Article
Microbiology
Miguel Diaz-Guerrero, Meztlli O. Gaytan, Eduardo Soto, Norma Espinosa, Elizabeth Garcia-Gomez, Arely Marcos-Vilchis, Angel Andrade, Bertha Gonzalez-Pedrajo
Summary: The type III secretion system (T3SS) is a complex molecular device that enables pathogenic bacteria to transport effector proteins directly into host cells. The CesL/SepL/SepD complex regulates the switch from translocator to effector secretion in enteropathogenic Escherichia coli, ensuring proper secretion and stability of the components involved. CesL also interacts with the cytoplasmic domains of export gate components, contributing to the regulation of substrate secretion.
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
Immunology
Shoichi Tachiyama, Ryan Skaar, Yunjie Chang, Brittany L. Carroll, Meenakumari Muthuramalingam, Sean K. Whittier, Michael L. Barta, Wendy L. Picking, Jun Liu, William D. Picking
Summary: Shigella flexneri, the causative agent of bacillary dysentery, utilizes a type III secretion system as its primary virulence factor to inject effector proteins into host cells. The cytoplasmic sorting platform of the injectisome, specifically the Spa33 pods, plays a critical role in substrate selection and secretion energizing. Through biophysical analyses, a model of Spa33 heterotrimers within the SP pods is proposed, suggesting how two distinct complexes come together to form complete pod structures during the recruitment of T3SS secretion substrates.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2021)
Review
Microbiology
Liam J. Worrall, Dorothy D. Majewski, Natalie C. J. Strynadka
Summary: This article describes two fascinating bacterial nanomachines - the widely distributed rotary flagellum and the eukaryotic cell-puncturing injectisome. Both nanomachines utilize the type III secretion system (T3SS) to secrete components and translocate proteins. Advances in structural and functional understanding, facilitated by cryoelectron microscopy technologies, have provided insights into these nanomachines since 2015.
ANNUAL REVIEW OF MICROBIOLOGY
(2023)
Review
Biology
Dipasree Hajra, Abhilash Vijay Nair, Dipshikha Chakravortty
Summary: Various Gram-negative bacteria possess a specialized membrane-bound protein secretion system known as the Type III secretion system (T3SS), which transports bacterial effector proteins into host cells to aid in pathogenesis. Studies have utilized various techniques to investigate the structure and function of T3SS and how different human pathogenic bacteria manipulate host systems to enhance virulence.
PHYSICS OF LIFE REVIEWS
(2021)
Article
Biochemistry & Molecular Biology
Bailey Milne-Davies, Stephan Wimmi, Andreas Diepold
Summary: The type III secretion system is the common core of two bacterial molecular machines: the flagellum and the injectisome. It is characterized by flexibility, adaptivity, and a dynamic nature.
MOLECULAR MICROBIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Julien R. C. Bergeron, Thomas C. Marlovits
Summary: The structure of double-membrane-spanning protein complexes, such as the T3SS, has long been a challenge in structural biology. However, the emergence of cryo-electron microscopy has transformed our understanding of this complex, allowing us to determine high-resolution structures and gain insights into its mechanism of substrate transport. This review summarizes the recent structures of T3SS components determined by cryo-EM, discusses the remaining regions to be characterized, and highlights the recent structural insights into the mechanism of effector transport. It also emphasizes the challenges that still need to be addressed.
CURRENT OPINION IN STRUCTURAL BIOLOGY
(2022)
Article
Microbiology
Hanh N. Lam, Tannia Lau, Adam Lentz, Jessica Sherry, Alejandro Cabrera-Cortez, Karen Hug, Annalyse Lalljie, Joanne Engel, R. Scott Lokey, Victoria Auerbuch
Summary: The development of new antibiotics is urgently needed due to the emerging threat of antibiotic-resistant bacteria. A newly discovered isomer, 4EpDN, shows potent inhibitory effects on multiple Gram-negative bacteria's injectisome type III secretion system (T3SS), possibly by preventing complete T3SS assembly.
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
(2021)
Review
Microbiology
Elizabeth A. Rucks
Summary: Type III secretion systems (T3SS) are utilized by Gram-negative pathogens to deliver effector proteins into target eukaryotic cells for manipulating cell functions and enhancing pathogenesis. This review will discuss the history, biochemical characterization, and function of chlamydial T3SS, as well as the use of heterologous/surrogate models for studying it. The review will also cover the history of chlamydial effectors and recent advances in the field.
MICROBIOLOGY AND MOLECULAR BIOLOGY REVIEWS
(2023)
Article
Immunology
Saskia Schott, Robina Scheuer, Francesca Ermoli, Timo Glatter, Elena Evguenieva-Hackenberg, Andreas Diepold
Summary: Many Gram-negative pathogens use type III secretion system (T3SS) to translocate virulence-promoting effector proteins into host cells. The activation of T3SS causes a reduction in bacterial growth and division known as secretion-associated growth inhibition (SAGI). In this study, a ParDE-like toxin-antitoxin system was identified on the virulence plasmid of Yersinia enterocolitica, which plays a role in the maintenance of virulence plasmid and reduction of plasmid loss. However, it is not directly involved in the SAGI or the activity of T3SS.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2023)
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)
Article
Biochemistry & Molecular Biology
Marta Nieckarz, Karolina Jaworska, Adrianna Raczkowska, Katarzyna Brzostek
Summary: This study investigates the role of the transcriptional regulator OmpR in membrane protein expression and secretion in Yersinia enterocolitica. The findings show that OmpR negatively affects the levels of Ysc-Yop proteins, particularly YopD, and represses the expression of yopD. OmpR also has a positive role in the expression of the master regulator of the flagellar-associated T3SS, flhDC.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Fisheries
Tao Liu, Zheng-Yang Zhou, Chen-wang Lu, Shang-Jie Bai, Jun Wang, Gao-Xue Wang
Summary: In this study, the researchers found that the T4SS of Yersinia ruckeri SC09 mediated bacterial virulence and immune evasion, possibly through the secretion of molecules such as STIR-1, STIR-2, and STIR-3. These findings contribute to a better understanding of the general rules of bacterial pathogenicity.
Article
Microbiology
Sukriti Prashar, Miguel Portales Guemes, Poorandai Shivbaran, Eugenia Jimenez Alvarez, Christopher Soha, Samir Nacer, Michael McDonough, Gregory Plano, Julie Torruellas Garcia
Summary: The research aimed to develop a novel disk diffusion assay to evaluate the susceptibility of Yersinia pestis to type III secretion system inhibitors using magnesium oxalate agar; the assay successfully detected inhibition of Y. pestis T3SS and may be useful for screening small molecules targeting bacterial T3SS or testing susceptibility to T3SS-targeting drugs.
MICROBIOLOGY SPECTRUM
(2021)
Review
Microbiology
Camilla Godlee, David W. Holden
Summary: The injectisome of Gram-negative bacterial pathogens injects virulence proteins into host cells, enabling invasion, replication, immune suppression, and transmission. This system secretes translocon proteins that form a pore in host cell membranes, allowing the delivery of effectors. Some effectors integrate into infected cell membranes, providing unique biochemical functions. This review focuses on the membrane integration mechanisms and functions of translocon proteins and effectors in mammalian bacterial pathogens.
