News: Various species' genes evolve to minimize protein production errors.
Ye Old One
http://www.eurekalert.org/pub_releases/2008-07/hu-asg072208.php
Previously unexplained patterns of evolution may aim to prevent or
tolerate mistranslation
CAMBRIDGE, Mass. -- Scientists at Harvard University and the
University of Texas at Austin have found that genetic evolution is
strongly shaped by genes' efforts to prevent or tolerate errors in
protein production.
Their study also suggests that the cost of errors in protein
production may lie in the malformed proteins themselves, rather than
the loss of functional proteins. Misfolded proteins can build up in
long-lived cells, like neurons, and cause neurodegenerative diseases.
The work, by D. Allan Drummond at Harvard and Claus O. Wilke at Texas,
is described in the July 25 issue of the journal Cell.
"It has long been believed that the main force of natural selection on
protein-coding genes is the need to maintain a working protein," says
Drummond, a Bauer Fellow in Harvard's FAS Center for Systems Biology.
"Our work suggests that another force may be equally important: the
need to avoid misfolded proteins resulting from errors in
translation."
Protein molecules must fold to become biologically active, and
mistakes can cause misfolding, which can be toxic. Yet the
protein-producing factories in our cells are estimated to make
mistakes in 20 percent of the molecules they produce. Adaptations to
this surprising sloppiness may be crucial in understanding the
evolution of genes across species, from bacteria to humans, say
Drummond and Wilke.
Essentially, they write, natural selection has fostered the evolution
of genes that minimize the effects of errors in translation, the
production of proteins from genetic templates in cells. An example is
the careful placement of codons, which are sections of DNA that code
for amino acids, the building blocks of proteins. Some codons
translate more accurately, and previous research had suggested that
high-fidelity codons are positioned at key locations in the genome,
where a mistake might be harmful. These studies, however, had only
considered fast-growing organisms like E. coli bacteria and fruit
flies.
"Contrary to what was believed, our work shows that even in the human
genome, codons are positioned to minimize errors," says Wilke,
assistant professor of integrative biology at Texas. "Just like a
mistake on your taxes is more costly than a mistake on your grocery
list -- so you concentrate more on your taxes -- cells seem to
concentrate on preventing mistakes that might result in costly
misfolded proteins."
Drummond and Wilke analyzed humans, mice, fruit flies, worms, yeast
and E. coli bacteria and discovered that all of these organisms have
evolved ways to prevent the production of costly aberrant proteins.
"Finding such sweeping effects from a single, simple cost has the
potential to reshape the way evolution is studied at the molecular
level," Drummond says. "While much work has focused on how evolution
makes creatures different, our work emphasizes fundamental ways in
which all life is the same."
While evolutionary studies are often retrospective, Drummond and Wilke
also developed a molecular-level evolutionary simulation, allowing
them to track the evolution of genomes encoding many simple proteins
over millions of generations. In some simulations, they added
evolutionary costs for misfolded proteins, while in others this cost
was not factored in. They found that genomes evolving with misfolding
costs developed all the genome-wide patterns seen in real organisms,
while those evolving without costs did not.
The work could have long-term implications for our understanding of
neurodegenerative diseases. Misfolded proteins are known to accumulate
in neurons and are central players in fatal disorders such as
amyotrophic lateral sclerosis, better known as Lou Gehrig's disease.
Drummond and Wilke suggest that mistranslation may contribute to
long-studied forms of ALS and other similar diseases.
Wilke says the current study may lead to better ways to detect genes
with mutations that lead to production of toxic, misfolded proteins,
and ultimately, to a better understanding of neurodegenerative
disease.
"These genes may produce proteins that look innocuous but nevertheless
cause a severe disease condition," Wilke says.
###
Drummond and Wilke's work was funded by the National Institutes of
Health.
--
Bob.
spintronic
And you call me a quote minner.
spintronic
You do realise what you are saying, Right?
In a nutshell.
A gene is read, transcribed, translated, and then the ribsome fucks up
20% of the time.
So you have all these chaperones and error correction proteins to
"fix" these fuckups.
