Meet the researchers at BPAST

  • Kenney lab

Principal investigator

Linda J Kenney kenneyl@uic.edu

Researchers

 

chakraborty

Smarajit Chakraborty

mbisc@nus.edu.sg

I am interested in understanding the intricate process of signal transduction and elucidating virulence determinants in pathogenic bacteria. I am particularly interested in understanding the role of regulatory genes at the cellular and mechanistic level. I completed my Bachelor's degree in Microbiology and my Master's degree in Biodiversity from the University of Pune, India. This platform helped me to understand the pathogenic and evolutionary potential of micro-organisms. My doctoral research in Henry Mok's lab in the Dept. of Biological Sciences, NUS was based on characterizing two component systems (2CS) in the fish pathogen Edwardsiella tarda. I used molecular biology, biophysical and proteomics approaches to identify the novel role of PhoP/PhoQ as a temperature sensor and identified a cross talk between phosphate (PhoB/PhoR) and iron (Fur) mediated regulation. As a postdoctoral fellow in Linda Kenney's lab at the Mechanobiology Institute, NUS, I have continued exploring the regulation of pathogenic bacteria, namely Salmonella and Escherichia coli in response to diverse environmental cues. I am using a newly devised DNA Nanosensor known as the ‘I-switch' to monitor changes in bacterial intracellular pH under osmotic stress, acid stress and during infection in mammalian cells. I am also screening a library of small molecules to understand the signal transduction pathways of Salmonella pathogenesis to design better inhibitors for therapeutic purposes.

Chakraborty S, Mizusaki H, Kenney LJ. A FRET-based DNA biosensor tracks OmpR-dependent acidification of Salmonella during macrophage infection. PLOS Biology. April 2015. 13(4):e1002116.

Chakraborty S, Li M, Chatterjee C, Sivaraman J, Leung KY, Mok YK (2010) Temperature and Mg2+ Sensing by a Novel PhoP-PhoQ Two-component System for Regulation of Virulence in Edwardsiella tarda. J Biol Chem 285: 38876-38888.

Chakraborty S, Sivaraman J, Leung KY, Mok YK (2011): Two-component PhoB-PhoR Regulatory System and Ferric Uptake Regulator Sense Phosphate and Iron to Control Virulence Genes. J Biol Chem  286. 39417-39430.

Jobichen C, Chakraborty S, Li M, Zheng J, Joseph L, Mok YK, Leung KY, Sivaraman J (2010) Structural basis for the secretion of EvpC: a key type VI secretion system protein from Edwardsiella tarda. PLoS One 5: e12910.

Chatterjee C, Kumar S, Chakraborty S, Yih Wan Tan Y W, Leung K Y, Sivaraman J, and Mok Y K (2011) Crystal structure of the heteromolecular chaperone, AscE-AscG, from the type III secretion system in Aeromonas hydrophila. PLOS one 6: e19208


stuti desai

Stuti Desai

mbidsk@nus.edu.sg

I joined the Kenney group in May, 2012 with a strong urge to amalgamate my doctoral training in studying silent genetic systems in enterics to decipher the behavior of bacteria under various environmental challenges. I obtained my doctorate from the Indian Institute of Science, Bangalore, India, under the guidance of Prof Subramony Mahadevan. I studied Biochemistry for my Master's degree and Chemistry, Physics and Zoology for my Bachelor's degree at the Maharaja Sayajirao University of Baroda, Baroda, India.

Desai, S. K., Nandimath, K., Mahadevan, S., (2010) Diverse pathways for salicin utilization in Shigella sonnei and Escherichia coli carrying an impaired bgl operon. Arch Microbiol 192: 821-3.

