Stanford researchers unmask proteins in telomerase, a substance that enab...( STANFORD Calif. - One of the more in...),Health

STANFORD, Calif. - One of the more intriguing workhorses of the cell, a protein conglomerate called telomerase, has in its short history been implicated in some critical areas of medicine including cancer, aging and keeping stem cells healthy. With such a resume, telomerase has been the subject of avid interest by basic scientists and pharmaceutical companies alike, so you'd think at the very least people would know what it is.

But researchers have been frustrated in their attempts to find the proteins that make up this complex. They know that it's a behemoth of an enzyme and is made up of more than just the two components they've gotten their hands on in the past. They also know what it does: it maintains the cell's genetic material in fetal cells, normal adult stem cells and in cancer cells.

What they don't know is what other proteins make up the massive telomerase complex. Until now, that is.

Researchers at Stanford University School of Medicine have identified two new proteins that make up the telomerase complex and have a lead on several more. This is the first significant step toward understanding the makeup of telomerase since 1999. The discovery of these two proteins provides new targets for cancer treatments, the researchers said.

"It's so surprising that we are discovering new components of this enzyme almost ten years after it was discovered," said Steven Artandi, MD, PhD, assistant professor of medicine and senior author of the study. The work will be published in the March 21 issue of Cell.

Telomerase is best known for its role in maintaining the cell's genetic material, the chromosomes. Every time a person's cell divides, it makes a second copy of the 46 chromosomes, then sends one copy to each of the two resulting cells. As that copying process proceeds, each replication snips a bit off the protective tips of the chromosomes, called telomeres. Those ever-shortening chromosomes are one reason cells age
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