A new role of RNA?

[Jordan14]

In the science community, often regarded as the predesesor of DNA and proteins, and often overlooked. Recent finding suggest that is more ncRNA than protein making RNA suggesting a bigger role for RNA. Has anyone got any opinions or more infomation on the subject.

 

I myself beleive that RNA deserves more recognition and shouldn't be veiwed as a subserviant messager.

[ashwini]

there seems to be a lot of talk going around about antisenseRNA these days....hope that wil lead to better treatment of RNA!!!!!!!!!!

[Sorcerer]

Antisense mRNA blocks mRNA by bonding to it so it cannot produce its protein.

 

Small nuclear RNA interference is a cool new tech. Look it up, I can't remember exactly how it works.

 

Protein is equally important for ribosomes these days, but RNA is the egg I choose coming first, although protein first hypotheses do have some weight.

 

Cellular machinery is DNA RNA PROTEIN, some of those can play dual roles like RNA has catalytic ability, however all 3 are necessary to make a modern cell.

[UCF-Forensic]

You know, this information would be good in another thread about defeating the AIDS virus....I unloaded my entire worldly knowledge on tRNA, mRNA and their role in transcription and translation, and this information here is very very interesting, as I have not studied antisense mRNA. Could I get a link to some good information??????

 

Also do you think this antisense mRNA could be a tool to help us fight AIDS??

[Sorcerer]

Yes I think that maybe a virus with antisense RNA to the DNA produced by the retrovirus itself could be a way to slow down the production of HIV proteins, maybe even a modified HIV could carry this antisense mRNA into the cell.

 

How ironic, using the virus to defeat itself.

[Sorcerer]

RNAi is similar to antisense mRNA, except it only bonds to a small peice of the mRNA, but still interfers with its processing, I think a problem with RNAi is that it could be too general and interfer with many proteins. RNAi is new to me however and I havent done any reading on it beyond New Scientist, so correct me if I'm wrong

[badchad]

I'm not familiar with RNAi. However I would think it would be fairly specific as it would only bind it's complementary strand. From the little that I know, my feeling is that antisense RNA isn't as effective as it theoretically could be. I tihnk one of the main problems is it's breakdown. The body will recognize the foreign material and break it down rather quickly. In addition you may need enough of the antisense RNA to block protein synthesis.

[Sorcerer]

If the antisense RNA was being produced by a virus similar to the HIV, then it would produce equal ammounts necessary, and mRNA breakdown should be similar for both.

 

I think RNAi is using small peices of RNA to bind to complementary sites on mRNA, but since its small it may bind to other mRNAs with similar codons, say it binds to ACUACCU this could be expressed in many mRNAs and it could have multiple unwanted effects.

[badchad]

Interesting, I was envisioning antisense RNA as simply be "added" to a person (e.g. via injection). In theory using a virus would be a better solution (although I don't know how you would "program" a virus to synthesize a particular piece of RNA). I'm ony familiar with antisense RNA being used in laboratory animals as a way to temporarily "knock out" a particular gene/protein. I guess the "size" of the piece of RNA depends upon the size of the protein/gene you want to control.

 

Interesting nonetheless...

[Sorcerer]

Well, a very scratchy method would be, use exonucleases to cut out the RNA which codes for a crucial gene in HIV, say HIV protease, then take the complementary strand of that RNA and insert it into the HIV virus using a transposon complete with promoters. Knock out all other crucial genes except those involving entry into the cell and reverse transcription. The patient would then be innoculated with the virus, and antisense mRNA would be produced to the mRNA of HIV protease.

 

Result-----> a reduction in HIV protease expression.

 

Possible problems: cancer if the virus inserts itself into the wrong part of the genome... however this is also a potential problem with HIV itself. Also HIV may exclude other viruses entering once it has inserted itself, via exclusion factors on the cells coat or other mechanisms preventing more reverse transcription (I'm not sure)

 

If it does use exclusion factors this may be a route for vaccination, make a HIV with only the exclusion factor expression.

[Bluenoise]

RNAi doesn't block a ribosome from translating mRNA per se.

It binds to the mRNA strand which causes machienery within the cell to mark it for being cut into smaller fragments. These smaller fragments produced actually act simular to the RNAi and have a kind of cascade chain reaction mechanism that silences the translation of the gene. Well that's at least how I remember it.

 

Nature has a good section on it acutally if you have time. With a really cool video.

 

here's the link for the animation.

http://www.nature.com/focus/rnai/animations/index.html

 

And here's the link for the main page of thier focus.

http://www.nature.com/focus/rnai/index.html

[Bluenoise]

As an added note I think that the biggest problem with RNAi use currently is directing it to the site of interest. It's in a long double stranded form originally I think. Injecting RNA into someones blood streem will not have any effect since it will not be take up by cells. Some sort of vector is necessary. I remember reading a paper earlier about linking it to a protein to facilitated transport across the cell membrane that got some results. A virus should work fine as well.

[Sorcerer]

Thx Blue, I'll read up on those, modern genetics and biotechnology fascinates me.

[Sorcerer]

interesting: In plants (and cultured insect cells), RNAi also has a role in antiviral defense, in which viral dsRNAs are targeted for destruction by the RNAi machinery.