Article
Multidisciplinary Sciences
Eduardo Soto, Jorge E. Galan, Marfa Lara-Tejero
Summary: In this study, an extensive in vivo cross-linking strategy aided by structure modeling was used to investigate the sorting platform complex of type III secretion systems. The assembly process of this bacterial structure was mapped using identified cross-links as signatures for pairwise intersubunit interactions and systematic genetic deletions. Insights generated by this study could be used for the rational development of antivirulence strategies against medically important bacterial pathogens.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Review
Environmental Sciences
Sajjad Hussain, Ping Ouyang, Yingkun Zhu, Abdul Khalique, Changliang He, Xiaoxia Liang, Gang Shu, Lizi Yin
Summary: The failure of traditional vaccination against Salmonella necessitates the development of novel therapeutics. Understanding the role of T3SS in bacterial pathogenesis and the development of anti-virulence agents is crucial, and the inhibition of T3SS at different stages of infection can help in controlling the disease progression. Insights into T3SS inhibitors of Salmonella can mitigate antibiotic resistance and lead to the development of new therapeutics.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Biochemistry & Molecular Biology
Nidhi Singh, Thales Kronenberger, Andrea Eipper, Felix Weichel, Mirita Franz-Wachtel, Boris Macek, Samuel Wagner
Summary: The study found that the salt bridges in the assembly of virulence-associated T3SS are not critical, but facilitate the incorporation of the next subunit. The conserved charged residues are crucial for type III-dependent secretion and play a key role in the function of T3SS.
JOURNAL OF MOLECULAR BIOLOGY
(2021)
Article
Pharmacology & Pharmacy
Yonghui Wang, Meihui Hou, Zhaodong Kan, Guanghui Zhang, Yunxia Li, Lei Zhou, Changfa Wang
Summary: Three type III secretion system inhibitors were identified through virtual screening and biological evaluation, showing potential as lead molecules for anti-Salmonella drug development. These compounds exhibited comparable activity to the positive control gatifloxacin against Salmonella abortus equi strains.
FRONTIERS IN PHARMACOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Lisa Ann Burdette, Han Teng Wong, Danielle Tullman-Ercek
Summary: In this study, the effects of different components in the growth medium on protein secretion titer were investigated. It was found that the optimal combination of carbon sources, buffers, and salts significantly increased secretion titer. This work demonstrates the importance of optimizing medium composition to enhance protein secretion titer in bacteria.
MICROBIAL CELL FACTORIES
(2021)
Article
Biochemistry & Molecular Biology
Julia Aguilera-Herce, Concepcion Panadero-Medianero, Maria Antonia Sanchez-Romero, Roberto Balbontin, Joaquin Bernal-Bayard, Francisco Ramos-Morales
Summary: Type III secretion systems are commonly found in many Gram-negative pathogens and symbionts. Salmonella enterica possess two type III secretion systems associated with virulence, one for host cell invasion and another for intracellular niche maintenance. This study investigates the biochemical function of the SrfJ effector and its impact on mammalian host cells. The results indicate that SrfJ acts as a glucosylceramidase, altering the lipidome and transcriptome of host cells, both in epithelial cells and macrophages during Salmonella infection. Furthermore, analysis of gene expression changes suggests that SrfJ may play a role in protecting Salmonella from host immune defenses.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biotechnology & Applied Microbiology
Julie Ming Liang, Lisa Ann Burdette, Han Teng Wong, Danielle Tullman-Ercek
Summary: Protein production using bacteria is costly and inefficient. Researchers have engineered a bacterial secretion system to improve the production process by directly secreting soluble proteins into the culture media. They explored different activation methods and created strains capable of efficiently producing heterologous proteins. They also discovered a genetic relationship between T3SS regulators, hilE and hilD, further enhancing the industrial competitiveness of protein production strains.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2023)
Article
Microbiology
Marinos Kalafatis, James M. Slauch
Summary: This study reveals the mechanism of H-NS regulation in controlling the Salmonella pathogenicity island 1 (SPI1) and genetically demonstrates that HilD is able to overcome the inhibitory effect of H-NS on SPI1.
JOURNAL OF BACTERIOLOGY
(2021)
Article
Plant Sciences
Irene Jimenez-Guerrero, Francisco Javier Lopez-Baena, Carlos Medina
Summary: Rhizobia establish mutually beneficial interactions with legume plants through nodulation, where the bacteria fix atmospheric nitrogen. The compatibility of this interaction is determined by bacterial recognition of flavonoids secreted by plants, which trigger the synthesis of Nod factors. Other bacterial signals, such as extracellular polysaccharides and secreted proteins, also contribute to the efficiency of the interaction.
