Description of Research:

    The chromosomes within animal and plant cells are continually engaged in a cycle of DNA damage and repair. One common type of damage involves breakage of one or both strands of the DNA double helix. This type of DNA damage is particularly prevalent after exposure of cells to agents such as X-rays or radon gas and is also induced by many chemicals used in cancer chemotherapy.

    Restoration of the broken DNA double helix requires the coordinated activities of a large number of cellular proteins. The laboratory is applying modern techniques of molecular biology and biochemistry to identify and characterize genes involved in repair of strand breaks and other types of DNA damage. Several genes identified in this work have been found to affect other aspects of DNA metabolism, including cell cycle checkpoint responses and telomere stability. Furthermore, a subset of genes encode proteins homologous to human proteins previously implicated in a number of human diseases including cancer. Understanding these processes and the multiple pathways involved in DNA strand break repair are major goals of current research in the lab.

    A second major effort in the lab involves the study of cellular aging. Most human cells stop producing Telomerase, a DNA polymerase enzyme, early in development. Both in vivo and when grown in culture, telomerase-deficient cells undergo progressive shortening at the ends of their chromosomes, at regions called telomeres. A new system developed in the lab allows modulated expression of telomerase inside cells. This expression system has been used to perform critical tests of current models for cell aging and cell death.

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                                              Journal Publications and Graduate Student Thesises