Ageing cells lose protein pumps
July 26th, 2010 - 3:38 pm ICT by ANILondon, July 26 (ANI): Scientists may have found why yeast cells, and perhaps the cells of other organisms, are not able to go on producing copies of themselves forever.
Yeast cells, much like our own cells, have a finite ability to reproduce themselves.
A ‘mother’ cell can only produce 20-30 ‘daughters’ before it loses the ability to replicate and dies.
Multidrug resistance (MDR) proteins are best known for helping cancer cells expel anticancer drugs.
Rong Li and colleagues at the Stowers Institute for Medical Research in Kansas City, Missouri, found that yeast lacking certain MDR proteins have a shorter reproductive lifespan; they produce fewer daughter cells.
Yeast engineered to contain more of these pumps, however, can produce more daughters.
Li and her colleagues found that yeast division also results in an unequal distribution of MDR proteins.
The mother cell retains the original MDR proteins while the bud gets young, newly formed MDR proteins. Because the mother’s supply is never replenished, she has to rely on the pool of MDR proteins that she’s born with, Li says.
Over time these proteins decay. Some lose only part of their function; others may stop working altogether.
We started to get the idea that “maybe these proteins are what’s limiting the lifespan of these cells,” Li says.
The team tested the idea that if the loss of MDR proteins does contribute to ageing, then cells that can’t make these proteins should have shorter lifespans.
MDR proteins help rid cells of toxins, so as they begin to fail, toxins could accumulate even faster.
The study “raises the intriguing possibility that a similar mode of regulation could influence stem-cell senescence during human ageing,” Nature quoted Matt Kaeberlein, at the University of Washington Medical School in Seattle, who investigates longevity in yeast, worms and mice, as saying.
It might also help explain why cancer cells, many of which are stuffed with MDRs, are seemingly immortal.
The latest study is published today in Nature Cell Biology. (ANI)
- Cancer cells' survival mechanism identified - Apr 27, 2011
- Mechanism limiting scar formation discovered - Jun 11, 2010
- Researchers discover mechanism that limits scar formation - Jun 12, 2010
- How loss of key protein promotes aggressive form of leukaemia - Jul 02, 2010
- Why some cancers become malignant and others don't - Jan 07, 2011
- Protein key to storing long-term memories - Jan 29, 2012
- Bile may harbour human Fountain Of Youth - Sep 16, 2010
- 'Glowing' plant cells that could control cell growth, death - Nov 01, 2010
- Motor protein that blocks ovarian tumor growth found - Apr 27, 2011
- Key target of aging regulator found - Jun 11, 2009
- Key enzyme in melanoma cell development found - Jun 18, 2010
- Biophysicist attempts to block protein to prevent breast, prostate cancer - Apr 20, 2011
- 'All cancer cells are immortal' theory exposed as a myth - Apr 22, 2011
- Aging-related protein holds breast cancer clues - Jan 28, 2011
- Key blood component produced from GM rice - Nov 06, 2011
Tags: anticancer drugs, bud, cancer cells, cell senescence, daughter cells, decay, intriguing possibility, kansas city missouri, lifespan, longevity, mother cell, organisms, protein pumps, proteins, stem cell, stowers institute for medical research, toxins, university of washington medical school, washington medical school, yeast cells
