Journal of Bioequivalence & Bioavailability

Abstract

Regulation of microRNA Functions by Non-coding RNAs

Zina Jeyapalan and Burton B. Yang

Recently, there has been an increased interest in the function of non-coding RNA transcripts. The term non-coding RNA (ncRNA) is given to a functional RNA molecule that is not translated into protein. Originally non-translated regions of the genome were considered "junk DNA" based on the fact that they did not code for proteins and were thought to serve no purpose. However, their importance has been revealed in recent years. The 3'untranslated region (3'UTR) is an example of a type of ncRNA. The impact of the 3'UTR on miRNAs was originally introduced by our laboratory. We hypothesize that in the presence of the 3'UTR, endogenous miRNAs would bind to sites on the 3'UTR when the binding affinity is sufficiently high. This would arrest the normal function of the endogenous miRNAs and free the potential targets (mRNAs) of these miRNAs. As a consequence, the freed mRNA will be translated to proteins. The effect of the 3'UTR on miRNAs is naturally occurring in the form of pseudogenes. These pseudogenes are an important component of the genome because they have been discovered to be as abundant as functional genes. It has been estimated that there are approximately 20,000 putative pseudogenes in the human genome [1]. This was recently described by Poliseno and coworkers, in which a PTEN pseudogene, PTENP1, was discovered to regulate PTEN cellular levels and suppress growth.