin, discovered piRNAs, a subclass of small RNAs that play an integral role in regulating gene expression.