CAMBRIDGE, Mass.--MIT biologists have identified a mechanism of aging in yeast cells that suggests researchers may one day be able to intervene in, and possibly inhibit, the aging process in certain human cells.
The mechanism of aging, it turns out, is elegant in its simplicity. During a yeast cell's life, whenever a particular, coiled piece of DNA pinches off from one of its chromosomes, that extrachromosomal ribosomal DNA (ERC) replicates until the cell becomes overwhelmed and dies. Aging in yeast cells is started by the formation of that first ERC.
"The best part is, it's obvious it's a clock," said Leonard Guarente, Professor of Biology, referring to the ERCs' role in yeast cell mortality. "Set the clock early and the alarm rings early."
An article to be published in the December 26 Cell culminates a year's published work on this topic (articles appeared in Cell, Science and now Cell, again). The piece, co-authored by David A. Sinclair, a postdoctoral fellow in biology at MIT, and Professor Guarente, also communicates the researchers' enthusiasm for the work, with an overtone of wonder at its broad implications and precise beauty.
"It is remarkable that this mechanism of aging in mother yeast cells is so simple at a molecular level," the biologists wrote. "It is conceivable that inhibitors of this (aging) process can be found and if so, such strategies might eventually prove useful in forestalling aging in yeast and, perhaps, in higher organisms."
The discovery of the simple role of ERCs in cell aging and death has a
profound appeal well beyond the laboratory. Indeed, William Shakespeare, a man
of powerful intuition and observation, would be pleased to learn how closely
Hamlet's phrase denoting mortality -- the "mortal coil" -- portrays an actual
molecular drama. A drawing of ERCs in action shows that an aging yeast mother
cell is full
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Contact: Sarah H. Wright
shwright@mit.edu
617-258-5400
Massachusetts Institute of Technology
26-Dec-1997