16
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Advances on the Transfer of Lipids by Lipid Transfer Proteins

      review-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Transfer of lipid across the cytoplasm is an essential process for intracellular lipid traffic. Lipid transfer proteins (LTPs) are defined by highly controlled in vitro experiments. The functional relevance of these is supported by evidence for the same reactions inside cells. Major advances in the LTP field have come from structural bioinformatics identifying new LTPs, and from the development of countercurrent models for LTPs. However, the ultimate aim is to unite in vitro and in vivo data, and this is where much progress remains to be made. Even where in vitro and in vivo experiments align, rates of transfer tend not to match. Here we set out some of the advances that might test how LTPs work.

          Trends

          LTPs facilitate the essential movement of lipid across aqueous spaces and are defined by in vitro experiments.

          Recent developments include a novel concept of countercurrent lipid transfer and identification of additional LTP families by bioinformatics.

          In vivo and in vitro data have yet to converge to one complete model.

          Advances in in vitro characterisation of LTPs provide an opportunity to unite biochemical experimentation to cellular function.

          Related collections

          Most cited references110

          • Record: found
          • Abstract: found
          • Article: not found

          An ER-mitochondria tethering complex revealed by a synthetic biology screen.

          Communication between organelles is an important feature of all eukaryotic cells. To uncover components involved in mitochondria/endoplasmic reticulum (ER) junctions, we screened for mutants that could be complemented by a synthetic protein designed to artificially tether the two organelles. We identified the Mmm1/Mdm10/Mdm12/Mdm34 complex as a molecular tether between ER and mitochondria. The tethering complex was composed of proteins resident of both ER and mitochondria. With the use of genome-wide mapping of genetic interactions, we showed that the components of the tethering complex were functionally connected to phospholipid biosynthesis and calcium-signaling genes. In mutant cells, phospholipid biosynthesis was impaired. The tethering complex localized to discrete foci, suggesting that discrete sites of close apposition between ER and mitochondria facilitate interorganelle calcium and phospholipid exchange.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Lipid landscapes and pipelines in membrane homeostasis.

            The lipid composition of cellular organelles is tailored to suit their specialized tasks. A fundamental transition in the lipid landscape divides the secretory pathway in early and late membrane territories, allowing an adaptation from biogenic to barrier functions. Defending the contrasting features of these territories against erosion by vesicular traffic poses a major logistical problem. To this end, cells evolved a network of lipid composition sensors and pipelines along which lipids are moved by non-vesicular mechanisms. We review recent insights into the molecular basis of this regulatory network and consider examples in which malfunction of its components leads to system failure and disease.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              A four-step cycle driven by PI(4)P hydrolysis directs sterol/PI(4)P exchange by the ER-Golgi tether OSBP.

              Several proteins at endoplasmic reticulum (ER)-Golgi membrane contact sites contain a PH domain that interacts with the Golgi phosphoinositide PI(4)P, a FFAT motif that interacts with the ER protein VAP-A, and a lipid transfer domain. This architecture suggests the ability to both tether organelles and transport lipids between them. We show that in oxysterol binding protein (OSBP) these two activities are coupled by a four-step cycle. Membrane tethering by the PH domain and the FFAT motif enables sterol transfer by the lipid transfer domain (ORD), followed by back transfer of PI(4)P by the ORD. Finally, PI(4)P is hydrolyzed in cis by the ER protein Sac1. The energy provided by PI(4)P hydrolysis drives sterol transfer and allows negative feedback when PI(4)P becomes limiting. Other lipid transfer proteins are tethered by the same mechanism. Thus, OSBP-mediated back transfer of PI(4)P might coordinate the transfer of other lipid species at the ER-Golgi interface. Copyright © 2013 Elsevier Inc. All rights reserved.
                Bookmark

                Author and article information

                Contributors
                Journal
                Trends Biochem Sci
                Trends Biochem. Sci
                Trends in Biochemical Sciences
                Elsevier Trends Journals
                0968-0004
                1 July 2017
                July 2017
                : 42
                : 7
                : 516-530
                Affiliations
                [1 ]UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
                [2 ]Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, F‐75013 Paris, France
                Author notes
                [* ]Correspondence: tim.levine@ 123456ucl.ac.uk
                Article
                S0968-0004(17)30089-0
                10.1016/j.tibs.2017.05.001
                5486777
                28579073
                5d097de7-ef2e-4415-93f7-11b527c8b09c
                © 2017 The Authors. Published by Elsevier Ltd.

                This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

                History
                Categories
                Review

                Biochemistry
                lipid exchange,nonvesicular traffic,oxysterol binding protein-related proteins,tubular lipid binding proteins

                Comments

                Comment on this article