By Sulekha Rani.R,PGT Chemistry,KV NTPC kayamkulam
The Nobel Prize in Chemistry 2012 was awarded jointly to Robert J. Lefkowitz and Brian K. Kobilka "for studies of G-protein-coupled receptors"
Robert J. Lefkowitz and Brian K. Kobilka
The Nobel Prize in Chemistry 2012 was awarded jointly to Robert J. Lefkowitz and Brian K. Kobilka "for studies of G-protein-coupled receptors"
Smart
receptors on cell surfaces
Your
body is a fine-tuned system of interactions between billions of cells. Each
cell has tiny receptors that enable it to sense its environment, so it can
adapt to new situtations. Robert Lefkowitz and Brian
Kobilka are
awarded the 2012 Nobel Prize in Chemistry for groundbreaking discoveries that
reveal the inner workings of an important family of such receptors:
G-protein–coupled receptors.
For a long time, it remained a mystery how cells could sense their
environment. Scientists knew that hormones such as adrenalin had powerful
effects: increasing blood pressure and making the heart beat faster. They
suspected that cell surfaces contained some kind of recipient for hormones. But
what these receptors actually consisted of and how they worked remained obscured
for most of the 20th Century.
Lefkowitz started to use radioactivity in 1968 in order to trace
cells' receptors. He attached an iodine isotope to various hormones, and thanks
to the radiation, he managed to unveil several receptors, among those a receptor
for adrenalin: β-adrenergic receptor. His team of researchers extracted the
receptor from its hiding place in the cell wall and gained an initial
understanding of how it works.
The team achieved its next big step during the 1980s. The newly
recruited Kobilka accepted the challenge to isolate the gene that codes for the
β-adrenergic receptor from the gigantic human genome. His creative approach
allowed him to attain his goal. When the researchers analyzed the gene, they
discovered that the receptor was similar to one in the eye that captures light.
They realized that there is a whole family of receptors that look alike and
function in the same manner.
Today this family is referred to as G-protein–coupled receptors.
About a thousand genes code for such receptors, for example, for light,
flavour, odour, adrenalin, histamine, dopamine and serotonin. About half of all
medications achieve their effect through G-protein–coupled receptors.
The studies by Lefkowitz and Kobilka are crucial for understanding
how G-protein–coupled receptors function. Furthermore, in 2011, Kobilka
achieved another break-through; he and his research team captured an image of
the β-adrenergic receptor at the exact moment that it is activated by a hormone
and sends a signal into the cell. This image is a molecular masterpiece – the
result of decades of research.
