Genetic Analysis of Type E Botulinum Toxin-Producing
            <i>Clostridium butyricum</i>
            Strains

Wang, Xingmin; Maegawa, Tsuneo; Karasawa, Tadahiro; Kozaki, Shunji; Tsukamoto, Kentaro; Gyobu, Yotaku; Yamakawa, Kiyotaka; Oguma, Keiji; Sakaguchi, Yoshihiko; Nakamura, Shinichi

doi:10.1128/aem.66.11.4992-4997.2000

Cited by 63 publications

(49 citation statements)

References 14 publications

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“…HAmu-mediated fusion is thought to be independent of receptor binding (3). The class II FM that we tested was the Sindbis virus glycoprotein from the alphavirus family (22) and is designated as SIN. SIN consists of two transmembrane proteins (23), one responsible for fusion (E1) and the other for cell binding (E2).…”

Section: Construction Of Ph-dependent Fusogenmentioning

confidence: 99%

Targeting lentiviral vectors to specific cell types in vivo

Yang

Bailey

Baltimore

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

143

165

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We have developed an efficient method to target lentivirusmediated gene transduction to a desired cell type. It involves incorporation of antibody and fusogenic protein as two distinct molecules into the lentiviral surface. The fusogen is constructed by modifying viral envelope proteins, so that they lack the ability to bind to their cognate receptor but still retain the ability to trigger pH-dependent membrane fusion. Thus, the specificity of such a lentiviral vector is solely determined by the antibody, which is chosen to recognize a specific surface antigen of the desired cell type. This specific binding then induces endocytosis of the surface antigen, bringing the lentivirus into an endosome. There, the fusogen responds to the low pH environment and mediates membrane fusion, allowing the virus core to enter the cytosol. Using CD20 as a target antigen for human B cells, we have demonstrated that this targeting strategy is effective both in vitro and in intact animals. This methodology is flexible and can be extended to other forms of cell type-specific recognition to mediate targeting. The only requirement is that the antibody (or other binding protein) must be endocytosed after interaction with its cell surface-binding determinant.antibody ͉ gene therapy ͉ lentivirus ͉ retrovirus ͉ targeted gene delivery

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Section: Construction Of Ph-dependent Fusogenmentioning

confidence: 99%

Targeting lentiviral vectors to specific cell types in vivo

Yang

Bailey

Baltimore

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

143

165

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“…LRP has also been identified as the receptor for the cellular prion protein (26 -28) and certain alphaviruses including Sindbis and Venezuelan equine encephalitis virus (29,30). However, this is the first demonstration that LRP acts as a cellular receptor for bacterial toxin in activation of RhoA and enhancement of bacterial uptake.…”

Section: Figmentioning

confidence: 99%

37-kDa Laminin Receptor Precursor Modulates Cytotoxic Necrotizing Factor 1–mediated RhoA Activation and Bacterial Uptake

Chung

Hong

Kim

et al. 2003

Journal of Biological Chemistry

109

124

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Cytotoxic necrotizing factor 1 (CNF1) is a bacterial toxin known to activate Rho GTPases and induce host cell cytoskeleton rearrangements. The constitutive activation of Rho GTPases by CNF1 is shown to enhance bacterial uptake in epithelial cells and human brain microvascular endothelial cells. However, it is unknown how exogenous CNF1 exhibits such phenotypes in eukaryotic cells. Here, we identified 37-kDa laminin receptor precursor (LRP) as the receptor for CNF1 from screening the cDNA library of human brain microvascular endothelial cells by the yeast two-hybrid system using the N-terminal domain of CNF1 as bait. CNF1-mediated RhoA activation and bacterial uptake were inhibited by exogenous LRP or LRP antisense oligodeoxynucleotides, whereas they were increased in LRPoverexpressing cells. These findings indicate that the CNF1 interaction with LRP is the initial step required for CNF1-mediated RhoA activation and bacterial uptake in eukaryotic cells.

