medicine and physiology

if there can ever be a favorite for a nobel prize, it may have been elizabeth blackburn, carol grieder, and john szostak. the speculation was that they would win for their discoveries of telomeres and telomerase. the speculation was correct, the nobel went to blackburn et al.

telomeres are dna caps on the end of chromosomes that prevent chromosomal degradation. telomerase is the enzyme which adds the telomeric dna to the chromosomes and facilitates its maintenance.

here is an image of human chromosomes with fluorescently tagged telomeres.
interestingly, this image probably utilizes green fluorescent protein, which was the discovery for which last year's chemistry nobel prize was awarded.

telomeres are important because they provide a protective end cap for the the chromosome. while the end cap is in place, the chromosomes are protected, and able to replicate without getting all mutated and old. liz blackburn once compared telomeres to to the ends of shoelaces that keep them from unraveling. the eventual shortening of telomeres, as cells divide, is thought to be a primary cause of aging. once your telomeres get short, after years of using them, your shoelaces start to unravel.

telomerase is the enzyme responsible for building and maintaining the telomeres. it's a pretty cool enzyme because it has both a protein and an rna component. i'm a big fan of rna, so i'm always happy to see a nobel prize awarded for a discovery that's even loosely related. the protein portion of telomerase uses the rna portion of telomerase as a template for synthesizing the telomeres.

one interesting thing about telomeres and telomerase is their seemingly paradoxical implications to aging and cancer. the telomeres protect the chromosomes from damage. as cells divide over multiple generations, the telomeres eventually shrink, and the cells get old and die. it would seem that if we could come up with a way to make telomerase function better in cells, or function forever, we could better protect the chromosomes, and make cells live forever. however, instead of being the fountain of youth, cells which are immortalized through telomerase up-regulation become cancerous. it turns out that telomeres are the key to cancer cells being able to divide indefinitely. quite the paradox.


with roles in both cancer and immortality, i believe one can easily see why this discovery was worthy of a nobel prize. unless there is some grad student who isn't being properly recognized here, or some scorned co-collaborator, my guess is that this won't be a very controversial award.