Lisa Timmons

ABC transporters and RNAi: anti-foreign genome responses and stem cell regulation.

We are studying RNA silencing mechanisms. These are cellular machineries with diverse actions that are guided by the sequence information in non-coding RNAs. These activities are vital to cells, protecting them from invasion by viruses and from mobilization of transposons. They also play important roles in development and cancer, allowing for fine-tuning of gene expression. In RNAi experiments, these cellular mechanisms are activated when dsRNA is delivered to cells and organisms, which allows for sequence-specific alteration of gene expression. Work on this funded project includes:

The role of ABC transporters in RNAi.
We uncovered a role for ABC transporters in RNA silencing mechanisms and in transposon silencing. This finding highlights a potential connection between environmental signaling and RNA-directed epigenetic mechanisms that control gene expression and maintain genome integrity. ABCRNAi transporters interact genetically with conserved RNA silencing mechanisms and genes implicated in cancer. We are utilizing a variety of genetic, cell biology, and biochemistry techniques to elucidate the role of ABC transporters in RNA silencing. We are particularly interested in their roles in the development of the germ line, the ultimate stem cell.

Improvements in RNAi efficiency.
Previously, we developed an ingestion-based bacterial dsRNA delivery system. We are continuing to work on methodology that will allow for improvements in RNAi-mediated gene silencing.