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Articles 1 - 6 of 6

Full-Text Articles in Molecular Biology

Role Of Granulocyte-Macrophage Colony-Stimulating Factor Production By T Cells During Mycobacterium Tuberculosis Infection, Alissa C. Rothchild, Britni L. Stowell, Girija Goyal, Claudio Nunes-Alves, Qianting Yang, Kadamba Papavinasasundaram, Christopher M. Sassetti, Glenn Dranoff, Xinchun Chen, Jinhee Lee, Samuel M. Behar Oct 2017

Role Of Granulocyte-Macrophage Colony-Stimulating Factor Production By T Cells During Mycobacterium Tuberculosis Infection, Alissa C. Rothchild, Britni L. Stowell, Girija Goyal, Claudio Nunes-Alves, Qianting Yang, Kadamba Papavinasasundaram, Christopher M. Sassetti, Glenn Dranoff, Xinchun Chen, Jinhee Lee, Samuel M. Behar

UMass Metabolic Network Publications

Mice deficient for granulocyte-macrophage colony-stimulating factor (GM-CSF(-/-)) are highly susceptible to infection with Mycobacterium tuberculosis, and clinical data have shown that anti-GM-CSF neutralizing antibodies can lead to increased susceptibility to tuberculosis in otherwise healthy people. GM-CSF activates human and murine macrophages to inhibit intracellular M. tuberculosis growth. We have previously shown that GM-CSF produced by iNKT cells inhibits growth of M. tuberculosis However, the more general role of T cell-derived GM-CSF during infection has not been defined and how GM-CSF activates macrophages to inhibit bacterial growth is unknown. Here we demonstrate that, in addition to nonconventional T cells, conventional T ...


Statistical Analysis Of Genetic Interactions In Tn-Seq Data, Michael A. Dejesus, Subhalaxmi Nambi, Clare M. Smith, Richard E. Baker, Christopher M. Sassetti, Thomas R. Ioerger Feb 2017

Statistical Analysis Of Genetic Interactions In Tn-Seq Data, Michael A. Dejesus, Subhalaxmi Nambi, Clare M. Smith, Richard E. Baker, Christopher M. Sassetti, Thomas R. Ioerger

UMass Metabolic Network Publications

Tn-Seq is an experimental method for probing the functions of genes through construction of complex random transposon insertion libraries and quantification of each mutant's abundance using next-generation sequencing. An important emerging application of Tn-Seq is for identifying genetic interactions, which involves comparing Tn mutant libraries generated in different genetic backgrounds (e.g. wild-type strain versus knockout strain). Several analytical methods have been proposed for analyzing Tn-Seq data to identify genetic interactions, including estimating relative fitness ratios and fitting a generalized linear model. However, these have limitations which necessitate an improved approach. We present a hierarchical Bayesian method for identifying ...


Comprehensive Essentiality Analysis Of The Mycobacterium Tuberculosis Genome Via Saturating Transposon Mutagenesis, Michael A. Dejesus, Elias R. Gerrick, Weizhen Xu, Sae Woong. Park, Jarukit E. Long, Cara C. Boutte, Eric J. Rubin, Dirk Schnappinger, Sabine Ehrt, Sarah M. Fortune, Christopher M. Sassetti, Thomas R. Ioerger Jan 2017

Comprehensive Essentiality Analysis Of The Mycobacterium Tuberculosis Genome Via Saturating Transposon Mutagenesis, Michael A. Dejesus, Elias R. Gerrick, Weizhen Xu, Sae Woong. Park, Jarukit E. Long, Cara C. Boutte, Eric J. Rubin, Dirk Schnappinger, Sabine Ehrt, Sarah M. Fortune, Christopher M. Sassetti, Thomas R. Ioerger

UMass Metabolic Network Publications

For decades, identifying the regions of a bacterial chromosome that are necessary for viability has relied on mapping integration sites in libraries of random transposon mutants to find loci that are unable to sustain insertion. To date, these studies have analyzed subsaturated libraries, necessitating the application of statistical methods to estimate the likelihood that a gap in transposon coverage is the result of biological selection and not the stochasticity of insertion. As a result, the essentiality of many genomic features, particularly small ones, could not be reliably assessed. We sought to overcome this limitation by creating a completely saturated transposon ...


