The take home message is that we at one point had a gene that can block HIV infection. Somewhere along the way it got a mutation that produced a truncated protein. These guys found it, fixed the glitch, and showed that the resulting protein is effective at blocking HIV infection. They then took the next step of figuring out a way to "fix the glitch" in humans without using some complicated gene therapy approach. All in all, this is very impressive.
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[1] I'm assuming your mother isn't a committer to GCC :)
It is pretty bad, there's only a theoretical cream that may be in use some day, many years from now and it may reduce infection rates.
If you take the article at face value, we just cured HIV. And IMHO articles like that are VERY bad because over the years they have built a consensus of science is wrong and confusing and disappointing into the general public.
Anything that's repeatedly over hyped will end up like that.
> Given that the endogenous production of retrocyclins could also be restored in human cervicovaginal tissues, we propose that aminoglycoside-based topical microbicides might be useful in preventing sexual transmission of HIV-1.
That's a long long way from the sensationalist tone of the terrible linked article. We already have the above. (Condoms.)
Considering that the population most at risk for HIV/AIDS might be unwilling or unable to use condoms (sex workers), having more mechanisms for preventing the disease is a Good Thing.
The ability to reawaken retrocyclin genes from their 7 million years of slumber using aminoglycosides could provide a novel way to secure enhanced resistance to HIV-1 infection.
After 7 million years of no selective pressure, these genes have certainly accumulated mutations. I would put my money on the "resurrected" protein being completely useless.
The genome is full of random crap left over from the evolutionary process (including some things thought to have been captured from viruses). Who knows what kinds of selective pressure this section of the genome has been exposed to? It has obviously accumulated some amount of mutations, hence the premature stop codon.
It is important to note that the retrocyclin is correctly produced in old world monkeys, and the mRNA is created in humans (as a pseudo gene). So, the lack of selective pressure is a pretty recent event (evolutionarily).
So, this _is_ science, no 'technically' about it. PLoS is a top tier journal, and this looks very promising. So while this may not be a 'cure' for those with HIV, it could very well help people avoid an initial infection.
Who knows what kinds of selective pressure this section of the genome has been exposed to?
Probably none. You would be hard pressed to conjure up a reason to explain why a sequence that codes for a non-functional protein would be functionally conserved for 7 million years. (You could win a Nobel prize for such a revolutionary contribution.)
I work in drug design. Let me assure you that even a single mutation can render the structure of a protein completely inert.
There is also no reason why it wouldn't be conserved... perhaps it's in a highly conversed region? Without looking up exactly where it is in the genome, I wouldn't speculate. I'd be more interested in knowing how the sequences compared to chimp or orangutan.
I'm fully aware that a single mutation can render a protein inert. However, a different mutation might not have any effect. In this case, the mRNA is expressed as a pseudo-gene, so that's a good sign. The mutation is a nonsense truncation. With that problem 'fixed' and with a correctly translated protein, this protein might still work.
fascinating story.. kind of a blemish that the article contains an error:
a virus which can't get into cells is just a scrap of amino acids waiting to be destroyed.
To the best of my knowledge, viruses do have DNA, if very little. That is in fact the reason they need to enter the host's cells - they need access to the DNA reproduction machinery inside to make copies of themselves.
DNA is made of amino acids. If the DNA can't get into a cell, it's useless as DNA and is only good for digestion into amino acid building blocks for some other protein.
"DNA is made of amino acids. If the DNA can't get into a cell, it's useless as DNA and is only good for digestion into amino acid building blocks for some other protein."
No, just totally, absolutely 100% wrong. If you voted this comment up, please smack yourself for voting up things that merely sound authoritative. Thank you.
Proteins are made of amino acids. DNA is made of deoxyribonucleotides. They're nothing alike. Proteins are translated from the information in RNA, which is a minor variation of the information in DNA. Think of proteins as molecular machines that are made from the instructions in DNA, and you're closer to the truth.
The funny part is that when I first read this comment, the wrong post (GP) had -1 points. Now it's +1. That's two people smacking themselves. Congratulations.
On a side note: this brings up a great XKCD quote: "Someone is wrong on the Internet". (http://xkcd.com/386/)
Even having read a few popular science books a few years ago (50-year DNA anniversary), it's been too many years since AP Biology. Could you/ others please recommend a few titles (articles, books, titles), at the AP Biology level, on (a) proteins and RNA, (b) genes and DNA ? Thanks in advance!
