In situ imaging of bacterial outer membrane projections and associated protein complexes using electron cryo-tomography

eLife

Yi-Wei Chang¹  Yongtao Zhu²  Mark J McBride³  Morgan Beeby⁴  Lori A Zacharoff⁵  Cecily R Wood⁶  Carrie L Shaffer⁷  Mohammed Kaplan⁸  Yuhang Wang⁸  Lauren Ann Metskas⁸  Catherine M Oikonomou⁸  William J Nicolas⁸  Poorna Subramanian⁸  Georges Chreifi⁸  Grant J Jensen⁹  Megan J Dobro^1,10  Janine Liedtke^1,11  Ariane Briegel^1,11 

[1] Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States;Department of Biological Sciences, Minnesota State University, Mankato, United States;Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, United States;Department of Life Sciences, Imperial College London, London, United Kingdom;Department of Physics and Astronomy, University of Southern California, Los Angeles, United States;Department of Veterinary Science, University of Kentucky, Lexington, United States;Department of Veterinary Science, University of Kentucky, Lexington, United States;Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, United States;Department of Pharmaceutical Sciences, University of Kentucky, Lexington, United States;Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States;Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States;Department of Chemistry and Biochemistry, Brigham Young University, Provo, United States;Hampshire College, Amherst, United States;Leiden University, Sylvius Laboratories, Leiden, Netherlands;

关键词: cryo-ET;    membrane extensions;    tubes;    vesicles;    secretin;    bacteria;    Other;   

DOI  :  10.7554/eLife.73099

来源: eLife Sciences Publications, Ltd

【 摘 要 】

The ability to produce outer membrane projections in the form of tubular membrane extensions (MEs) and membrane vesicles (MVs) is a widespread phenomenon among diderm bacteria. Despite this, our knowledge of the ultrastructure of these extensions and their associated protein complexes remains limited. Here, we surveyed the ultrastructure and formation of MEs and MVs, and their associated protein complexes, in tens of thousands of electron cryo-tomograms of ~90 bacterial species that we have collected for various projects over the past 15 years (Jensen lab database), in addition to data generated in the Briegel lab. We identified outer MEs and MVs in 13 diderm bacterial species and classified several major ultrastructures: (1) tubes with a uniform diameter (with or without an internal scaffold), (2) tubes with irregular diameter, (3) tubes with a vesicular dilation at their tip, (4) pearling tubes, (5) connected chains of vesicles (with or without neck-like connectors), (6) budding vesicles and nanopods. We also identified several protein complexes associated with these MEs and MVs which were distributed either randomly or exclusively at the tip. These complexes include a secretin-like structure and a novel crown-shaped structure observed primarily in vesicles from lysed cells. In total, this work helps to characterize the diversity of bacterial membrane projections and lays the groundwork for future research in this field.

【 授权许可】

CC BY