Professor, Microbiology & Molecular Genetics
|Chlamydia, bacterial pathogenesis, gene regulation, gene expression, transcription, host-pathogen interactions, protease, centrosome, cancer, infectious disease, sexually transmitted, infertility, trachoma, blindness|
|URLs||Department of Microbiology & Molecular Genetics webpage|
|Tan Lab webpage|
Clinical Investigator Award (K08), NIH
Established Investigator Grant, American Heart Association
Independent Scientist Award (K02), NIH
Fellow, Infectious Diseases Society of America
Dean’s Junior Physician/Scientist Award, College of Medicine, UC Irvine
Excellence in Teaching Award, School of Medicine, UC Irvine: 2004, 2008, 2009, 2010, 2012, 2013
|Appointments||To apply for a postdoctoral position in my research group, please email me, describing your research interests and goals and attaching your CV.|
Our research in the fields of bacterial pathogenesis and infectious diseases looks at how the intracellular bacterium Chlamydia causes disease. Chlamydial infections are the most commonly reported infectious disease in the country. Chlamydia trachomatis is the most common cause of bacterial sexually transmitted disease in the developed world, and a leading cause of preventable blindness in the developing world. In addition, genital strains of C. trachomatis have been associated with cervical cancer. A second species, Chlamydia pneumoniae, has been linked with atherosclerotic heart disease.
All chlamydial species share an unusual developmental life cycle that takes place within a eukaryotic host cell. We are studying a number of aspects of this intracellular infection:
1. Gene regulation: A central question is how this pathogen differentially regulates its genes during its developmental cycle and in response to environmental and metabolic cues. We are currently studying mechanisms of temporal regulation that control the expression of chlamydial genes at early, mid and late time points in the infectious cycle. These mechanisms include transcription factors, such as activators and repressors, alternative forms of RNA polymerase, and DNA supercoiling as a global regulator of gene expression. The approaches used include molecular biology, biochemistry and bioinformatics.
2. Host-pathogen interactions: Chlamydia manipulates and subverts numerous host processes in order to support its intracellular infection. We are studying how Chlamydia causes centrosome dysregulation such as the production of multiple centrosomes. These studies may provide a potential mechanism to explain the epidemiologic association of C. trachomatis and cervical cancer. We are also studying how Chlamydia effects on cilia may cause infertility in women. In a recent manuscript, we studied a chlamydial protease called CPAF that has been reported in many studies over 10 years to cleave or degrade multiple host proteins. However, we showed that this proteolysis was not detectable in intact infected cells and instead occured during experimental processing of the cells. These findings call into question the role of CPAF in a Chlamydia infection. These Chlamydia cell biology studies are a collaboration with Dr. Christine Suetterlin of the Department of Developmental and Cell Biology. Together, we are using a variety of cell biology approaches including immunofluorescent and electron microscopy, and protein analysis.
Niehus, E, Cheng, E. and Tan, M. DNA supercoiling–dependent gene regulation in Chlamydia. J. Bacteriol. 190: 6419-6427, 2008. (Selected for Faculty of 1000)
Park, N., Yamanaka, K., Tran, D., Chandrangsu, P., Akers, J.C., de Leon, J.C., Morrissette, N.S., Selsted, M.E. and Tan, M. The cell-penetrating peptide, Pep-1, has activity against intracellular chlamydial growth but not extracellular forms of Chlamydia trachomatis. J. Antimicrob. Chemother. 63:115-23, 2009.
Hasegawa, A., Sogo, L.F., Tan, M. and Sütterlin, C. The host complement regulatory protein, CD59, is transported to the chlamydial inclusion by a Golgi apparatus-independent pathway. Infect. Immun. 77:1285-1292, 2009. (Selected for Faculty of 1000)
Johnson, K., Tan, M. and Sütterlin, C. Centrosome abnormalities during a Chlamydia trachomatis infection are caused by dysregulation of the normal duplication pathway. Cell. Microbiol. 11:1064–1073, 2009.
Case, E.D., Peterson, E.M. and Tan, M. Promoters for Chlamydia Type III Secretion genes show a differential response to DNA supercoiling that correlates with temporal expression pattern. J. Bacteriol. 192:2569-2574, 2010.
Case, E.D., Akers, J.C. and Tan, M. CT406 encodes a chlamydial ortholog of NrdR, a repressor of ribonucleotide reductase. J. Bacteriol. 193:4396-4404, 2011.
Akers, J.C., HoDac, HM, Lathrop, R.H., and Tan, M. Identification and functional analysis of CT069 as a novel transcriptional regulator in Chlamydia. J. Bacteriol. 193: 6123-6131, 2011.
Chen, A.L., Wilson, A.C., and Tan, M. A Chlamydia-specific C-terminal region of the stress response regulator HrcA modulates its repressor activity. J. Bacteriol. 193: 6733-6741, 2011.
Cheng, E. and Tan, M. Differential effect of DNA supercoiling on Chlamydia early promoters correlates with expression pattern in midcycle. J. Bacteriol. 194: 3109-3115, 2012.
Rosario, C.J. and Tan, M. The early gene product EUO is a transcripitional repressor that selectively regulates promoters of Chlamydia late genes. Mol. Microbiol. 84:1097-1107, 2012.
Chen, A.L., Johnson, K.A., Lee, J.K., Sütterlin, C. and Tan, M. CPAF: A Chlamydial protease in search of an authentic substrate. PLoS Pathog. 8:e1002842, 2012. (Selected for Faculty of 1000)
Tan, M. and Bavoil, P.M. (ed.). Intracellular Pathogens I: Chlamydiales (Tan, M., Lead Editor) (ASM Press, Washington, DC), 2012.
Palmer, G.H. and Azad, A. (ed.). Intracellular Pathogens II: Rickettsiales (Tan, M., Lead Editor) (ASM Press, Washington, DC), 2012.
Tan, M. and Bavoil, P.M. Introduction: Current and Future Aspects of Chlamydia Research. In Intracellular Pathogens I: Chlamydia. M. Tan and P.M. Bavoil, ed., (ASM Press, Washington, DC), 2012.
Tan, M. Temporal gene regulation during the chlamydial development cycle. In Intracellular Pathogens I: Chlamydiales. M. Tan and P.M. Bavoil, ed., (ASM Press, Washington, DC), 2012.
American Society for Microbiology: Division D (Bacteria of Medical Importance) Chair (2005-6), Division Advisor (2006-7)
Chlamydia Basic Research Society: Secretary-Treasurer (2007-11), President-Elect (2011-2013), President (2013-2015)
Infectious Diseases Society of America: Fellow
Cellular and Molecular Biosciences
Infectious Disease (IM)
|Research Center||UC Irvine Chao Family Comprehensive Cancer Center|
|Link to this profile||http://www.faculty.uci.edu/profile.cfm?faculty_id=4507|