BAG2 organelle cleans cellular debris

[corybroo]

Newly recognized organelle that helps clean out cellular debris when the organism is stressed.

Scientists discover and characterize a novel membraneless organelle that could play a role in Alzheimer's treatment

Researchers in UC Santa Barbara neuroscientist Kenneth S. Kosik's lab have discovered a novel organelle—a previously unknown cell structure whose function it is to help clean up faulty proteins in times of stress and keep cells functioning in top condition. 

Of particular interest are biomolecular condensates, which don't have the recognizable cell membrane enclosure, but instead, are separated from the surrounding cytoplasm by a difference in density that can be loosely compared to a drop of oil in water. 

a stress granule is a membraneless organelle that appears when the cell is under stress … and its job is to sweep up RNA floating around in the cytoplasm, storing those genetic instructions and pausing their translation into proteins.

BAG2 condensate … is capable of sweeping up these faulty proteins in the cytoplasm and stuffing them into a proteasome—the cell's version of a trash can—located in the organelle.

what makes this particular proteasome (labeled 20S) special is that it can accept proteins that are already somewhat misfolded and would not fit in the other cellular trash cans.

Additionally, this method of protein degradation does not rely on the ubiquitination process, in which proteins meant for destruction are marked with a tiny ubiquitin protein tag before being grabbed by the proteasome.