Associate Professor - Veterinary and Biomedical Sciences

e-mail: jixxx002@umn.edu

Research Interests
Dr. Ji's laboratory performs studies involving the functional genomics and molecular pathogenesis of a serious human and animal pathogen, Staphylococcus aureus.  Specifically, we focus on different two-component signal transduction regulatory systems and several functional unknown essential proteins.  We have developed a powerful regulated antisense RNA technology which allows titration of any gene product both in bacterial cell culture and during infection.  Current efforts include determination of function of critical unknown genes and regulons for bacterial growth and/or pathogenesis, and identification of host cell signaling pathways associated with pathogenicity during host-pathogen interaction and apoptosis.  These efforts not only will provide new insight into molecular mechanism of pathogenesis but also may deliver unexploited targets for developing preventive and/or therapeutic agents against this life-threatening pathogen and benefit public health.  Molecular genetic, antisense RNA, microarray, genomics, proteomics, cell culture, immunochemical, and sophisticated imaging methods are used in these studies.

Selected Publications
(For a comprehensive list of  Dr. Ji's recent publications, refer to PubMed, a service provided by the National Library of Medicine.)

Liang, X., Ji, Y. 2007. Involvement of alpha5beta1-integrin and TNF-alpha in Staphylococcus aureus alpha-toxin-induced death of epithelial cells. Cellular Microbiology 9: 1809-1821.

Zheng, L., Yu, C., Bayles, K., Lasa, I., Ji, Y. 2007. Conditional mutation of an essential putative glycoprotease eliminates autolysis in Staphylococcus aureus. Journal of Bacteriology 189: 2734-2742.

Ji, Y., Yu, C., Liang, X. 2007.  Trancriptomic analysis of ArlSR two-component signaling operon in Staphylococcus aureus. Methods in Enzymology 423: 502-513.

Liang, X., Ji, Y. 2006. Alpha-toxin interferes with integrin-mediated adhesion and internalization of Staphylococcus aureus by human lung epithelial cells. Cellular Microbiology 8: 1656-1668.

Liang, X., Yu, C., Sun, J., Liu, H., Landwehr, C., Holmes, D., Ji, Y. 2006. Inactivation of a two-component signal transduction system, SaeRS, eliminates adhesion and attenuates virulence of Staphylococcus aureus.  Infection and Immunity 74: 4655-4665.

Sun, J., Zheng, L., Landwehr, C., Yang, J., Ji, Y. 2005. Identification of a novel essential two-component signal transduction system, YhcSR, in Staphylococcus aureus. Journal of Bacteriology 187: 7886-7880.

Zheng, L., Yang, J., Landwehr, C., Fan, F., Ji, Y. 2005. Identification of an essential glycoprotease in Staphylococcus aureus. FEMS Microbiology Letters 245: 279-285.

Liang, X., Zheng, L., Landwehr, C., Lunsford,  D., Holmes, D., Ji, Y. 2005. Global regulation of gene expression by ArlRS, a two-component signal transduction regulatory system of Staphylococcus aureus. Journal of Bacteriology 187: 5486-5492.

Yin, D., Fox, B., Lonetto, M., Etherton, M., Payne, D., Holmes, D., Rosenberg, M., Ji, Y. 2004. Identification of antimicrobial targets using a comprehensive genomic approach. Pharmacogenomics 5: 101-113.

Yin, D., Ji, Y. 2002. Genomic analysis using conditional phenotypes generated by antisense RNA. Current Opinion in Microbiology 5: 330–333.

Ji, Y., Zhang, B., Van Horn, S., Warren, P., Burnham, M., Woodnutt, G., Rosenberg, M. 2001. Identification of critical staphylococcal genes using conditional growth phenotypes generated by antisense RNA. Science 293: 2266-2269.

Current Funding
“Novel antibacterial target: An Essential Glycoprotease,” NIH, PI

"A Novel Essential Regulator of Staphylococcus aureus,” NIH, PI

"Identification of Novel Key Genes for S. aureus Infections," AHC, PI