Deciphering the molecular architecture of membrane contact sites by cryo-electron tomography.
At membrane contact sites (MCS) two cellular membranes form tight appositions that play critical roles in fundamental phenomena such as lipid metabolism or Ca2+homeostasis. The interest for these structures has surged in recent years, bringing about the characterization of a plethora of MCS-resident molecules. How those molecules are structurally organized at MCS remains enigmatic, limiting our understanding of MCS function. Whereas such molecular detail is obscured by conventional electron microscopy sample preparation, cryo-electron tomography (cryo-ET) allows high resolution imaging of cellular landscapes in close-to-native conditions. Here we briefly review the fundamentals of cryo-ET and how recent developments in this technique are beginning to unveil the molecular architecture of MCS. This article is part of a Special Issue entitled: Membrane Contact Sites edited by Christian Ungermann and Benoit Kornmann.
Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany; Graduate School of Quantitative Biosciences Munich, 81337 Munich, Germany.
Javier
J
Collado
Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany. Electronic address: ruben@biochem.mpg.de.
Rubén
R
Fernández-Busnadiego
D000818:Animals; D020285:Cryoelectron Microscopy / Q000379:methods*; D055032:Electron Microscope Tomography / Q000379:methods*; D006801:Humans; D007425:Intracellular Membranes / Q000648:ultrastructure*; D008561:Membrane Fusion
Cryo-EM; Cryo-focused ion beam milling; Endoplasmic reticulum; Extended synaptotagmin; Membrane tether; Vitrification