Comments on: Return of Mad Cow Memories

By: Ann

Ann — Sat, 09 Jul 2005 23:23:44 +0000

Given that it took 20+ years for the prion hypothesis to be accepted in the first place, and given that it was only indisputably demonstrated recently that prions - without nucleic acids - act as infectious agents, I think a more patience is warranted. Two years is the blink of an eye in a molecular biology lab.

By: Torbjorn Larsson

Torbjorn Larsson — Wed, 06 Jul 2005 18:56:09 +0000

“the memory that makes you go mad.”

Even worse - it’s also the memory that you will keep in the grave.

By: wolff

wolff — Wed, 06 Jul 2005 14:39:45 +0000

I am confused about your statement of, “When a normal protein misfolds and becomes a prion….” Are you saying that other proteins can become a prion protein? I thought prion was the term given to the protein itself, not a class of proteins that behave like the prion protein. I was under the impression that there is only one “prion” protein, regardless of its folding. The prion protein (i.e. the protein in BSE) has two forms. The normal form is typically termed PrPC for “cellular.” The misfolded form is termed PrPSc for “scrapie.”

On a second note, knockout studies on PRNP have already been done. Strangely there is little affect on the mice (it did affect circadian rythms), leading some to conclude that whatever the prion protein does, there must be redundancy in the cell. These studies are under question now because knockout of the PRNP gene caused upregulation of a protein downsteam known as Doppel, which has some structural characteristics of the prion protein. And the saga continues…..

By: Henry Astley

Henry Astley — Wed, 06 Jul 2005 14:03:52 +0000

Oh dear, it’s the a scifi plot: the memory that makes you go mad.

Or an H.P. Lovecraft novel. Can we re-name the gene “Cthulhu”?

By: Ben Hyde

Ben Hyde — Wed, 06 Jul 2005 04:22:29 +0000

Oh dear, it’s the a scifi plot: the memory that makes you go mad.

By: mccm

mccm — Wed, 06 Jul 2005 04:08:08 +0000

Surely that second study looking for PrP polymorphisms wasn’t suggesting that when the protein goes into prion-mode it encodes a memory, which is what Lindquist and Kandel were arguing in 2003 for CPEB. We already know what happens when PrP goes into prion-mode and it is not good for memory. The CPEB story is quite intriguing, but its also interesting to keep in mind that there are plenty of mechanisms for making a protein permanently different outside of the sensational prion mechanism (i.e. post-translational modifications, degradation of regulatory subunits, or even regulation and processing that alters the initial structure of new copies of that protein). I suggest you look up PKMzeta or CaMKII autophosphorylation for examples. I don’t want to sound too suspicious, but the lab that put out that initial prion story already has the media’s ear in a major way and that may be why they were able to get a less than perfect story out so quickly. BTW, the acronym is misspelled in the last paragraph :).