Desai, S. K. and Mahadevan S., (2006) Accumulation of hns mutations specifically in stationary phase in an E. coli strain carrying an impaired rpoS locus. J Genet 85: 221-4.


yong hwee foo

Yong Hwee Foo

mbifyh@nus.edu.sg

I did my B.Sc. in the department of chemistry at the National University of Singapore (NUS), majoring in analytic chemistry. I was then employed by Singapore Eye Research Institute and worked in the area of biomarker discovery related to eye diseases using nano-spray liquid chromatography-tandem mass spectrometry. I was also involved in the synthesis of antimicrobial peptides using solid phase peptide synthesis. Two years later, I went on to pursue a Ph.D. in the field of fluorescence biophysics under Thorsten Wohland in NUS and Sohail Ahmed from the Institute of Medical Biology (A*Star) where I focused on using fluorescence cross-correlation spectroscopy (FCCS) to probe biomolecular interaction in living cells. I also had the opportunity to spend three months in the European Molecular Biology Laboratory (EMBL) in Heidelberg as a short-term follow. After obtaining my Ph.D., I joined the Mechanobiology Institute in the lab of Linda J. Kenney as a research fellow working on understanding bacteria signaling by applying fluorescence methods.


yunfeng gao

Yunfeng Gao

mbigy@nus.edu.sg

I was trained as a molecular biologist in the Department of Biological Sciences, National University of Singapore.  My project was a collaboration with the Department of Otolaryngology, focusing on characterization of novel allergens from house dust mites. During the study, I noticed that the local sequence and structure of a protein are so important that only a few amino acids changes in an allergen will induce severe allergic responses in patients. After receiving my PhD degree, I joined Dr. Ganesh Anand's lab in the Department of Biological Sciences, NUS, to study the effect of protein structure  and dynamics on its function. Currently, I am working with Prof. Linda Kenney in the Mechanobiology Institute and collaborating with Dr. Ganesh Anand to investigate the mechanism of EnvZ/OmpR mediated osmoregulation of ompC and ompF in E.coli.


hideaki mizusaki

Hideaki Mizusaki

mbihm@nus.edu.sg

I am interested in the mechanism of assembly of the SPI-2 needle structure of Salmonella. During my Ph.D. in Dr. Shin-Ichi Aizawa's lab at Prefectural University of Hiroshima, I studied the Salmonella pathogenicity island 1 (SPI-1) regulation by using a combination of microscopic, biophysical and molecular biology techniques. I joined Linda Kenney's lab at the University of Illinois at Chicago, as a post-doctoral fellow and continued studying regulation, assembly and needle structure of the SPI-2 secretion system in Salmonella. Currently, I am working in the Mechanobiology Institute (MBI) at NUS trying to optimize the environmental triggers to maximize SPI-2 expression and visualize SPI-2 needle structure assembly.

Mizusaki, H., Takaya, A., Yamamoto, T., Aizawa, S. 2008.
Signal pathway in salt-activated expression of the Salmonella pathogenicity island 1 type III secretion system in Salmonella enterica serovar Typhimurium. J. Bacteriol. 2008 190: 4624-4631


soyuma ranganathan

Souyma Ranganathan

mbisora@nus.edu.sg

I completed my Bachelors degree in Industrial biotechnology from Anna University, Chennai (India) in June, 2009. I then decided to pursue my graduate studies in the Department of Biological Sciences, NUS where I worked on the structural and functional characterisation of proteins using various biophysical techniques and X-ray crystallography and graduated with a Master's degree in June, 2012. The manuscripts of my research work are in preparation. I am currently employed as a research assistant in the Mechanobiology Institute (MBI), Singapore where I am working on a collaborative project under Prof. Linda Kenney (MBI) and Asst. Prof. Ganesh Anand (DBS).  The current work deals with probing the mechanisms of sensing by membrane histidine kinases using hydrogen-deuterium exchange mass spectrometry and X-ray crystallography.


