With all of the big energy conservation campaigns over the years, not many people understand flipping-switches like Southern Californians. You can’t get through a Lakers game without being reminded to turn the lights off, or adjust your thermostat. It appears that some researchers from the Institute of Microbiology in Prague have gotten into the act as well, finding that RNA binding proteins (RBPs) have been “flipping the switch” on miRNA regulation all along!
This research effort tackled the question of miRNA kinetics in mRNA downregulation through mathematical modeling.
- First, they developed a model of miRNA action based on binding to mRNA accounting for both mRNA downregulation and miRNA decay.
- They applied their model to previously published microarray data generated from HepG2 cells transfected with miR-124a – their analysis revealed two distinct classes of mRNA decay kinetics, including a novel “on-off” digital switch mechanism in addition to more well known, graded response.
- Finally, they identified 3’UTR-binding proteins that seem to mediate mRNA downregulation by blocking miRNA target sites as they bind, creating this novel miRNA on/off switch mechanism.
The kinetics of miRNA regulation is still a wide-open field – the authors themselves acknowledge their work is “the first attempt to quantify the kinetics of free miRNA concomitantly with the effect on the downregulation of target mRNAs.”
See if their model leaves your switch in the “On” position at Nucleic Acids Research, April 2010.