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Domart MC, Hobday TMC, Peddie CJ, Chung GHC, Wang A, Yeh K, Jethwa N, Zhang Q, Wakelam MJO, Woscholski R, Byrne RD, Collinson LM, Poccia DL, Larijani B. Acute manipulation of diacylglycerol reveals roles in nuclear envelope assembly & endoplasmic reticulum morphology. PLoS One 2012; 7:e51150. [PMID: 23227247 PMCID: PMC3515572 DOI: 10.1371/journal.pone.0051150] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/29/2012] [Indexed: 12/16/2022] Open
Abstract
The functions and morphology of cellular membranes are intimately related and depend not only on their protein content but also on the repertoire of lipids that comprise them. In the absence of in vivo data on lipid asymmetry in endomembranes, it has been argued that motors, scaffolding proteins or integral membrane proteins rather than non-lamellar bilayer lipids such as diacylglycerol (DAG), are responsible for shaping of organelles, local membrane curvature and fusion. The effects of direct alteration of levels of such lipids remain predominantly uninvestigated. Diacylglycerol (DAG) is a well documented second messenger. Here we demonstrate two additional conserved functions of DAG: a structural role in organelle morphology, and a role in localised extreme membrane curvature required for fusion for which proteins alone are insufficient. Acute and inducible DAG depletion results in failure of the nuclear envelope (NE) to reform at mitosis and reorganisation of the ER into multi-lamellar sheets as revealed by correlative light and electron microscopy and 3D reconstructions. Remarkably, depleted cells divide without a complete NE, and unless rescued by 1,2 or 1,3 DAG soon die. Attenuation of DAG levels by enzyme microinjection into echinoderm eggs and embryos also results in alterations of ER morphology and nuclear membrane fusion. Our findings demonstrate that DAG is an in vivo modulator of organelle morphology in mammalian and echinoderm cells, indicating a fundamental role conserved across the deuterostome superphylum.
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Affiliation(s)
- Marie-Charlotte Domart
- Cell Biophysics Laboratory, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
| | - Tina M. C. Hobday
- Cell Biophysics Laboratory, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
| | - Christopher J. Peddie
- Electron Microscopy Unit, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
| | - Gary H. C. Chung
- Cell Biophysics Laboratory, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
| | - Alan Wang
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
| | - Karen Yeh
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
| | - Nirmal Jethwa
- Cell Biophysics Laboratory, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
| | - Qifeng Zhang
- The Babraham Institute, Babraham Research Campus, Cambridge, United Kingdom
| | | | - Rudiger Woscholski
- Department of Chemistry, Faculty of Natural Sciences and Institute of Chemical Biology, Imperial College London, London, United Kingdom
| | - Richard D. Byrne
- Cell Biophysics Laboratory, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
| | - Lucy M. Collinson
- Electron Microscopy Unit, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
| | - Dominic L. Poccia
- Department of Biology, Amherst College, Amherst, Massachusetts, United States of America
| | - Banafshé Larijani
- Cell Biophysics Laboratory, London Research Institute, Cancer Research United Kingdom, London, United Kingdom
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