Ribosome-associated vesicles: A dynamic subcompartment of the endoplasmic reticulum in secretory cells

The endoplasmic reticulum (ER) is a highly dynamic network of membranes. Here, we combine live-cell microscopy with in situ cryo–electron tomography to directly visualize ER dynamics in several secretory cell types including pancreatic β-cells and neurons under near-native conditions. Using these imaging approaches, we identify a novel, mobile form of ER, ribosome-associated vesicles (RAVs), found primarily in the cell periphery, which is conserved across different cell types and species. We show that RAVs exist as distinct, highly dynamic structures separate from the intact ER reticular architecture that interact with mitochondria via direct intermembrane contacts. These findings describe a new ER subcompartment within cells

Ribosome-associated Vesicles: A Dynamic Subcompartment of the Endoplasmic Reticulum in Secretory Cells

The endoplasmic reticulum (ER) is a highly dynamic network of membranes. Here, we combine live-cell microscopy with in situ cryo-electron tomography to directly visualize ER dynamics in several secretory cell types including pancreatic β-cells and neurons under near-native conditions. Using these imaging approaches, we identify a novel, mobile form of ER, ribosome-associated vesicles (RAVs), found primarily in the cell periphery, which is conserved across different cell types and species. We show that RAVs exist as distinct, highly dynamic structures separate from the intact ER reticular architecture that interact with mitochondria via direct intermembrane contacts. These findings describe a new ER subcompartment within cells.Support for this study was provided by the L. V. Gerstner Jr., Scholars Program (to Z.F.), the Leon Levy Foundation (to Z.F.), the John F. and Nancy A. Emmerling Fund of the Pittsburgh Foundation (to Z.F.), the Department of Defense PR141292 (to Z.F.), NIH K08DA031241 (to Z.F.), NSF MCB-1408986 (to S.A.M.), the National Science Foundation Graduate Research Fellowship (to N.H.T.), NIH K01AG045335 (to E.A.G.), NIH 1S10RR019003 (to S.C.W.), NIH 1S10RR025488 (to S.C.W.), NIH 1S10RR016236 (to S.C.W.), NIH F30NS093798 (to S.E.S.), NIH R56AG058593 (to Z.P.W.), the Howard Hughes Medical Institute (to P.W., N.H.T., J.F., and G.J.J.), NIH GM29169 (to J.F.), NIH GM122588 (to G.J.J.), NIH AI150464 (to G.J.J.), the Israel Science Foundation Grant 1285/14 (to S.G.W.), the European Research Council under the European Union’s Seventh Framework Programme (grant number 310649) (to D.F.), MINECO AIC-A-2011-0638 (to J.M.C.), the Spanish Ministry of Economy and Competitiveness grant BIO2016-76400-R AEI/FEDER, UE (to J.M.C.), and Comunidad Autónoma de Madrid grant S2017/BMD-3817 (to J.M.C.). Some of the cryo-ET was performed in the Beckman Institute Resource Center for Transmission EM at Caltech. Additional work was also performed at the Simons Electron Microscopy Center and National Resource for Automated Molecular Microscopy located at the New York Structural Biology Center, supported by grants from the Simons Foundation (349247), NYSTAR, and the NIH National Institute of General Medical Sciences (GM103310) with added support from NIH S10 RR029300-01. CSTET data acquisition was partially supported by the Irving and Cherna Moskowitz Center for Nano and Bio-Nano Imaging at the Weizmann Institute of Science. Some of the live confocal images were collected and processed in the Confocal and Specialized Microscopy Shared Resource of the Herbert Irving Comprehensive Cancer Center at Columbia University and supported by NIH P30 CA013696. Part of the cryo-EM image processing was conducted as an Instruct-ERIC collaboration project PD1222 at the Instruct Image Processing CenterPeer reviewe

Ribosome-associated vesicles: A dynamic subcompartment of the endoplasmic reticulum in secretory cells.

The endoplasmic reticulum (ER) is a highly dynamic network of membranes. Here, we combine live-cell microscopy with in situ cryo-electron tomography to directly visualize ER dynamics in several secretory cell types including pancreatic β-cells and neurons under near-native conditions. Using these imaging approaches, we identify a novel, mobile form of ER, ribosome-associated vesicles (RAVs), found primarily in the cell periphery, which is conserved across different cell types and species. We show that RAVs exist as distinct, highly dynamic structures separate from the intact ER reticular architecture that interact with mitochondria via direct intermembrane contacts. These findings describe a new ER subcompartment within cells