BioND — Dynamics of Biological Networks

Fusion of protein aggregates facilitates asymmetric damage segregation

Miguel Coelho, Stephen J. Lade, Simon Alberti, Thilo Gross, and Iva M. Tolic
PLoS Biology 12(6), e1001885, 2014.



During their lifetime, cells accumulate damage that is inherited by the daughter cells when the mother cell divides. The amount of inherited damage determines how long the daughter cell will live and how fast it will age. We have discovered fusion of protein aggregates as a new strategy that cells use to apportion damage asymmetrically during division. By combining live-cell imaging with a mathematical model, we show that fission yeast cells divide the damage equally between the two daughter cells, but only as long as the amount of damage is low and harmless. However, when the cells are stressed and the damage accumulates to higher levels, the aggregated proteins fuse into a single clump, which is then inherited by one daughter cell, while the other cell is born clean. This form of damage control may be a universal survival strategy for a range of cell types, including stem cells, germ cells, and cancer cells.

Media Coverage

Roland G. Roberts, PloS Biology Synopsis, 2014-06-17
We all pass unwanted stuff on to our children—emotional baggage, peculiar habits, unfashionable furniture. Cells do the same thing when they divide; along with their newly replicated genomes andthe vital cellular organelles, they also pass on a lifetime’s worth of accrued rubbish. An important component of this is the legacy of insoluble aggregated protein that the parent cell has failed to deal with by the normal processes of degradation, and the amount that’s passed on can affect the lifespan and wellbeing of the daughter cells.
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