Howard Hughes Medical Institute and University of Colorado researchers have identified the protective protein "caps" that form the ends of all human chromosomes, a finding that may eventually have applications for cellular aging and human diseases.
The very end of chromosomes, known as telomeres, contain repeating chains of DNA that protect chromosomes from damage, said Peter Baumann, a Howard Hughes Medical Institute researcher working at the University of Colorado at Boulder. Portions of the telomeres are lost each time a cell divides, a process that may act as a biological clock by signaling the cell to stop dividing after a certain point.
"Scientists have long known about the DNA component of telomeres, and have described the proteins that bind close to the telomeres end," said HHMI President Thomas Cech, also a distinguished chemistry and biochemistry professor at CU-Boulder and CUs Health Sciences Center in Denver. "But a protein cap at the very end of the chromosome had been found only in certain single-cell organisms like protozoans and yeast."
A researcher in Cechs Boulder lab, Baumann spearheaded the discovery that both fission yeast and humans share the newly discovered protein, which has the attributes expected of a telomere end-binding protein. Baumann and Cech dubbed the protein "Protection of Telomeres," or POT-1.
"Part of the beauty of this surprising finding is that this POT-1 protein has been conserved through evolution from single-celled organisms to mammals," said Baumann.
A paper on the subject by Baumann and Cech appears in the May 11 issue of Science.
Cech, who shared the 1989 Nobel Prize in chemistry, became an HHMI Investigator in 1988 while a distinguished professor at CU. He remained a full-time CU faculty member until January 2000, when he became president of the Chevy Chase, Md., -based institute, the nations leading privately funded biomedical research organization and one of the worlds leading philanthropi
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Contact: Thomas Cech
cech@hhmi.org
301-215-8550
University of Colorado at Boulder
9-May-2001