Saturday, September 23, 2006

Of linen and proteins...

And stressful situations in closets and cells.

I've mentioned before that I suffer a weense from disposophobia or the inability to part ways with stuff. Old towels are no exception. My linen closet bulged (past tense due to recent reform efforts) with tattered towels and sheets too short for current mattresses. As I dug deeper in search of bath accessories with the most residual fluff, the rifled remaining towels took up more and more space, threatening the hinges on the closet doors. I desperately needed an unfolded towel response (UTR).

Enter the towel-like equivalent of body clutter, namely unfolded proteins. Not only do your cells need to string the appropriate sequence of amino acids together to form proteins, but they also must pull a little proteinaceous origami trick to get them into the right spatial configuration for proper functioning. Unfolded proteins are the bane of an aging cell's existence--witness all that rumpled beta-amyloid protein that gums up old neurons in Alzheimer's disease.

Hurrah for evolution! Enter the unfolded protein response (UPR), nature's way of sensing a haphazard pile of proteins on the cellular floor. And if the UPR can't straighten up the protein closet--wadded proteins stacking ever higher--then the UPR just makes some sort of nasty enzyme that explodes that cell and its proteiny mess right then and there.

Alas, as Dr. Dale Bredesen of the Buck Institute for Age Research points out, the UPR is no different than a lot of other body responses to dysequilibrium: "The initial response is protective, but the late response is destructive." He and other neurobiologists are hoping to unlock the secrets of UPR in order to keep this organizing principle on our side.

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