Vibrio vulnificus Secretes an Insulin-degrading Enzyme That Promotes Bacterial Proliferation in Vivo

Kim, In Hwang; Kim, Ik Jung; Wen, Yancheng; Park, Na Young; Park, Jin‐Young; Lee, Keun Woo; Koh, Ara; Lee, Ji Hyun; Koo, Seung Hoi; Kim, Kun-Soo

doi:10.1074/jbc.m115.656306

Cited by 7 publications

(5 citation statements)

References 48 publications

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“…Studies have shown that INS proteases have broad substrate specificity and are localized in the cytosol, peroxisomes, endosomes, and even on the surface of cells, perhaps as a reflection of the diverse biological functions of these enzymes (Laliberté and Carruthers, 2011). For example, Vibrio vulnificus secretes a novel insulinase, SidC, which contributes to the proliferation of this human bacterial pathogen (Kim et al, 2015). An M16A enzyme in yeasts, Ste23p, proteolyzes mammalian substrates Aβ1-40 and insulin B-chain (Alper et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Expression and Functional Studies of INS-5, an Insulinase-Like Protein in Cryptosporidium parvum

Jia

Guo

et al. 2020

Front. Microbiol.

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The small Cryptosporidium genome (∼9 Mb) has over 20 copies of genes encoding insulinase-like proteases (INS), suggesting that these enzymes may have important biological functions in the pathogen and could be developmentally regulated. In this study, INS-5, a unique member of the INS family in Cryptosporidium parvum, was cloned and expressed in Escherichia coli BL21 (DE3). In addition to the predicted INS-5 of ∼78 kDa, smaller fragments of ∼70, ∼55, and ∼30 kDa were simultaneously generated. After purification through a nickel-nitrilotriacetic acid affinity column, the full recombinant protein obtained was used to prepare polyclonal antibodies. Antibodies raised against INS-5 recognized the recombinant protein and native protein in sporozoite extracts. Further characterization of INS-5 included qRT-PCR assessment of gene expression; immunofluorescence localization of the protein expression in sporozoites, merozoites, and other developmental stages; and neutralization of invasion of C. parvum in vitro. The results obtained indicated that although INS-5 was expressed in sporozoites and merozoites, the high gene expression was from 36 to 48 h of the in vitro culture after invasion. Anti-INS-5 antibodies partially neutralized the invasion (inhibition rate = 38.5%). Results of this study suggest that INS-5 plays some role in the invasion and growth of C. parvum.

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Section: Introductionmentioning

confidence: 99%

Expression and Functional Studies of INS-5, an Insulinase-Like Protein in Cryptosporidium parvum

Jia

Guo

et al. 2020

Front. Microbiol.

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“…Most patients have underlying diseases, particularly chronic liver disorders, and the mortality rate may exceed 50% [ 3 ]. A number of virulence factors have been identified in V. vulnificus , including capsular polysaccharides [ 4 ], iron-acquisition ability [ 5 , 6 ], flagellum [ 7 ], type IV pili [ 8 ], extracellular insulin-degrading enzyme [ 9 ] and an RTX (repeats in toxin) cytotoxin [ 10 – 12 ].…”

Section: Introductionmentioning

confidence: 99%

Vibrio vulnificus MARTX cytotoxin causes inactivation of phagocytosis-related signaling molecules in macrophages

