hi Gaurab

Ago1 is Required for RNA-mediated gene silencing (RNAi) . Binds to short RNAs such as microRNAs (miRNAs) or short interfering RNAs (siRNAs), and represses the translation of mRNAs which are complementary to them.This is in Human.

Regards

Jamuna Yadhav R

Thanks for replying.

I am more concerned on the fate of a small RNA inside nucleus apart from the RNAi driven silencing.

Transcriptional gene silencing(TGS) which causes histone methylation led by AGO1-siRNA influence.

With regards,

Gaurab

Hi

I think its also required for transcriptional gene silencing (TGS) of promoter regions which are complementary to bound short antigene RNAs (agRNAs). its said that Ago protein guides the agRNA to its promoter target, which can be non-coding transcript overlapping the promoter or the chromosomal DNA. Ago proteins then recruits histone modifying enzymes such as histone methyltransferase to the promoter to activate transcription by causing permissive epigenetic changes.

am not quite clear about your query. this is what i have read about Ago proteins.

Regards

Jamuna Yadhav R

hi

Some info about Ago 1

Molecular Function:

protein binding; nucleic acid binding; RNA binding; translation initiation factor activity

Biological Process:

regulation of translation; regulation of transcription, DNA-dependent; miRNA-mediated gene silencing, negative regulation of translation; RNA-mediated gene silencing

I got this info from http://www.phosphosite.org/proteinAction.do?id=5142671&showAllSites=true

may be you wanna explore that site and get few papers

Regards

Jamuna Yadhav R

Thanks for this useful link. I am going through the link sent.

My basic idea is that are their any natural cases of tsg reported with connection to other sources of naturally found small RNA like miRNA (the ones which get imported to nucleus) or the dsRNA viruses which their marks in

cells and can act as dicer substrate.

I hope I could make you clear of my idea.

Thanks and regards,

Gaurab

search for siRNA interactions in plants rather than in animals as you know miRNAs processing in animals takes place outside the nucleus. In plants the processing of mature miRNA is done by DCL1 inside the nucleus therefore you may find the more resources and/or experiments in plants . Try searching in GEO (www.ncbi.nlm.nih.gov/geo/) or SRA for NGS or other related data and experiments.

DNA methylation mediated by a microRNA pathway

http://www.ncbi.nlm.nih.gov/pubmed/20381393

Transcriptional Control of Gene Expression by MicroRNAs

http://www.ncbi.nlm.nih.gov/pubmed?term=Transcriptional%20Control%20of%20Gene%20Expression%20by%20MicroRNAs

I am already following some of the citations on arabidopsis. I will be imteresed to collect more citations.

Anyways thanks for replying.

Thanks for sending these publications Dr Wang. This is exactly what I was looking for.

Thanks once again I shall get back to you after reading them.

Regards,

Gaurab

[email protected]

Sure.it does the performance on gene signalling on post transcriptional level or early translational level..

Yes. Ritu u r right. It is a downregulator in some pathways. Example: cardiovascular physiopathology...

I don't know about miRNA but I noticed in a transcriptomic study of the silencing effect of siRNA that most of the down regulated genes had homology at the DNA but not on the mRNA level. Further studies will be of course needed to make conclusive statement.

Dear Sathya and Ritu,

Thanks for your replies. I am attaching a work published with respect to nuclear miRNA. Hope you will find it interesting.

My interest is not only that but I would like to know if transcriptional gene silencing by histone methylation.

There is a role of AGO1 in guiding the small RNA to the promoter region.

The silencing so achieved is a longer period than any other form of post transcriptional silencing.

http://www.springerlink.com/content/n701wt00m8184822/

Thank you Dr Dever. I find this very interesting. I had heard about lmiRNA before I guess but never read much of citations. It will be great if you can send me some cited refereces of this pathway. DCL3 splicing and loading of AGO4 is a new concept. But the question is that is the phenomenon evoking epigenetic changes as it happens in TGS led by siRNA antisense strand.