title: Characterization of interactions between inclusion membrane proteins from Chlamydia trachomatis.
abstract: Chlamydiae are obligate intracellular pathogens of eukaryotes. The bacteria grow in an intracellular vesicle called an inclusion, the membrane of which is heavily modified by chlamydial proteins called Incs (Inclusion membrane proteins). Incs represent 7-10% of the genomes of Chlamydia and, given their localization at the interface between the host and the pathogen, likely play a key role in the development and pathogenesis of the bacterium. However, their functions remain largely unknown. Here, we characterized the interaction properties between various Inc proteins of C. trachomatis, using a bacterial two-hybrid (BACTH) method suitable for detecting interactions between integral membrane proteins. To validate this approach, we first examined the oligomerization properties of the well-characterized IncA protein and showed that both the cytoplasmic domain and the transmembrane region independently contribute to IncA oligomerization. We then analyzed a set of Inc proteins and identified novel interactions between these components. Two small Incs, IncF, and Ct222, were found here to interact with many other Inc proteins and may thus represent interaction nodes within the inclusion membrane. Our data suggest that the Inc proteins may assemble in the membrane of the inclusion to form specific multi-molecular complexes in an hierarchical and temporal manner. These studies will help to better define the putative functions of the Inc proteins in the infectious process of Chlamydia.
authors.affiliation: Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, Institut Pasteur, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3528 Paris, France ; Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur Paris, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Gauliard
authors.affiliation: Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota Vermillion, SD, USA.
authors.forename: Scot P
authors.initials: SP
authors.lastname: Ouellette
authors.affiliation: Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota Vermillion, SD, USA.
authors.forename: Kelsey J
authors.initials: KJ
authors.lastname: Rueden
authors.affiliation: Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, Institut Pasteur, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3528 Paris, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ladant
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002690:Chlamydia Infections / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D020798:Two-Hybrid System Techniques
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins
keywords: BACTH; Chlamydia; Inc protein; bacterial two-hybrid system; inclusion membrane proteins; protein-protein interactions