Dataset Information

Lipid reorganization induced by Shiga toxin clustering on planar membranes.

ABSTRACT: The homopentameric B-subunit of bacterial protein Shiga toxin (STxB) binds to the glycolipid Gb(3) in plasma membranes, which is the initial step for entering cells by a clathrin-independent mechanism. It has been suggested that protein clustering and lipid reorganization determine toxin uptake into cells. Here, we elucidated the molecular requirements for STxB induced Gb(3) clustering and for the proposed lipid reorganization in planar membranes. The influence of binding site III of the B-subunit as well as the Gb(3) lipid structure was investigated by means of high resolution methods such as fluorescence and scanning force microscopy. STxB was found to form protein clusters on homogenous 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/cholesterol/Gb(3) (65:30:5) bilayers. In contrast, membranes composed of DOPC/cholesterol/sphingomyelin/Gb(3) (40:35:20:5) phase separate into a liquid ordered and liquid disordered phase. Dependent on the fatty acid composition of Gb(3), STxB-Gb(3) complexes organize within the liquid ordered phase upon protein binding. Our findings suggest that STxB is capable of forming a new membrane phase that is characterized by lipid compaction. The significance of this finding is discussed in the context of Shiga toxin-induced formation of endocytic membrane invaginations.

SUBMITTER: Windschiegl B

PROVIDER: S-EPMC2705791 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Lipid reorganization induced by Shiga toxin clustering on planar membranes.

Windschiegl Barbara B Orth Alexander A Römer Winfried W Berland Ludwig L Stechmann Bahne B Bassereau Patricia P Johannes Ludger L Steinem Claudia C

PloS one 20090716 7

The homopentameric B-subunit of bacterial protein Shiga toxin (STxB) binds to the glycolipid Gb(3) in plasma membranes, which is the initial step for entering cells by a clathrin-independent mechanism. It has been suggested that protein clustering and lipid reorganization determine toxin uptake into cells. Here, we elucidated the molecular requirements for STxB induced Gb(3) clustering and for the proposed lipid reorganization in planar membranes. The influence of binding site III of the B-subun ...[more]

PMID: 19606209

Similar Datasets

Project description:Shiga toxin (Stx), encoded by stx genes located in prophage sequences, is the major agent responsible for the pathogenicity of Shiga toxin-producing Escherichia coli (STEC) and is closely associated with the development of hemolytic uremic syndrome (HUS). Although numerous Stx prophage sequences have been reported as part of STEC bacterial genomes, the information about the genomic characterization of Stx-converting bacteriophages induced from STEC strains is relatively scarce. The objectives of this study were to genomically characterize two Stx-converting phages induced from environmental STEC strains and to evaluate their correlations with published Stx-converting phages and STEC strains of different origins. The Stx1-converting phage Lys8385Vzw and the Stx2-converting phage Lys19259Vzw were induced from E. coli O103:H11 (RM8385) and E. coli O157:H7 (RM19259), respectively. Whole-genome sequencing of these phages was conducted on a MiSeq sequencer for genomic characterization. Phylogenetic analysis and comparative genomics were performed to determine the correlations between these two Stx-converting phages, 13 reference Stx-converting phages, and 10 reference STEC genomes carrying closely related Stx prophages. Both Stx-converting phages Lys8385Vzw and Lys19259Vzw had double-stranded DNA, with genome sizes of 50,953 and 61,072 bp, respectively. Approximately 40% of the annotated coding DNA sequences with the predicted functions were likely associated with the fitness for both phages and their bacterial hosts. The whole-genome-based phylogenetic analysis of these two Stx-converting phages and 13 reference Stx-converting phages revealed that the 15 Stx-converting phages were divided into three distinct clusters, and those from E. coli O157:H7, in particular, were distributed in each cluster, demonstrating the high genomic diversity of these Stx-converting phages. The genomes of Stx-converting phage Lys8385Vzw and Lys19259Vzw shared a high-nucleotide similarity with the prophage sequences of the selected STEC isolates from the clinical and environmental origin. The findings demonstrate the genomic diversity of Stx-converting phages induced from different STEC strains and provide valuable insights into the dissemination of stx genes among E. coli population via the lysogenization of Stx-converting phages.

Dataset Information

Lipid reorganization induced by Shiga toxin clustering on planar membranes.

Publications

Lipid reorganization induced by Shiga toxin clustering on planar membranes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets