A multitude of macromolecular protein interactions must properly occur on chromatin to drive functional aspects of chromosome biology like gene transcription, DNA replication, recombination, repair and sister chromatid segregation. Analyzing how proteins interact in vivo with chromatin to direct these activities remains a significant challenge due to the temporal and dynamic nature of their associations. We have recently developed a technique termed Chromatin Affinity Purification with Mass Spectrometry (ChAP-MS) that provides for the enrichment of a native 1 kb section of a chromosome for site-specific identification of protein interactions and associated histone posttranslational modifications (PTMs). In this grant application, we plan to use this cutting-edge approach to define the histone PTMs and proteins regulating transcription at the arsenic response locus in budding yeast. We hypothesize that ChAP-MS will provide for a comprehensive and unbiased identification of all histone modifications and proteins regulating transcription at the arsenic locus in S. cerevisiae. We will pursue the following Aim to test this hypothesis: Use ChAP-MS to define the histone PTMs and proteins regulating transcription at the arsenic response locus in S. cerevisiae.

Public Health Relevance

Arsenic is a nonmutagenic carcinogen that promotes cancer via unknown mechanisms. Millions of people worldwide have been exposed to toxic levels of arsenic through water and food consumption. When an organism is exposed to arsenic, it responds by producing proteins to detoxify the heavy metal. Production of these proteins is regulated by epigenetics or regulatory factors beyond the DNA sequence. The mechanism of epigenetic regulation in response to arsenic exposure is not understood, thus uncovering the molecular components regulating the arsenic epigenetic response will provide novel targets for maximizing treatment. In this proposal, we will use cutting-edge technologies to identify these epigenetic components regulating arsenic detoxification and provide a more complete mechanistic understanding of cellular response to arsenic exposure.

National Institute of Health (NIH)
National Institute of Environmental Health Sciences (NIEHS)
Exploratory/Developmental Grants (R21)
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Special Emphasis Panel (ZRG1-DKUS-C (90))
Program Officer
Tyson, Frederick L
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University of Arkansas for Medical Sciences
Schools of Medicine
Little Rock
United States
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