Research interests
A typical cell contains thousands of different mRNA species whose lifetimes can differ from a few minutes to several hours or days. Furthermore, it has been found that lifetimes of individual mRNA populations can be up- and down-regulated by internal and external cues. Despite its importance for determining levels of transcripts and of gene expression, the molecular basis for differences in lifetimes of mRNAs is largely unknown. Sequence elements important for stabilizing or destabilizing transcripts have been found in 5’ and 3’ untranslated regions of mRNAs but how these elements function in controlling RNA longevity remains elusive.
We have delineated short RNA-stabilizing sequences near the 5’ terminus of mRNAs in chloroplasts and showed that these sequences have to fold into a specific RNA secondary structure in order to function in RNA stabilization. Mutations in the 5’ region of mRNAs that prevent folding of the sequences into their native conformation render the transcripts extremely unstable.
Currently our research centers around the identification of putative trans-acting factors that we believe bind to the RNA-stabilizing sequence elements. We are also trying to characterize the molecular machinery that degrades mRNAs in chloroplasts.