1
|
Raimondi A, Ilacqua N, Pellegrini L. Liver inter-organelle membrane contact sites revealed by serial section electron tomography. Methods Cell Biol 2023; 177:101-123. [PMID: 37451764 DOI: 10.1016/bs.mcb.2022.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Inter-organelle membrane contact sites (MCSs) are defined as areas of close proximity between the membranes of two organelles (10-80nm). They have been implicated in many physiological processes such as Ca++, lipids or small molecules transfer, organelles biogenesis or dynamic and have an important role in many cellular processes such as apoptosis, autophagy, and signaling. Since the distance and the extent of these contacts are in the nanometer range, high resolution techniques are ideal for imaging these structures. It is for this reason that transmission electron microscopy (TEM) has been considered the gold standard for MCSs visualization and the first technique that described them. However, often TEM analysis is limited to 2D lacking information on the 3D association between the organelles involved in MCSs. To fully describe the complex architecture of MSCs and to unveil their role in cellular physiology a 3D analysis is required. This chapter provides a method for the analysis of MCSs using serial section electron tomography (ssET), a technique able to reconstruct in 3D at nanometer resolution cellular and subcellular structures. By applying this procedure, it was possible to elucidate the role of the contacts between Endoplasmic Reticulum (ER) and other organelles in liver lipid metabolism.
Collapse
Affiliation(s)
- Andrea Raimondi
- Experimental Imaging Centre, IRCCS San Raffaele Scientific Institute, Milan, Italy.
| | - Nicolò Ilacqua
- Mitochondria Biology Laboratory, Brain Research Center, Quebec, QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, QC, Canada
| | - Luca Pellegrini
- Mitochondria Biology Laboratory, Brain Research Center, Quebec, QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, QC, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.
| |
Collapse
|
2
|
Kaplan M, Nicolas WJ, Zhao W, Carter SD, Metskas LA, Chreifi G, Ghosal D, Jensen GJ. In Situ Imaging and Structure Determination of Biomolecular Complexes Using Electron Cryo-Tomography. Methods Mol Biol 2021; 2215:83-111. [PMID: 33368000 DOI: 10.1007/978-1-0716-0966-8_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Electron cryo-tomography (cryo-ET) is a technique that allows the investigation of intact macromolecular complexes while they are in their cellular milieu. Over the years, cryo-ET has had a huge impact on our understanding of how large biomolecular complexes look like, how they assemble, disassemble, function, and evolve(d). Recent hardware and software developments and combining cryo-ET with other techniques, e.g., focused ion beam milling (FIB-milling) and cryo-light microscopy, has extended the realm of cryo-ET to include transient molecular complexes embedded deep in thick samples (like eukaryotic cells) and enhanced the resolution of structures obtained by cryo-ET. In this chapter, we will present an outline of how to perform cryo-ET studies on a wide variety of biological samples including prokaryotic and eukaryotic cells and biological plant tissues. This outline will include sample preparation, data collection, and data processing as well as hybrid approaches like FIB-milling, cryosectioning, and cryo-correlated light and electron microscopy (cryo-CLEM).
Collapse
Affiliation(s)
- Mohammed Kaplan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - William J Nicolas
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Wei Zhao
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Stephen D Carter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Lauren Ann Metskas
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Georges Chreifi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Debnath Ghosal
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Biochemistry and Molecular Biology; and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, USA
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA.
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA.
| |
Collapse
|