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“…Type A2 and F strains have orfx2, orfx1, and p47 genes similar to those of type E but with a regulator gene, botR, located between the orfx1 and p47 genes (15). Recently, a new gene, orfx3, in addition to the complete orfx2 gene, was identified in types A1 and A2 (4).The nucleotide sequence of bont/E has been published for 36 strains (11,22,28,30). BoNTs are composed of a light chain (ϳ50 kDa) and a heavy chain (ϳ100 kDa), linked by a disulfide bond.…”

mentioning

confidence: 99%

“…The nucleotide sequence of bont/E has been published for 36 strains (11,22,28,30). BoNTs are composed of a light chain (ϳ50 kDa) and a heavy chain (ϳ100 kDa), linked by a disulfide bond.…”

mentioning

confidence: 99%

Sequencing the Botulinum Neurotoxin Gene and Related Genes in Clostridium botulinum Type E Strains Reveals orfx3 and a Novel Type E Neurotoxin Subtype

et al. 2007

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Three Clostridium botulinum type E strains were sequenced for the botulinum neurotoxin (BoNT) gene cluster, and 11 type E strains, representing a wide biodiversity, were sequenced for the bont/E gene. The total length of the BoNT/E gene cluster was 12,908 bp, and a novel gene (partial) designated orfx3, together with the complete orfx2 gene, was identified in the three type E strains for the first time. Apart from orfx3, the structure and organization of the neurotoxin gene cluster of the three strains were identical to those of previously published ones. Only minor differences (<3%) in the nucleotide sequences of the gene cluster components were observed among the three strains and the published BoNT/E-producing clostridia. The orfx3, orfx2, orfx1, and p47 gene sequences of the three type E strains shared homologies of 81%, 67 to 76%, 78 to 79%, and 79 to 85%, respectively, with published sequences for type A1 and A2 C. botulinum. Analysis of bont/E from the 14 type E strains and 19 previously published BoNT/E-producing clostridia revealed six neurotoxin subtypes, with a new distinct subtype consisting of three Finnish isolates alone. The amino acid sequence of the subtype E6 neurotoxin differed 3 to 6% from the other subtypes, suggesting that these subtype E6 neurotoxins may possess specific antigenic or functional properties.Clostridium botulinum strains produce one or two of the lethal botulinum neurotoxins (BoNTs) designated A to G according to antigenic properties. These toxins are produced as a progenitor complex consisting of BoNT, hemagglutinin (HA), nontoxic non-HA (NTNH), and probably other uncharacterized components, such as P47 and OrfX (14, 15). The genes encoding these proteins are linked as a cluster and vary in composition and structure among different serotypes and strains. In general, the ntnh and bont genes are located conjointly and arranged in the downstream region of the gene cluster, whereas the upstream regions vary between different types and subtypes of C. botulinum (15).C. botulinum type E predominates in aquatic environments. It differs from the terrestrial toxinotypes of C. botulinum in the arrangement of the neurotoxin gene cluster. Kubota et al. showed that in C. botulinum strain Iwanai, the orfx2, orfx1, and p47 genes are arranged sequentially in the upstream region of the type E neurotoxin gene cluster (19). The partial orfx2 (676 bp) was found in the distal upstream region in the same orientation as orfx1, whereas p47 was located immediately upstream of ntnh and had the opposite orientation to orfx2 and orfx1. The type E neurotoxin-producing Clostridium butyricum strain BL6340 was further shown to be identical to C. botulinum Iwanai in toxin gene arrangement (19). To date, no more sequences of type E neurotoxin gene clusters are available, and the sequences of the complete orfx2 gene and the further upstream region of orfx2 in type E strains are unknown. Type A2 and F strains have orfx2, orfx1, and p47 genes similar to those of type E but with a regulator gene, botR, located ...

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Genetic Analysis of Type E Botulinum Toxin-Producing Clostridium butyricum Strains

Cited by 63 publications

References 14 publications

Targeting lentiviral vectors to specific cell types in vivo

Targeting lentiviral vectors to specific cell types in vivo

37-kDa Laminin Receptor Precursor Modulates Cytotoxic Necrotizing Factor 1–mediated RhoA Activation and Bacterial Uptake

Sequencing the Botulinum Neurotoxin Gene and Related Genes in Clostridium botulinum Type E Strains Reveals orfx3 and a Novel Type E Neurotoxin Subtype

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