Article
Multidisciplinary Sciences
Qing Li, Liren Zhang, Wenhua You, Jiali Xu, Jingjing Dai, Dongxu Hua, Ruizhi Zhang, Feifan Yao, Suiqing Zhou, Wei Huang, Yongjiu Dai, Yu Zhang, Tasiken Baheti, Xiaofeng Qian, Liyong Pu, Jing Xu, Yongxiang Xia, Chuanyong Zhang, Jinhai Tang, Xuehao Wang
Summary: This study demonstrates that the PRDM1-USP22-SPI1 axis regulates PD-L1 levels, resulting in exhausted infiltrated CD8(+) T cells in hepatocellular carcinoma (HCC). Combining PRDM1 overexpression with PD-(L)1 monoclonal antibody treatment provides a therapeutic strategy for HCC treatment.
NATURE COMMUNICATIONS
(2022)
Article
Biology
Owain J. Bryant, Paraminder Dhillon, Colin Hughes, Gillian M. Fraser
Summary: In addition to the gate recognition motif (GRM), a hydrophobic N-terminal signal is identified on flagellar rod and hook subunits, which are separately and sequentially recognized by the flagellar export machinery. The hydrophobic N-terminal signal may trigger the opening of the flagellar export gate.
Article
Microbiology
B. Izquierdo Lafuente, R. Ummels, C. Kuijl, W. Bitter, A. Speer
Summary: CpnT, a potent secreted toxin of Mycobacterium tuberculosis, is exclusively secreted by the ESX-5 system in bacterial culture but relies on intact ESX-1, ESX-4, and ESX-5 systems during infection studies. This highlights the intricate interplay of three different secretion systems in secreting one substrate during infection.
Article
Engineering, Marine
Florent Birrien, Tom Baldock
Summary: An equilibrium beach profile model was developed and coupled with a parametric hydrodynamic model to provide feedback between morphology and hydrodynamics. The model was compared to laboratory profiles and showed accurate predictions for erosive and accretive conditions, with potential for improvement in linking dissipation and local transport.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Biotechnology & Applied Microbiology
Silja Vaelimets, Patricia Pedetti, Ludovika Jessica Virginia, Mai Ngoc Hoang, Michael Sauer, Clemens Peterbauer
Summary: Small laccases from Streptomyces coelicolor, Streptomyces viridosporus, and Amycolatopsis 75iv2 were successfully expressed in both Gram-positive expression hosts B. subtilis and S. lividans. However, the extracellular activities of the laccases were significantly higher in S. lividans compared to B. subtilis.
MICROBIAL CELL FACTORIES
(2023)
Article
Microbiology
Jordan J. Hendriksen, Hee Jung Lee, Alexander J. Bradshaw, Keiichi Namba, Fabienne F. V. Chevance, Tohru Minamino, Kelly T. Hughes
Summary: The bacterial flagellum is a highly complex molecular machine consisting of multiple components, including the adaptor protein FIiE. This protein plays a crucial role in connecting different parts of the flagellar machinery, such as the MS-ring, the core T3S secretion complex, and the axial structure, to facilitate flagellum assembly and function. This study combined genetic analysis with structural data to provide insights into the essential role of FIiE in the flagellum.
Article
Biochemistry & Molecular Biology
Yumi Iwadate, Rouhallah Ramezanifard, Yekaterina A. Golubeva, Luke A. Fenlon, James M. Slauch
Summary: The inner membrane protein PaeA is essential for reducing cytoplasmic cadaverine and putrescine concentrations under certain stress conditions, providing important protection for cells.
MOLECULAR MICROBIOLOGY
(2021)
Review
Genetics & Heredity
Saniya Deshmukh, Supreet Saini
FRONTIERS IN GENETICS
(2020)
Article
Cell Biology
Xingchen Dong, Xiangming Hu, Yan Bao, Guo Li, Xiao-Dong Yang, James M. Slauch, Lin-Feng Chen
Summary: The study demonstrates that Brd4 plays a crucial role in regulating NLRC4 inflammasome activation during Salmonella typhimurium infection, by maintaining the expression of Naips. Deficiency of Brd4 leads to impaired inflammasome-dependent cytokine release and pyroptosis, highlighting a novel function of Brd4 in innate immunity against bacterial pathogens.
JOURNAL OF CELL BIOLOGY
(2021)
Article
Microbiology
Marinos Kalafatis, James M. Slauch
Summary: This study reveals the mechanism of H-NS regulation in controlling the Salmonella pathogenicity island 1 (SPI1) and genetically demonstrates that HilD is able to overcome the inhibitory effect of H-NS on SPI1.
JOURNAL OF BACTERIOLOGY
(2021)
Article
Microbiology
Dibyendu Dutta, Supreet Saini
Summary: This study presents a model combining gene expression stochasticity and metabolite exchange to explain the growth advantage of cooperative microbial populations, predicting the impact of metabolite exchange on cell growth, and elucidating why reciprocal auxotrophic pairs can grow faster through exchanging metabolites.
