Molecular characterization and assembly of the needle complex of the
            <i>Salmonella typhimurium</i>
            type III protein secretion system

Kubori, Tomoko; Sukhan, Anand; Aizawa, Shin‐Ichi; Galán, Jorge E.

doi:10.1073/pnas.170128997

Cited by 314 publications

(357 citation statements)

References 29 publications

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“…The structure of this apparatus from Shigella and Salmonella resembles a needle, which probably functions to allow transport across the inner and outer membranes of the bacteria and into the cytoplasm of the host cell (Blocker et al, 1999;Kubori et al, 2000;Tamano et al, 2000). One model suggests that the Yops function in part to prevent a pore from forming in the host cell plasma membrane resulting from insertion of the apparatus.…”

Section: Yops Target Mammalian Signalling Pathways 205mentioning

confidence: 99%

Yersinia effectors target mammalian signalling pathways

2002

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SummaryAnimals have an immune system to fight off challenges from both viruses and bacteria. The first line of defence is innate immunity, which is composed of cells that engulf pathogens as well as cells that release potent signalling molecules to activate an inflammatory response and the adaptive immune system. Pathogenic bacteria have evolved a set of weapons, or effectors, to ensure survival in the host. Yersinia spp. use a type III secretion system to translocate these effector proteins, called Yops, into the host. This report outlines how Yops thwart the signalling machinery of the host immune system. Introduction Innate immunity and signallingInnate immunity is the first line of defence against bacterial and viral infection (for a review of innate immunity, see Medzhitov and Janeway, 2000). The cells involved in the immune response use a wide variety of signalling cascades to activate processes such as phagocytosis, cytokine production and release and production of reactive oxygen species. In addition to eliminating pathogens, the innate immune system activates the adaptive immune response through the presentation of foreign peptides to T cells.Phagocytosis is an essential component of the innate immune system (May and Machesky, 2001). Rearrangement of the actin cytoskeleton during phagocytosis is mediated by the recruitment of proteins that function in actin rearrangement; these include paxillin, p130Cas and focal adhesion kinase (FAK) (Greenberg et al., 1990;Allen and Aderem, 1996). These proteins may form through M cells (microfold cells), which are specialized cells that take up foreign antigens, in intestinal Peyer's patches (Autenrieth and Firsching, 1996). Recognition of Yersinia by M cells is mediated via b1 integrins on the M-cell plasma membrane and the invasin protein of Yersinia (Marra and Isberg, 1997;Clark et al., 1998). Once Yersinia has penetrated the M cells, it can localize in the lymphoid tissue of its host.The recently sequenced genome of Y. pestis (Parkhill et al., 2001) suggests that many of the genes that Yersinia uses during infection and invasion, including adhesins, secretion systems and insecticidal toxins, have been acquired from other bacteria and viruses. Furthermore, all three pathogenic species of Yersinia harbour an extrachromosomal plasmid of 70 kb that is essential for virulence (Portnoy and Martinez, 1985). This plasmid contains the genes of a type III secretion system, a translocation apparatus highly conserved among pathogenic Gram-negative bacteria (for a review, see Cornelis, 1998). This secretion system is responsible for the translocation of the Yersinia effectors, termed Yops, into the host cell. Once inside the host cell, Yops carry out disruption of signalling cascades that activate the processes of phagocytosis, cytokine release and respiratory burst. Six Yop effectors have been identified (YopH, YopE, YopJ/P, YpkA/YopO, YopT and YopM). Some of these effectors are known to function in the downregulation of critical signalling cascades of the immune system (Fig...

