James S. Godde
Dr. Godde received his Ph.D. in biochemistry from the University of Illinois, Urbana-Champaign, in 1993. He then spent four years doing postdoctoral research in the area of molecular biology at the National Institutes of Health as well as an equivalent amount of time teaching biology at CUNY Brooklyn College. Since 2001, Dr. Godde has been a member of the faculty at Monmouth College where he currently holds the position of professor and chair of the biology department.
Much progress has been made in recent years in the determination of the DNA sequence of a large variety of genomes, with over 1000 complete genomes published and nearly four times this amount ongoing. Precisely how this genetic information is expressed, however, remains poorly understood. While it is possible to perform top-down methods to measure the transcriptome and/or the proteome of a given cell type under a given set of conditions in a particular organism of interest, this is currently not feasible for all of the combinations which exist. A better understanding of gene expression would facilitate our being able to convert the fairly straight-forward information encoded in the sequence of nucleotide bases which make up a genome into the exceedingly more complex information that remains the ultimate goal of systems biology: monitoring the changes in the levels of every protein found in every cell throughout the lifetime of an organism. While much of the information which controls levels of gene expression is found in the non-protein coding regions of the genome and is therefore the subject of the genome projects in question, a considerable amount of gene expression, especially in eukaryotes, is controlled by reversible epigenetic changes to the DNA and its packaging, information which is not directly encoded by the DNA sequence. Epigenetic factors which control gene expression include DNA methylation, non-coding RNAs, chromatin remodeling, as well as changes in histone subtype and/or chemical modification.
My laboratory is interested in investigating the epigenetic control of eukaryotic gene expression. Our research involves the expression and purification of the components required to reconstitute long arrays of nucleosomes in vitro. These include both a DNA fragment which specifically positions long nucleosomal arrays as well as the recombinant proteins required for chromatin reconstitution. The proteins which we chromatographically purify include the four core histones (H2A, H2B, H3 & H4), various linker histones (including B4 and H1A), along with NAP-1, a histone chaperone whose presence is required for the correct assembly of linker histone-containing arrays of nucleosomes. Following the purification of the required components, we work to reconstitute long linker histone-containing arrays of nucleosomes, in vitro. This is a rather simple procedure involving salt dialysis but must be carefully monitored in order to ensure that the reconstituted chromatin mimics physiological conditions. Once these objectives are achieved, we then measure the relative sedimentation of reconstituted arrays under varying conditions of added linker histone and MgCl2 using ultracentrifugation techniques. This approach determines whether our reconstituted chromatin is in the extended form typically associated with transcriptionally active chromatin or in a more compact state, such as that which is typically associated with transcriptionally repressed chromatin. A final experimental approach is required to determine which parts of the linker histones in question are critical for changes in their chromatin compaction abilities by using chimeric histones containing various tripartite regions which have been swapped with other linker histones in the above reconstitution studies.
Courses Taught: Education:
Biol 200 Cell Biology
Biol 202 Genetics
Biol 354 Molecular Biology
Biol 302 Microbiology
Bioc 300 Bioinformatics
Intr 201 Global Perspectives: World Impact of East Asian Science
Intr 101 Introduction to the Liberal Arts
Biol 290 Wilderness
Post-doctoral National Institutes of Health 1997
Ph.D. University of Illinois, Urbana-Champaign 1993
B.S. Western Illinois University 1987
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