Title(s): Research Associate Professor of Microbiology and Immunology
Department(s): Microbiology and Immunology
Education: Rutgers - The State University, Ph.D ., 1988 University of New Haven, B.S., 1982 University of New Haven, A.S., 1980
After postdoctoral work at the DuPont Merck Pharmaceutical Company and in the Department of Microbiology at Dartmouth Medical School, Dr. Skorupski joined the faculty of the Department of Microbiology at Dartmouth Medical School in 1997.
Lin W, Kovacikova G, Skorupski K The quorum sensing regulator HapR downregulates the expression of the virulence gene transcription factor AphA in Vibrio cholerae by antagonizing Lrp- and VpsR-mediated activation. Mol Microbiol 2007 May; 64(4):953-67 PMID: 17501920 [PubMed - indexed for MEDLINE]
Kovacikova G, Lin W, Skorupski K Dual regulation of genes involved in acetoin biosynthesis and motility/biofilm formation by the virulence activator AphA and the acetate-responsive LysR-type regulator AlsR in Vibrio cholerae. Mol Microbiol 2005 Jul; 57(2):420-33 PMID: 15978075 [PubMed - indexed for MEDLINE]
Lin W, Kovacikova G, Skorupski K Requirements for Vibrio cholerae HapR binding and transcriptional repression at the hapR promoter are distinct from those at the aphA promoter. J Bacteriol 2005 May; 187(9):3013-9 PMID: 15838027 [PubMed - indexed for MEDLINE]
De Silva RS, Kovacikova G, Lin W, Taylor RK, Skorupski K, Kull FJ Crystal structure of the virulence gene activator AphA from Vibrio cholerae reveals it is a novel member of the winged helix transcription factor superfamily. J Biol Chem 2005 Apr 8; 280(14):13779-83 PMID: 15647287 [PubMed - indexed for MEDLINE]
Kovacikova G, Lin W, Skorupski K Vibrio cholerae AphA uses a novel mechanism for virulence gene activation that involves interaction with the LysR-type regulator AphB at the tcpPH promoter. Mol Microbiol 2004 Jul; 53(1):129-42 PMID: 15225309 [PubMed - indexed for MEDLINE]
Kovacikova G, Lin W, Skorupski K The virulence activator AphA links quorum sensing to pathogenesis and physiology in Vibrio cholerae by repressing the expression of a penicillin amidase gene on the small chromosome. J Bacteriol 2003 Aug; 185(16):4825-36 PMID: 12897002 [PubMed - indexed for MEDLINE]
Kovacikova G, Skorupski K Regulation of virulence gene expression in Vibrio cholerae by quorum sensing: HapR functions at the aphA promoter. Mol Microbiol 2002 Nov; 46(4):1135-47 PMID: 12421317 [PubMed - indexed for MEDLINE]
Professional Interests:
Vibrio cholerae is the causative agent of the severe diarrheal disease cholera. We are interested in the regulation of virulence gene expression during V. cholerae infection. Toxigenic strains of V. cholerae possess two distinct phage derived pathogenicity islands, VPI which encodes the toxin-coregulated pilus (TCP), an essential colonization factor, and CTX which encodes cholera toxin (CT). We have recently identified two new transcriptional regulators, AphA and AphB, which function synergistically to activate the expression of TCP and CT by activating the expression of a membrane bound transcriptional activator, TcpP, which is encoded on the VPI. AphA appears to be a novel type of transcriptional activator with no known homologs and AphB is a member of the LysR family. The activation of TcpP by AphA and AphB occurs only under certain environmental conditions and appears to be the initial regulatory step in the virulence transcriptional cascade. Mutants defective for either one of these genes are attenuated in the infant mouse cholera model. Interestingly, AphA and AphB are not themselves encoded on the VPI or CTX elements but are located in regions of the V. cholerae chromosome not previously associated with pathogenesis. Thus, these proteins are likely to play a role in normal cellular physiology and function to couple physiological responses with virulence gene expression. We are utilizing a combination of genetic and biochemical approaches to elucidate the mechanism of AphA and AphB mediated transcriptional activation of tcpP and to understand how these two proteins couple environmental conditions to the expression of virulence genes. Since LysR regulators are known to require small molecule coinducers present under certain conditions to activate gene expression, it is hoped that these studies will lead to the identification of new targets for antimicrobial design.