All multicellular animals produce enzymes that can alter the sequence of their own RNA molecules. The biological roles for such “RNA editing” include: correcting errors in mitochondrial DNA sequences; regulating cholesterol metabolism; and producing multiple forms of receptors for various neurotransmitters. I am interested in the biological roles for a family of enzymes called “Adenosine deaminases that act on RNA” or “ADARs”. These enzymes convert adenosine (A) to inosine (I) within double-stranded regions of RNA.
ADARs contribute to protein diversity by producing codon changes within messenger RNAs (mRNAs). This allows cells to synthesize multiple forms of a protein from a single mRNA. This function seems to be particularly important in the nervous system where ADARs are highly expressed and where several ADAR substrates have been identified.
To further understand ADAR function, I developed a method to systematically identify ADAR substrates. By finding where this reaction occurs, the hope was to gain insight into why it occurs. I found a large number of edited RNAs in both human brain and a small worm called C. elegans (see publications below). Unlike previously discovered ADAR substrates each of these mRNAs was edited in a non-coding region (3’ UTR, 5’ UTR, or intron). The challenge now is to understand the biological consequences of this type of RNA editing.
I am currently developing a new technique for detecting inosine. If successful, this method can be used to detect not only inosine, but any small molecule of interest. Thus, this research could have applications in many areas including environmental chemistry, forensics, and diagnostics. This project (outlined below) utilizes many modern molecular biology and biochemical techniques including: oligonucleotide synthesis, in vitro transcription, column chromatography, RT-PCR, and fluorometry.