IcsA is an outer membrane protein in the autotransporter family that is required for Shigella flexneri pathogenesis. Following its secretion through the Sec translocon, IcsA is incorporated into the outer membrane in a process that depends on YaeT, a component of an outer membrane beta-barrel insertion machinery. We investigated the role of the periplasmic chaperone Skp in IcsA maturation. Skp ...

Shigella species are the causative agents of human bacillary dysentery. These bacteria spread within the lining of the gut via a process termed actin-based motility whereby an actin 'tail' is formed at the bacterial pole. The bacterial outer membrane protein IcsA initiates this process, and crucially is precisely positioned on the bacterial polar surface. Lipopolysaccharide (LPS) O-antigen surf...

A quantitative method for circulating islet cell surface antibodies (ICSA), based on the binding of 125I-protein A to insulin-producing RINm5F cells, was used to evaluate ICSA in plasma of 4- to 40-week-old Aston obese hyperglycaemic (ob/ob) mice and normal control (+/+) mice. RINm5F cells bound 2502 +/- 1196 c.p.m. 125I-protein A per 10(5) cells (mean +/- S.D., n = 54) after incubation with +/...

The Shigella flexneri IcsA (VirG) protein is a polarly distributed outer membrane protein that is a fundamental virulence factor which interacts with neural Wiskott-Aldrich syndrome protein (N-WASP). The activated N-WASP then activates the Arp2/3 complex which initiates de novo actin nucleation and polymerisation to form F-actin comet tails and allows bacterial cell-to-cell spreading. In a prev...

OHGAWARA, H. and HIRATA, Y. Islet Cell Surface Antibodies in Diabetes and Their Possible Influence on Glucose Tolerance. Tohoku J. exp. Med., 1984, 142 (2), 211-216 The prevalence of islet cell surface antibodies (ICSA) in patients with insulin-dependent (IDD), noninsulin-dependent (NIDD) or newly-diagnosed diabetes mellitus was studied. The antibodies were present in 14 (27%) of 15 IDD patient...

Proper protein localization is critical for bacterial virulence. PhoN2 is a virulence-associated ATP-diphosphohydrolase (apyrase) involved in IcsA-mediated actin-based motility of S. flexneri. Herein, by analyzing a ΔphoN2 mutant of the S. flexneri strain M90T and by generating phoN2::HA fusions, we show that PhoN2, is a periplasmic protein that strictly localizes at the bacterial poles, with a...

The generation and maintenance of subcellular organization in bacteria is critical for many cell processes and properties, including growth, structural integrity and, in pathogens, virulence. Here, we investigate the mechanisms by which the virulence protein IcsA (VirG) is distributed on the bacterial surface to promote efficient transmission of the bacterium Shigella flexneri from one host cel...

We previously demonstrated that central apneas during sleep in patients with idiopathic central sleep apnea (ICSA) are triggered by abrupt hyperventilation. In addition, baseline PCO2 at the time of augmented breaths which triggered central apneas was lower than for augmented breaths which did not trigger apneas. These observations led us to hypothesize that patients with ICSA chronically hyper...

introduction: shigella is a facultative intracellular pathogen that uses the host actin cytoskeleton protein for intra- and intercellular spread. the aim of this study was to determine the distribution of icsa gene and icsa expressed protein bands among shigella flexneri strains isolated from 3 clinical centers in tehran. material and methods: two hundred and seventy five isolated shigella flex...

The IcsA (intracellular spread gene A) autotransporter from Shigella flexneri is a key virulence factor. We identified a stable fragment comprising residues 591 to 758, which corresponds to the autochaperone region of the IcsA passenger domain. We showed that thermal unfolding of the autochaperone region is reversible and determined its crystal structure at 2.0-Å resolution.