Telomere Biology
We are taking biochemical, molecular genetic, and cell biological approaches to study the structure, function and maintenance of telomeres. Telomeres are higher order nucleoprotein complexes that cap the ends of eukaryotic chromosomes and play essential roles in conferring genome stability and cell proliferation capacity. The protective cap of the telomere is comprised of specific telomere binding proteins that regulate the telomeric DNA tract and allow the cell to distinguish the chromosome terminus from a double strand break. Telomeric DNA is maintained by the action of telomerase, an unusual ribonucleoprotein with reverse transcriptase activity. We have developed the genetically tractable model plant Arabidopsis thaliana as a system for studying telomere biology in higher eukaryotes. Arabidopsis displays a remarkably high tolerance to telomere dysfunction and hence has proven to be an excellent model for investigating the function of genes essential for telomere maintenance. Our current studies focus on the molecular consequences of telomere dysfunction, on the identification and characterization of telomere capping proteins, and on the structure and regulation of the telomerase RNP enzyme.