Structural And Genetic Analyses Of The Mycobacterium Tuberculosis Protein Kinase B Sensor Domain Identify A Potential Ligand-Binding Site, Daniil M. Prigozhin, Kadamba Papavinasasundaram, Christina E. Baer, Kenan C. Murphy, Alisa Moskaleva, Tony Y. Chen, Tom Alber, Christopher M. Sassetti Oct 2016

Structural And Genetic Analyses Of The Mycobacterium Tuberculosis Protein Kinase B Sensor Domain Identify A Potential Ligand-Binding Site, Daniil M. Prigozhin, Kadamba Papavinasasundaram, Christina E. Baer, Kenan C. Murphy, Alisa Moskaleva, Tony Y. Chen, Tom Alber, Christopher M. Sassetti

UMass Metabolic Network Publications

Monitoring the environment with serine/threonine protein kinases is critical for growth and survival of Mycobacterium tuberculosis, a devastating human pathogen. Protein kinase B (PknB) is a transmembrane serine/threonine protein kinase that acts as an essential regulator of mycobacterial growth and division. The PknB extracellular domain (ECD) consists of four repeats homologous to penicillin-binding protein and serine/threonine kinase associated (PASTA) domains, and binds fragments of peptidoglycan. These properties suggest that PknB activity is modulated by ECD binding to peptidoglycan substructures, however, the molecular mechanisms underpinning PknB regulation remain unclear. In this study, we report structural and genetic characterization ...


Fine-Tuning Of Substrate Affinity Leads To Alternative Roles Of Mycobacterium Tuberculosis Fe2+-Atpases, Sarju J. Patel, Brianne E. Lewis, Jarukit E. Long, Subhalaxmi Nambi, Christopher M. Sassetti, Timothy L. Stemmler, Jose M. Arguello May 2016

Fine-Tuning Of Substrate Affinity Leads To Alternative Roles Of Mycobacterium Tuberculosis Fe2+-Atpases, Sarju J. Patel, Brianne E. Lewis, Jarukit E. Long, Subhalaxmi Nambi, Christopher M. Sassetti, Timothy L. Stemmler, Jose M. Arguello

UMass Metabolic Network Publications

Little is known about iron efflux transporters within bacterial systems. Recently, the participation of Bacillus subtilis PfeT, a P1B4-ATPase, in cytoplasmic Fe(2+) efflux has been proposed. We report here the distinct roles of mycobacterial P1B4-ATPases in the homeostasis of Co(2+) and Fe(2+) Mutation of Mycobacterium smegmatis ctpJ affects the homeostasis of both ions. Alternatively, an M. tuberculosis ctpJ mutant is more sensitive to Co(2+) than Fe(2+), whereas mutation of the homologous M. tuberculosis ctpD leads to Fe(2+) sensitivity but no alterations in Co(2+) homeostasis. In vitro, the three enzymes are activated by both ...


Spatially Distinct And Metabolically Active Membrane Domain In Mycobacteria, Jennifer M. Hayashi, John D. Leszyk, Christina E. Baer, Scott A. Shaffer, Christopher M. Sassetti, Yasu S. Morita May 2016

Spatially Distinct And Metabolically Active Membrane Domain In Mycobacteria, Jennifer M. Hayashi, John D. Leszyk, Christina E. Baer, Scott A. Shaffer, Christopher M. Sassetti, Yasu S. Morita

UMass Metabolic Network Publications

Protected from host immune attack and antibiotic penetration by their unique cell envelope, mycobacterial pathogens cause devastating human diseases such as tuberculosis. Seamless coordination of cell growth with cell envelope elongation at the pole maintains this barrier. Unraveling this spatiotemporal regulation is a potential strategy for controlling mycobacterial infections. Our biochemical analysis previously revealed two functionally distinct membrane fractions in Mycobacterium smegmatis cell lysates: plasma membrane tightly associated with the cell wall (PM-CW) and a distinct fraction of pure membrane free of cell wall components (PMf). To provide further insight into the functions of these membrane fractions, we took the ...