Discovery of Telomere and Telomerase: the story leading to Nobel Prize 2009 for Elizabeth Blackburn, Carol W. Greider and Jack W. Szostak.


The connection between cellular ageing and telomere length is rooted in solid research. Telomeres become shorter every time your cell divides, and when they are lost cells can no longer reproduce. The enzyme telomerase can lengthen telomeres, possibly slowing or reversing degenerative diseases. This article tells the story of two women scientists who discovered it leading them with Jack Szistak to receive the Nobel Prize in 2009.


Picture of telomere:

telomere - ends of chromosomes

Telomerases are part of a distinct subgroup of RNA-dependent polymerases. Telomerase lengthens telomeres in DNA strands.


Carol W. Greider discovered the enzyme telomerase in 1984, when she was a graduate student of Elizabeth Blackburn at the University of California, Berkeley.


Professor Elizabeth Blackburn is an Australian born researcher at the University of California, San Francisco, who studies the telomere, a structure at the end of chromosomes that protects the chromosome.

 

Carol Greider Prof Elizabeth Blackburn Jack-szostak
L-R: Carol Greider, Elizabeth Blackburn, and Jack Szostak were awarded the 2009 Nobel Prize in Physiology or Medicine for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase

 

They co-discovered telomerase, the enzyme that replenishes the telomere. For this work, they were awarded the 2009 Nobel Prize in Physiology or Medicine, sharing it withand Jack W. Szostak.

Greider joined the laboratory of Elizabeth Blackburn in April, 1984, and took on a project Blackburn considered intimidating: finding the enzyme that was hypothesized to add extra DNA bases to the ends of chromosomes. Without the extra bases, which are added as repeats of a six base pair motif, chromosomes are shortened during DNA replication, eventually resulting in chromosome deterioration and senescence or cancer-causing chromosome fusion. Blackburn and Greider looked for the enzyme in the model organism Tetrahymena thermophila, a fresh-water protozoan with a large number of telomeres.

Blackburn reports that Greider approached the research with diligence, often working twelve-hour shifts in the lab.

On Christmas Day, 1984, Greider first obtained results indicating that she had found the responsible enzyme. An additional six months of research led Greider and Blackburn to the conclusion that they had, indeed, identified the enzyme responsible for telomere addition. They published their findings in the journal Cell in December, 1985. The enzyme, originally called "telomere terminal transferase," is now known as telomerase.

Elizabeth Blackburn also has other awards including the Medal of Honor from the American Cancer Society, Companion of the Order of Australia, and is listed on the list of TIME magazine of 100 People who shaped our world. She is also president of the American Association for Cancer Research (2010).