et al. 2017

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Background Vibrio vulnificus is a marine bacterial species that causes opportunistic infections manifested by serious skin lesions and fulminant septicemia in humans. We have previously shown that the multifunctional autoprocessing repeats in toxin (MARTXVv1) of a biotype 1 V. vulnificus strain promotes survival of this organism in the host by preventing it from engulfment by the phagocytes. The purpose of this study was to further explore how MARTXVv1 inhibits phagocytosis of this microorganism by the macrophage.MethodsWe compared between a wild-type V. vulnificus strain and its MARTXVv1-deficient mutant for a variety of phagocytosis-related responses, including morphological change and activation of signaling molecules, they induced in the macrophage. We also characterized a set of MARTXVv1 domain-deletion mutants to define the regions associated with antiphagocytosis activity.ResultsThe RAW 264.7 cells and mouse peritoneal exudate macrophages underwent cell rounding accompanied by F-actin disorganization in the presence of MARTXVv1. In addition, phosphorylation of some F-actin rearrangement-associated signaling molecules, including Lyn, Fgr and Hck of the Src family kinases (SFKs), focal adhesion kinase (FAK), proline-rich tyrosine kinase 2 (Pyk2), phosphoinositide 3-kinase (PI3K) and Akt, but not p38, was decreased. By using specific inhibitors, we found that these kinases were all involved in the phagocytosis of MARTXVv1-deficient mutant in an order of SFKs-FAK/Pyk2-PI3K-Akt. Deletion of the effector domains in the central region of MARTXVv1 could lead to reduced cytotoxicity, depending on the region and size of deletion, but did not affect the antiphagocytosis activity and ability to cause rounding of macrophage. Reduced phosphorylation of Akt was closely associated with inhibition of phagocytosis by the wild-type strain and MARTXVv1 domain-deletion mutants, and expression of the constitutively active Akt, myr-Akt, enhanced the engulfment of these strains by macrophage.ConclusionsMARTXVv1 could inactivate the SFKs-FAK/Pyk2-PI3K-Akt signaling pathway in the macrophages. This might lead to impaired phagocytosis of the V. vulnificus-infected macrophage. The majority of the central region of MARTXVv1 is not associated with the antiphagocytosis activity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12929-017-0368-2) contains supplementary material, which is available to authorized users.

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“…In the dataset collected from sample B, predominantly proteases from S. aureus were identified including collagenases, the beta-lactamase regulator BlaR1, class C beta-lactamase, the extracellular adherence protein homolog EapH2 and a caseinolytic protease (Clp) involved in the degradation of damaged proteins. Furthermore, the sample from Patient B metagenome encoded pitrilysin, which degrades small peptides and contributes for instance to the pathogenicity of Vibrio vulnificus through the proteolytic degradation of insulin [ 67 ], and mirabilysin from P. mirabilis , which is an IgA-degrading metalloprotease [ 68 ].…”

Section: Resultsmentioning

confidence: 99%

First Description of the Composition and the Functional Capabilities of the Skin Microbial Community Accompanying Severe Scabies Infestation in Humans

et al. 2021

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Epidemiological studies link Sarcoptes scabiei infection and impetigo. Scabies mites can promote Streptococcus pyogenes (Group A Streptococcus) and Staphylococcus aureus infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. However, little is known about the composition and the function of the scabies-associated microbiota. Here, high-throughput whole-metagenome sequencing was used to explore the scabies-associated microbiome. Scabies mites including their immediate microenvironments were isolated from two patients with severe scabies in Northern Australia. Two ~45–50 million paired-end reads Illumina libraries were generated of which ~2 (5.1%) and 0.7 million (1.3%) microbial reads were filtered out by mapping to human (hg19) and mite draft genomes. Taxonomic profiling revealed a microbial community dominated by the phylum Firmicutes (A: 79% and B: 59%) and genera that comprise Streptococcus, Staphylococcus, Acinetobacter, and Corynebacterium. Assembly of the metagenome reads resulted in genome bins representing reference genomes of Acinetobacter baumannii, Streptococcus dysgalactiae (Group C/G), Proteus mirablis and Staphylococcus aureus. The contigs contained genes relevant to pathogenicity and antibiotics resistance. Confocal microscopy of a patient skin sample confirmed A. baumannii, Streptococci and S. aureus in scabies mite gut and faeces and the surrounding skin. The study provides fundamental evidence for the association of opportunistic pathogens with scabies infection.

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Vibrio vulnificus Secretes an Insulin-degrading Enzyme That Promotes Bacterial Proliferation in Vivo

Cited by 7 publications

References 48 publications

Expression and Functional Studies of INS-5, an Insulinase-Like Protein in Cryptosporidium parvum

Expression and Functional Studies of INS-5, an Insulinase-Like Protein in Cryptosporidium parvum

Vibrio vulnificus MARTX cytotoxin causes inactivation of phagocytosis-related signaling molecules in macrophages

First Description of the Composition and the Functional Capabilities of the Skin Microbial Community Accompanying Severe Scabies Infestation in Humans

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