roopa rajashekar

Roopa Rajashekar

mbirr@nus.edu.sg

I was always interested in infection biology. The manner in which pathogens manipulate host systems and causes fatal diseases intrigued me a lot. Therefore after my pre-university, I did my Bachelor's degree (Bangalore University) with Microbiology as one of the majors. Later I went on to do my Masters degree also in Biotechnology (Bangalore University) where we were introduced to Molecular biology and Cell biology. This interested me a lot and after briefly working as research assistant at the Indian Institute of Science in Bangalore, where my research was on tuberculosis and human immunity, I headed to Germany (Friedrich Alexander University, Erlangen-Nurenberg) to do my PhD, also on host-pathogen interaction; the model pathogen was Salmonella. I hope to continue my curiosity-driven research in this field and contribute to the scientific understanding of the interplay between the host and pathogen in a small way.


mrinal shah

Mrinal Shah

shah.mrinal@gmail.com

I was introduced to the complex world of microbiology during my bachelors degree from the University of Pune, followed by a master's degree in microbiology from The M.S. University of Baroda, India. I was introduced to the various genetic processes and gene regulation in microorganisms. While reading about the research done in this area, I was amazed by the extraordinarily complex and diverse processes of gene regulation for development and differentiation and how bacteria have been evolving as a pathogen with a continuous interaction with the hosts. With this interest in mind, I joined as a graduate student in Prof. Linda Kenney's lab in August 2012. I am working on host pathogen interactions. Different pathogens have evolved various strategies, depending on their niche and site of infection. For example, Enteropathogenic E. coli as an extracellular pathogen, has evolved strategies such that it can remain outside the host cell and still relay information to the nucleus. One of the ways it does this is to stimulate actin polymerization under the membrane, leading to the formation of pedestal-like structures. Salmonella, on the other hand is an intracellular pathogen and it infects the host cell by surviving the vacuolar environment and forming ‘Salmonella-containing vacuoles'.  Thus, the cytoplasmic signals through which a pathogen translates information to the nucleus are very important from both the host and the pathogen perspective.  It is this constant battle between the host and a pathogen to succeed and sustain is what interests me.


hong fang zhang

Hong Fang Zhang

mbizh@nus.edu.sg

I obtained my B.S. in Bioengineering from Tianjin University, China in 2006. After my graduation, I was accepted as a Ph.D candidate by Nanyang Technological University, Singapore, majoring in Chemical and Biomedical Engineering. During this time, I worked on improving cell phenotypes in biofuel production by rewiring the global transcription factor cAMP receptor protein (CRP). To further my understanding of transcriptional regulation and signal transduction, I joined the Bacterial Pathogenesis & Signal Transduction Lab to work on the OmpR/EnvZ two component regulatory system in 2011 after my PhD.

Chong H. Q., Huang L., Yeow J. W., Wang I., Zhang H. F., Song H., Jiang R. R. (2013). “Improving ethanol tolerance of Escherichia coli by rewiring its global regulator cAMP receptor protein (CRP).” PLOS ONE (accepted)

Zhang H. F., Chong H. Q., Ching C. B., Song H. and Jiang R. R. (2012). "Engineering global transcription factor cyclic AMP receptor protein of Escherichia coli for improved 1-butanol tolerance." Applied Microbiology and Biotechnology 94(4): 1107-1117.

Zhang H. F., Chong H. Q., Ching C. B. and Jiang R. R. (2012). "Random mutagenesis of global transcription factor cAMP receptor protein for improved osmotolerance." Biotechnology and Bioengineering 109(5): 1165-1172.

Wang L., Zhang H. F., Ching C. B., Chen Y. and Jiang R. R. (2012). "Nanotube-supported bioproduction of 4-hydroxy-2-butanone via in situ cofactor regeneration." Applied Microbiology and Biotechnology 94(5): 1233-1241.

Zhang H. F., Lountos G. T., Ching C. B. and Jiang R. R. (2010). "Engineering of glycerol dehydrogenase for improved activity towards 1, 3-butanediol." Applied Microbiology and Biotechnology 88(1): 117-124.


Collaborators

Jeremy Wang | wangloochien@nus.edu.sg

Ci Ji LIM |

Alumni

Hong Fang Zhangmbizh@nus.edu.sg