Which came first?
The Gene? The DNA?
All the proteins that transcribe the DNA (BUT their buggered)?
All the genes that translate the DNA (BUT their buggered)?
All the chaperones, that guide the process (BUT their buggered)?
All the ribsomes that BUGGER UP (BUT their buggered)?
You are compounding this Buggered up 20% quite a lot.
Did you realise that? Ore do you just quote mine?
GCPAXS...@spammotel.com
A "quote mine" in the context of t.o is a misleading quote.
Quoting the whole article can hardly be misleading, as all
the context is present.
About the "buggeredness": I understand the article to imply
that evolution works (and has worked) to minimize the effects
of it.
Query for IDists: why would an intelligent designer design
a translation function that has a 20% error rate?
Regards,
Karel
--
If knowledge can create problems,
it is not through ignorance that we can solve them (Asimov)
spintronic
Ah right, let me log that down. Whole articles are "good", partial
ones are "bad".
> About the "buggeredness": I understand the article to imply
> that evolution works (and has worked) to minimize the effects
> of it.
Wooo. If 20% degradation is with all the error correction in place,
how much without it?
> Query for IDists: why would an intelligent designer design
> a translation function that has a 20% error rate?
Idiot.
Thats like asking,
"Why would "quickpar" design an internet that has inherent signal
degradation".
Ye Old One
<spint...@hotmail.com> enriched this group when s/he wrote:
>And you call me a quote minner.
No, I call you an illiterate idiot.
--
Bob.
GCPAXS...@spammotel.com
If you log it down, you would be logging down an error:
"misleading" is an integral part of the definition; so, to avoid
errors,
that should become "a misleading part of an article". Obviously,
the *whole* article can't be "a misleading part", but I'll spell it
out
anyway, as you seem to have missed it the first time around.
And I am just surprised at the high error rate in a cell, something
the ID crew posits as designed (such complexity!). But perhaps
protein production is not important enough to be a design focus.
Cory Albrecht
> On Jul 24, 10:58 pm, Ye Old One <use...@mcsuk.net> wrote:
>> Various species' genes evolve to minimize protein production errors
>>
>> http://www.eurekalert.org/pub_releases/2008-07/hu-asg072208.php
[...entire original article snipped for brevity...]
> And you call me a quote minner.
Quoting the entire article is not quote mining. It's the exact opposite.
Quote mining is the practice of selective quoting to make it look like
the author said something they didn't actually say. The can be
accomplished by quoting a single sentence or sentence fragment without
the surrounding text which would provide necessary context. Another
tactic is to use ellipses to either falsely join two phrases to create
apparent context or to skip over phrases which would establish context
and show the quoter's error.
Nick Keighley
> On Jul 24, 10:58 pm, Ye Old One <use...@mcsuk.net> wrote:
> > Various species' genes evolve to minimize protein production errors
>
> >http://www.eurekalert.org/pub_releases/2008-07/hu-asg072208.php
<snip>
> > --
> > Bob.
you shouldn't quote sigs
> You do realise what you are saying, Right?
>
> In a nutshell.
>
> A gene is read, transcribed, translated, and then the [ribosome] fucks up
> 20% of the time.
>
> So you have all these chaperones and error correction proteins to
> "fix" these fuckups.
>
> Which came first?
>
> The Gene? The DNA?
chicken and egg. They co-evolved
> All the proteins that transcribe the DNA (BUT their buggered)?
you mean "they are" which may be abbreviated "they're"
> All the genes that translate the DNA (BUT their buggered)?
genes that translate the DNA?
> All the chaperones, that guide the process (BUT their buggered)?
> All the ribsomes that BUGGER UP (BUT their buggered)?
>
> You are compounding this Buggered up 20% quite a lot.
>
> Did you realise that? [Or] do you just quote mine
you have *twice* been told what "quote mining" means.
He isn't "quote mining" he's *quoting*
Why don't you just say what you mean?
Do you mean "I don't see how this system could have
evolved"?
It is kind of impressive that such a Heath Robinson
contraption can function so well
--
Nick Keighley