Publications de Jeffrey Chen | EPFL Graph Search

The cysteine desulfurase IscS of Mycobacterium tuberculosis is involved in iron sulfur cluster biogenesis and oxidative stress defence

Stewart Cole, Florence Pojer, Gaëlle Séraphine Kolly, Jan Lars Rybniker, Jeffrey Chen

The complex multiprotein systems for the assembly of protein-bound iron sulfur (Fe S) clusters are well defined in Gram-negative model organisms. However, little is known about Fe S cluster biogenesis in other bacterial species. The ISC (iron sulfur cluste ...

Portland Press2014

Anticytolytic Screen Identifies Inhibitors of Mycobacterial Virulence Protein Secretion

Stewart Cole, Claudia Sala, Ruben Hartkoorn, Andrej Benjak, Ming Zhang, Anthony Vocat, Jan Lars Rybniker, Jeffrey Chen, Edina Rita Székely

Mycobacterium tuberculosis (Mtb) requires protein secretion systems like ESX-1 for intracellular survival and virulence. The major virulence determinant and ESX-1 substrate, EsxA, arrests phagosome maturation and lyses cell membranes, resulting in tissue d ...

Cell Press2014

EspI regulates the ESX-1 secretion system in response to ATP levels in Mycobacterium tuberculosis

Stewart Cole, Neeraj Dhar, Claudia Sala, Ming Zhang, Jan Lars Rybniker, Jeffrey Chen

The function of EspI, a 70kDa protein in Mycobacterium tuberculosis, has remained unclear. Although EspI is encoded by a gene within the esx-1 locus, in this study we clarify previous conflicting results and show that EspI is not essential for ESX-1-mediat ...

Wiley-Blackwell2014

Mycobacterium tuberculosis EspB binds phospholipids and mediates EsxA-independent virulence

Stewart Cole, Neeraj Dhar, Florence Pojer, Ming Zhang, Stefanie Boy-Röttger, Jan Lars Rybniker, Jeffrey Chen

The type-VII ESX-1 secretion apparatus, encoded by the esx-1 genetic locus, is essential for the export of EsxA and EsxB, two major virulence factors of Mycobacterium tuberculosis. ESX-1 also requires the products of the unlinked espACD operon for optimal ...

Wiley-Blackwell2013

Phenotypic Profiling of Mycobacterium tuberculosis EspA Point Mutants Reveals that Blockage of ESAT-6 and CFP-10 Secretion In Vitro Does Not Always Correlate with Attenuation of Virulence

Stewart Cole, Neeraj Dhar, Florence Pojer, Ming Zhang, Jan Lars Rybniker, Jeffrey Chen, Anna De Graff Tischler

The EspA protein of Mycobacterium tuberculosis is essential for the type VII ESX-1 protein secretion apparatus, which delivers the principal virulence factors ESAT-6 and CFP-10. In this study, site-directed mutagenesis of EspA was performed to elucidate it ...

American Society for Microbiology2013

Virulence Regulator EspR of Mycobacterium tuberculosis Is a Nucleoid-Associated Protein

Stewart Cole, Florence Pojer, Jacques Rougemont, Claudia Sala, Ruben Hartkoorn, Swapna Uplekar, Benjamin Blasco, Jeffrey Chen

The principal virulence determinant of Mycobacterium tuberculosis (Mtb), the ESX-1 protein secretion system, is positively controlled at the transcriptional level by EspR. Depletion of EspR reportedly affects a small number of genes, both positively or neg ...

Public Library of Science2012

A Point Mutation in cycA Partially Contributes to the D-cycloserine Resistance Trait of Mycobacterium bovis BCG Vaccine Strains

Stewart Cole, Swapna Uplekar, Jeffrey Chen

In mycobacteria, CycA a D-serine, L-and D-alanine, and glycine transporter also functions in the uptake of D-cycloserine, an important second-line anti-tubercular drug. A single nucleotide polymorphism identified in the cycA gene of BCG was hypothesized to ...

Public Library of Science2012

ESAT-6 secretion-independent impact of ESX-1 genes espF and espG1 on virulence of Mycobacterium tuberculosis

Stewart Cole, Jeffrey Chen

The pathogenesis of Mycobacterium tuberculosis largely depends on the secretion of the 6-kD early secreted antigenic target ESAT-6 (EsxA) and the 10-kD culture filtrate protein CFP-10 (EsxB) via the ESX-1/typeVII secretion system. Although gene products fr ...

Oxford University Press2011

EspD Is Critical for the Virulence-Mediating ESX-1 Secretion System in Mycobacterium tuberculosis

Stewart Cole, Neeraj Dhar, Florence Pojer, Stefanie Boy-Röttger, Jeffrey Chen

ESAT-6 system 1 (ESX-1)-mediated secretion in Mycobacterium tuberculosis is dependent on proteins encoded by the cotranscribed espA-espC-espD gene cluster. While the roles of EspA and EspC with respect to the ESX-1 secretion system have been actively inves ...

American Society for Microbiology2011

Sigma Factor F does not Prevent Rifampin Inhibition of RNA Polymerase or Cause Rifampin Tolerance in Mycobacterium tuberculosis

Stewart Cole, Florence Pojer, Claudia Sala, Ruben Hartkoorn, Sophie Magnet, Jeffrey Chen

The tolerance of Mycobacterium tuberculosis to anti-tuberculosis drugs is a major reason for the lengthy therapy needed to treat a tuberculosis infection. Rifampin is a potent inhibitor of RNA polymerase (RNAP) in vivo, but has been shown to be less effect ...

American Society for Microbiology2010