Hello ; I know this one.

miRNA-mRNA target site interaction rule.

MicroRNAs (miRNAs) interact with their mRNA targets by base pairing. In plants, most miRNAs base pair to mRNAs with nearly perfect complementarity and induce mRNA degradation by an RNAi-like mechanism — the mRNA is cleaved in the middle of the miRNA–mRNA duplex. By contrast, with few exceptions, metazoan miRNAs base pair with their targets imperfectly, following a set of rules that have been identified by experimental and bioinformatics analyses.• One rule for miRNA–target base paring is perfect and contiguous base pairing of miRNA nucleotides 2 to 8, representing the ‘seed’ region (shown in dark red and green), which nucleates the miRNA–mRNA association. GU pairs or mismatches and bulges in the seed region greatly affect repression. However, an A residue across position 1 of the miRNA, and an A or U across position 9 (shown in yellow), improve the site efficiency, although they do not need to base pair with miRNA nucleotides.• Another rule is that bulges or mismatches must be present in the central region of the miRNA–mRNA duplex, precluding the Argonaute (AGO)-mediated endonucleolytic cleavage of mRNA.• The third rule is that there must be reasonable complementarity to the miRNA 3′ half to stabilize the interaction. Mismatches and bulges are generally tolerated in this region, although good base pairing, particularly to residues 13–16 of the miRNA (shown in orange), becomes important when matching in the seed region is not perfect match.

But the rules did not all kind of mirRNA-target interaction

Two recent studies using immunoprecipitation of miRNA-containing ribonucleoprotein complexes indicate that only 30–45% of miRNAs associated with these complexes contain perfectly matched, conserved seed elements in their 3' UTRs13, 14. There is thus a need for target prediction algorithms that accurately incorporate modified 5' seed rules.

Thanks a lot...but I still don't understand if the miRNA:miRNA* duplex enters the RISC as it is or it is being cleaved by a helicase-like enzyme before its entrance. I mean it enters as a duplex or as a single strand to the RISC

Thanks .. never mind, I will try to search for it as soon as I got time..

Can anyone tell me what they feel about the idea of patenting microRNAs

Patenting miRNAs..wow!!

I dont know is there any process/protocol for this or not. But Lets suppose i discover a novel miRNA..does it make me eligible for patenting this miRNA. In case of developing artificial miRNAs it seems more obivious..its your design and you can patent it...Looking for more facts from all you guys.

You Can not patent a discoverable thing..You can just patent what you have made .. a new novel thing..

Check out http://www.nature.com/natureevents/science/events/47533-microRNA_Analysis_Using_Next_Generation_Sequencing