Steven W. Hutcheson
Ph.D. - University of California, Berkeley, 1982
Professor
Department
of Cell Biology and Molecular Genetics
University of Maryland
College Park, MD 20742
Telephone: (301)-405-5498
Fax: (301)-314-9082
E-mail: sh53@umail.umd.edu
Research Interests: Prokaryotic Molecular Biology; Plant Pathology
The pathogenicity and host range of the gram negative bacterium, Pseudomonas syringae, is linked to a set of genes presently known as hrp genes. At least 25 hrp genes have been identified, sequenced and shown to be organized into multiple transcriptional units within a 25 kb gene cluster. This gene cluster has recently been shown by my group and others to encode an apparently dedicated regulatory system, a type III protein secretion apparatus and a secreted protein product which is responsible in part for the overall pathogenic phenotype of the bacterium.
We are presently characterizing a multi-component regulatory cascade which controls the environmental regulation of these genes. The regulatory system involves the smallest known sigma factor and two unusual regulatory proteins. A second facet of my current research program uses the hrp gene cluster as a means to elucidate the mechanism of type III protein secretion. Type III protein secretion is the most recently discovered mechanism by which bacteria secrete proteins and is best known for its role in the secretion of virulence factors by enteric bacteria pathogenic to mammals. This mechanism is distinct from classic signal sequence-dependent mechanisms or single step secretion systems. A third facet of my research is attempting to understand the mechanisms by which the secreted proteins control the pathogenicity and host range of the bacterium. This work involves gene substitution fusions, manipulation of gene expression and searches for ancillary genes affecting host range.
Skills students can learn in my laboratory include molecular genetics, gene cloning and characterization, PCR, DNA sequencing, protein purification and characterization, DNA-protein interactions, construction and use of reporter gene fusions, engineered expression of proteins, and a variety of immunological analyses.
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