Article
Microbiology
Fatih Cakar, Yekaterina A. Golubeva, Carin K. Vanderpool, James M. Slauch
Summary: This study elucidates the impact of sRNA MicC on the expression of the SPI1 system, adding to our understanding of the complex regulatory network controlling SPI1 expression.
JOURNAL OF BACTERIOLOGY
(2022)
Article
Microbiology
Anjali Mahilkar, Pavithra Venkataraman, Akshat Mall, Supreet Saini
Summary: Environmental cues in an ecological niche are often temporary in nature, leading bacteria to exhibit anticipatory regulation as an adaptive response. Through experimental evolution, it has been shown that growth in cyclical environments can lead to the evolution of anticipatory regulation.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Rajeshkannan, Anjali Mahilkar, Supreet Saini
Summary: The GAL network in yeast is a well-characterized regulatory network that controls the expression of GAL genes based on exposure to galactose and the combination of regulatory genes GAL3, GAL1, GAL80, and GAL4. This network is unique due to the presence of multiple regulatory factors, and recent research suggests that the behavior and gene expression of yeast cells can be modulated by altering the binding affinities between these regulatory proteins. This adaptability may explain the presence of multiple GAL regulatory alleles discovered in ecological isolates.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2022)
Editorial Material
Multidisciplinary Sciences
James M. Slauch
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Ecology
Anjali Mahilkar, Prachitha Nagendra, Phaniendra Alugoju, E. Rajeshkannan, Supreet Saini
Summary: This study investigates the adaptive diversification of yeast in an environment containing melibiose as the carbon source. The results show that mutations in the GAL3 gene, involved in metabolic co-operation, drive the adaptive diversification. The study demonstrates the importance of metabolic co-operation with public resources in generating biological diversity.
Article
Multidisciplinary Sciences
Anjali Mahilkar, Namratha Raj, Sharvari Kemkar, Supreet Saini
Summary: Mutations provide the raw material for natural selection, and understanding the diversity and frequency of mutations is crucial for understanding genetic diversity in a population. Mutation accumulation experiments can estimate mutation rates, distribution of fitness effects, and mutation spectrum. The results show that the proportion of beneficial mutations in an MA experiment is over-represented, and the fitness effects of beneficial and deleterious mutations are inaccurately represented. An MA experiment with E. coli also demonstrates the impact of selection in a growing colony on experiment results.
SCIENTIFIC REPORTS
(2022)
Article
Microbiology
Sabrina Z. Z. Abdulla, Kyungsub Kim, Muhammad S. S. Azam, Yekaterina A. A. Golubeva, Fatih Cakar, James M. M. Slauch, Carin K. K. Vanderpool
Summary: This study found that two sRNAs (SdsR and Spot42) regulate SPI-1 by targeting different regions of the hilD mRNA 3' UTR. These sRNAs increase hilD mRNA levels by interfering with RNase E-dependent mRNA degradation, thus enhancing Salmonella invasiveness.
JOURNAL OF BACTERIOLOGY
(2023)
Article
Microbiology
Yumi Iwadate, Yekaterina A. A. Golubeva, James M. M. Slauch
Summary: Polyamines and Mg2+ levels are coordinately regulated for viability under low and high concentrations of polyamines. Polyamine synthesis is induced under Mg2+ starvation and the high-affinity Mg2+ transporters MgtA and MgtB are produced. Either polyamine synthesis or Mg2+ transport is required for viability. The excess polyamines must be excreted once Mg2+ levels are reestablished. Sensitivity to high concentrations of polyamines is proportional to the Mg2+ levels. These results are also observed during infection. Polyamine synthesis mutants and strains lacking the MgtB Mg2+ transporter are attenuated in a mouse model of systemic infection.
Article
Multidisciplinary Sciences
Anjali Mahilkar, Prachitha Nagendra, Supreet Saini
Summary: Saccharomyces cerevisiae is widely used as a model organism in genetics, evolution, and molecular biology. It has also gained popularity as a model organism for studying speciation. The yeast life cycle involves both asexual and sexual reproductive phases, making it suitable for studying the evolution of reproductive barriers. The mating efficiency between two mating types can indicate the extent of reproductive isolation between haploids. A simple and reproducible protocol is presented here to quantify the mating efficiency.
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
(2022)
Article
Microbiology
Rouhallah Ramezanifard, Yekaterina A. Golubeva, Alexander D. Palmer, James M. Slauch
Summary: The TamAB system, regulated by the PhoPQ two-component system, is induced in macrophages to compensate for the stressed beta-barrel protein assembly complex, Bam, under conditions mimicking the macrophage phagosome. Mutations affecting TamAB and Bam confer synthetic phenotypes in animals, macrophages, and in vitro, suggesting their importance in outer membrane homeostasis and Salmonella's adaptation and reproduction within the macrophage phagosome.
JOURNAL OF BACTERIOLOGY
(2023)