Research Summary

Interplay between effector and regulatory T cells in the pathogenesis of intestinal inflammation.

oth miRNA under-and-over-expression can cause developmental abnormalities and human diseases as deadly as cancer can result, but nothing about the pathway and the modus operandi of the miRNA turnover process in animals is known except the involvement of a few 'miRNases', which have only recently been shown to be crucial for modulating miRNA abundance-and-activity. Now, most eukaryotic nucleases reside in complexes, in the milieu of co-factors, which direct their action towards specific substrates, and the nuclease-activities often get regulated by means of those co-factors. XRN-1/2, implicated in the miRNA turnover in Caenorhabditis elegans are also known for the processing and turnover of a variety of different RNA substrates in various pathways. Therefore, it is also likely that these nucleases are associated with defined sets of co-factors which direct them to those pathways, determine their specificities, and achieve responsiveness to regulatory cues to bring about different physiological outcomes. And this possibility is bolstered by the observation that endogenous XRN-1/2 in Caenorhabditis elegans predominantly reside in high molecular weight complexes rather than as 'individual species'. Thus, understanding the mode of action of the 'miRNA turnover complexes' (miRNasomes), rather than the individual 'miRNases', would be one key step to unravel miRNA turnover pathway.