tailieunhanh - Báo cáo khoa học: Assembly and molecular mode of action of the Helicobacter pylori Cag type IV secretion apparatus

Bacterial type IV secretion systems (T4SS) form supramolecular protein complexes that are capable of transporting DNA or protein substrates across the bacterial cell envelope and, in many cases, also across eukaryotic target cell membranes. | IFEBS Journal MINIREVIEW Assembly and molecular mode of action of the Helicobacter pylori Cag type IV secretion apparatus Wolfgang Fischer Max von Pettenkofer-Institut Ludwig-Maximilians-Universitat Munchen Germany Keywords CagA Helicobacter pylori pathogenicity island protein translocation secretion apparatus type IV secretion Correspondence W. Fischer Max von Pettenkofer-Institut Ludwig-Maximilians-Universitat Pettenkoferstrasse 9a 80336 Munchen Germany Fax 49 89 51605223 Tel 49 89 51605277 E-mail fischer@ Received 15 November 2010 accepted 10 January 2011 Bacterial type IV secretion systems T4SS form supramolecular protein complexes that are capable of transporting DNA or protein substrates across the bacterial cell envelope and in many cases also across eukaryotic target cell membranes. Because of these characteristics they are often used by pathogenic bacteria for the injection of host cell-modulating virulence factors. One example is the human pathogen Helicobacter pylori which uses the Cag-T4SS to induce a pro-inflammatory response and multiple cytoskeletal and gene regulatory effects in gastric epithelial cells. Work in recent years has shown that the Cag-T4SS exhibits marked differences in relation to other systems both with respect to the composition of its secretion apparatus and the molecular details of its secretion mechanisms. This review describes the molecular properties of the Cag-T4SS and compares these with prototypical systems of this family of protein transporters. doi Introduction Type IV secretion systems T4SS represent a family of macromolecule transporters that is widely distributed in prokaryotes and individual members of this family have adapted to their cellular background and to a variety of substrates as DNA import and export systems conjugation systems or effector protein translocation systems 1 . Several pathogenic bacteria have adopted T4SS for the secretion of virulence-associated