A. Education
The University of Chicago BA 12/75 Biology
The University of Chicago PhD 06/81 Biochemistry
The University of Chicago Post Doc 1981-1985 Molecular Genetics
California Institute of Technology Res. Fellow 1985-1987 Biochemistry
B. Positions
Positions and Employment
1987-1996 Assistant Member, Program in Molecular Biology, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center
1987-1996 Assistant Professor, Sloan-Kettering Institute Division, Graduate School of Medical Sciences, Cornell University
1996-1997 Associate Professor, Department of Biochemistry, Tulane University Medical School, Tulane University HSC
1998-2005 Associate Professor (tenured), Department of Biochemistry, Tulane University Medical School, Tulane University HSC
2005-Present Professor, Department of Biochemistry, School of Medicine, Tulane University HSC
2005-2006 Visiting Professor, Department of Molecular Biology and Cell Biology, Northwestern University
2012-2013 Chair, Departmental Faculty Search Committee Adjunct Faculty
2002-Present Adjunct Faculty, Department of Human Genetics
2009-Present Member, Tulane Aging Center
Role of telomere dynamics in chromosome stability and transcriptional regulation
The integrity of the telomere nucleoprotein structures at the end of eukaryotic chromosomes is essential for genomic stability. Telomeric structures must both accommodate the end-replication problem and serve as a buffer against promiscuous nuclease and recombination activities. While most eukaryotes utilize the ribonucleoprotein telomerase for the addition of simple sequence repeats, alternative recombination-based pathways (ALT) exist in both yeast and vertebrates. In humans, ALT pathways are responsible for immortality in 15% of tumors. Our long-term goal is to increase our knowledge of the mechanism, efficiency, and regulation of telomere/telomere recombination that will ultimately provide the means for its manipulationThis information will be critical for the control of the ALT pathway of telomere addition in humans.
Our laboratory has investigated the structure and replication of telomeres using yeast Saccharomyces cerevisiae as a genetic model system. Telomeres are the structures present at the termini of eukaryotic chromosomes composed of G+T-rich DNA and a plethora of proteins that allow complete replication of the telomere and protection against factors that can act to degrade chromosomes. We have been exploring several novel aspects of telomere function. Multiple studies have implicated defects in telomeres and the onset of oncogenesis and chromosomal catastrophe. While most eukaryotic telomeres are replicated by the reverse transcriptase telomerase, we have focused on the second recombinational mode of telomere addition and deletion, both of which are highly maintained in vertebrates. Some protein complexes involved in this recombination pathway are present exclusively at the telomere while others are present both in replication and DNA repair. Using alleles of mutations in gene that encode components of these complexes, we have investigated the mechanism of telomere recombination. These studies have led to the discovery that telomeres have an epigenetic and heritable component. These latter finding provides a completely novel view of telomere regulation in yeast and in vertebrate oncogenesis.
Dynamics of yeast telomeres as related to sesescence
