DNA Inversion Regulates Outer Membrane Vesicle Production in B<em>acteroides fragilis</em>
2016
Nakayama-Imaohji, Haruyuki | Hirota, Katsuhiko | Yamasaki, Hisashi | Yoneda, Saori | Nariya, Hirofumi | Suzuki, Motoo | Secher, Thomas | Miyake, Yoichiro | Oswald, Eric | Hayashi, Tetsuya | Kuwahara, Tomomi | Department of Microbiology, Faculty of Medicine ; دانشگاه علوم پزشکی و خدمات بهداشتی - درمانی گیلان = Guilan University of Medical Sciences (GUMS) | University of Tokushima ; Tokushima University | Wakayama Medical University = Wakayama Kenritsu Ika Daigaku | Centre de Physiopathologie de Toulouse-Purpan (INSERM U563 - CNRS UMR1037) ; Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Institut Claudius Regaud (ICR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre de lutte contre le cancer (CLCC)-Centre National de la Recherche Scientifique (CNRS) | Service Bactériologie et hygiène [CHU Toulouse] ; Institut Fédératif de Biologie (IFB) ; Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Pôle Biologie [CHU Toulouse] ; Centre Hospitalier Universitaire de Toulouse (CHU Toulouse) | Kyushu University | KAKENHI [15K00822, 26460530]
International audience
اظهر المزيد [+] اقل [-]إنجليزي. Phase changes in Bacteroides fragilis, a member of the human colonic microbiota, mediate variations in a vast array of cell surface molecules, such as capsular polysaccharides and outer membrane proteins through DNA inversion. The results of the present study show that outer membrane vesicle (OMV) formation in this anaerobe is also controlled by DNA inversions at two distantly localized promoters, IVp-I and IVp-II that are associated with extracellular polysaccharide biosynthesis and the expression of outer membrane proteins. These promoter inversions are mediated by a single tyrosine recombinase encoded by BF2766 (orthologous to tsr19 in strain NCTC9343) in B. fragilis YCH46, which is located near IVp-I. A series of BF2766 mutants were constructed in which the two promoters were locked in different configurations (IVp-I/IVp-II = ON/ON, OFF/OFF, ON/OFF or OFF/ON). ON/ON B. fragilis mutants exhibited hypervesiculating, whereas the other mutants formed only a trace amount of OMVs. The hypervesiculating ON/ON mutants showed higher resistance to treatment with bile, LL-37, and human beta-defensin 2. Incubation of wild-type cells with 5% bile increased the population of cells with the ON/ON genotype. These results indicate that B. fragilis regulates the formation of OMVs through DNA inversions at two distantly related promoter regions in response to membrane stress, although the mechanism underlying the interplay between the two regions controlled by the invertible promoters remains unknown.
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل Institut national de la recherche agronomique