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Section: Yops Target Mammalian Signalling Pathways 205mentioning

confidence: 99%

Yersinia effectors target mammalian signalling pathways

2002

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“…It consists of a 12-14-mer of a protein belonging to the YscC family of secretins ( Figure 1) (Koster et al, 1997;Kubori et al, 2000;Tamano et al, 2000;Blocker et al, 2001;Burghout et al, 2004b). Secretins are found not only in injectisomes but also in the type II secretion apparatus, in type IV pili (Collins et al, 2004;Chami et al, 2005) as well as in filamentous phages (Russel, 1994).…”

Section: The Om-ringsmentioning

confidence: 99%

“…However, attempts to dock the EscJ structure into the recent cryo-EM map of the S. flexneri NC, suggest that MxiJ might rather be a 12-mer (Hodgkinson et al, 2009). A protein from the less-conserved YscD (Yersinia)/PrgH (S. enterica)/MxiC (S. flexneri) family is proposed to participate in the IM-ring formation (Kubori et al, 2000) and possibly to Brought to you by | Universitaetsbibliothek Basel Authenticated Download Date | 11/9/17 5:13 PM connect the IM-and OM-rings (Spreter et al, 2009). The structure of the periplasmic domain of PrgH reveals strong similarity to the EscJ/PrgK IM-ring component and to the periplasmic domain of the secretin (Spreter et al, 2009).…”

Section: The Im-ring and The Connectormentioning

confidence: 99%

“…Some indirect biochemical and EM evidence suggests that, in S. enterica SPI-1, PrgJ forms such an 'inner rod' structure (Kubori et al, 2000;Sukhan et al, 2003;Marlovits et al, 2004). There is no Yersinia Ysc homolog of PrgJ but YscI has properties similar to those of the needle subunit.…”

Section: A Rod?mentioning

confidence: 99%

“…It is constructed via the helical polymerization of approximately 150 subunits of the YscF family (Kubori et al, 2000;Hoiczyk and Blobel, 2001). …”

Section: The Needlementioning

confidence: 99%

See 2 more Smart Citations

The type III secretion injectisome, a complex nanomachine for intracellular ‘toxin’ delivery

Cornelis

2010

Biological Chemistry

107

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The type III secretion injectisome is a nanomachine that delivers bacterial proteins into the cytosol of eukaryotic target cells. It consists of a cylindrical basal structure spanning the two bacterial membranes and the peptidoglycan, connected to a hollow needle, eventually followed by a filament (animal pathogens) or to a long pilus (plant pathogens). Export employs a type III pathway. During assembly, all the protein subunits of external elements are sequentially exported by the basal structure itself, implying that the export apparatus can switch its substrate specificity over time. The length of the needle is controlled by a protein that it also secreted during assembly and presumably acts as a molecular ruler.

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The sorting platform in the type III secretion pathway: From assembly to function

Soto

Lara‐Tejero

2023

BioEssays

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The type III secretion system (T3SS) is a specialized nanomachine that enables bacteria to secrete proteins in a specific order and directly deliver a specific set of them, collectively known as effectors, into eukaryotic organisms. The core structure of the T3SS is a syringe‐like apparatus composed of multiple building blocks, including both membrane‐associated and soluble proteins. The cytosolic components organize together in a chamber‐like structure known as the sorting platform (SP), responsible for recruiting, sorting, and initiating the substrates destined to engage this secretion pathway. In this article, we provide an overview of recent findings on the SP's structure and function, with a particular focus on its assembly pathway. Furthermore, we discuss the molecular mechanisms behind the recruitment and hierarchical sorting of substrates by this cytosolic complex. Overall, the T3SS is a highly specialized and complex system that requires precise coordination to function properly. A deeper understanding of how the SP orchestrates T3S could enhance our comprehension of this complex nanomachine, which is central to the host‐pathogen interface, and could aid in the development of novel strategies to fight bacterial infections.

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Molecular characterization and assembly of the needle complex of the Salmonella typhimurium type III protein secretion system

Cited by 314 publications

References 29 publications

Yersinia effectors target mammalian signalling pathways

Yersinia effectors target mammalian signalling pathways

The type III secretion injectisome, a complex nanomachine for intracellular ‘toxin’ delivery

The sorting platform in the type III secretion pathway: From assembly to function

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