MicroRNAs: The Key Regulatory Molecule and the Evidence of Cross-Kingdom Regulation

摘要

In plants, the microRNAs are mostly employed in the development and defense processes and functions as negative regulators of gene expression by targeting mRNAs for cleavage or translational repression. Recently, an exogenous plant microRNA MIR168a is reported to specifically target mammalian Low Density Lipoprotein Receptor Adapter Protein 1(LDLRAP1) mRNA (Zhang et al. 2012). This finding was confirmed by the fact that plant miRNAs are 2'-O-methy! modified at their 3’ end, which makes them resistant to sodium periodate, whereas human miRNAs have free 2’ and 3’ hydroxyl groupmaking them sensitive to sodium periodate (oxidizing agent). Also, experimental animals having diet rich in plant sources are found to have high level of exogenous plant miRNA in their serum.