Blog
About

31
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Specific targeting of proteins to outer envelope membranes of endosymbiotic organelles, chloroplasts, and mitochondria

      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

          Chloroplasts and mitochondria are endosymbiotic organelles thought to be derived from endosymbiotic bacteria. In present-day eukaryotic cells, these two organelles play pivotal roles in photosynthesis and ATP production. In addition to these major activities, numerous reactions, and cellular processes that are crucial for normal cellular functions occur in chloroplasts and mitochondria. To function properly, these organelles constantly communicate with the surrounding cellular compartments. This communication includes the import of proteins, the exchange of metabolites and ions, and interactions with other organelles, all of which heavily depend on membrane proteins localized to the outer envelope membranes. Therefore, correct and efficient targeting of these membrane proteins, which are encoded by the nuclear genome and translated in the cytosol, is critically important for organellar function. In this review, we summarize the current knowledge of the mechanisms of protein targeting to the outer membranes of mitochondria and chloroplasts in two different directions, as well as targeting signals and cytosolic factors.

          Related collections

          Most cited references 86

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

          Importing mitochondrial proteins: machineries and mechanisms.

          Most mitochondrial proteins are synthesized on cytosolic ribosomes and must be imported across one or both mitochondrial membranes. There is an amazingly versatile set of machineries and mechanisms, and at least four different pathways, for the importing and sorting of mitochondrial precursor proteins. The translocases that catalyze these processes are highly dynamic machines driven by the membrane potential, ATP, or redox reactions, and they cooperate with molecular chaperones and assembly complexes to direct mitochondrial proteins to their correct destinations. Here, we discuss recent insights into the importing and sorting of mitochondrial proteins and their contributions to mitochondrial biogenesis.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Translocation of proteins into mitochondria.

            About 10% to 15% of the nuclear genes of eukaryotic organisms encode mitochondrial proteins. These proteins are synthesized in the cytosol and recognized by receptors on the surface of mitochondria. Translocases in the outer and inner membrane of mitochondria mediate the import and intramitochondrial sorting of these proteins; ATP and the membrane potential are used as energy sources. Chaperones and auxiliary factors assist in the folding and assembly of mitochondrial proteins into their native, three-dimensional structures. This review summarizes the present knowledge on the import and sorting of mitochondrial precursor proteins, with a special emphasis on unresolved questions and topics of current research.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Comprehensive characterization of genes required for protein folding in the endoplasmic reticulum.

              Protein folding in the endoplasmic reticulum is a complex process whose malfunction is implicated in disease and aging. By using the cell's endogenous sensor (the unfolded protein response), we identified several hundred yeast genes with roles in endoplasmic reticulum folding and systematically characterized their functional interdependencies by measuring unfolded protein response levels in double mutants. This strategy revealed multiple conserved factors critical for endoplasmic reticulum folding, including an intimate dependence on the later secretory pathway, a previously uncharacterized six-protein transmembrane complex, and a co-chaperone complex that delivers tail-anchored proteins to their membrane insertion machinery. The use of a quantitative reporter in a comprehensive screen followed by systematic analysis of genetic dependencies should be broadly applicable to functional dissection of complex cellular processes from yeast to human.
                Bookmark

                Author and article information

                Contributors
                Journal
                Front Plant Sci
                Front Plant Sci
                Front. Plant Sci.
                Frontiers in Plant Science
                Frontiers Media S.A.
                1664-462X
                29 April 2014
                2014
                : 5
                Affiliations
                1Cellular Systems Biology, Department of Life Sciences, Pohang University of Science and Technology Pohang, South Korea
                2Division of Integrative Biosciences and Bioengineering, Pohang University of Science and Technology Pohang, South Korea
                Author notes

                Edited by: Kentaro Inoue, University of California at Davis, USA

                Reviewed by: Ben Matthew Abell, Sheffield Hallam University, UK; Hsou-min Li, Academia Sinica, Taiwan

                *Correspondence: Inhwan Hwang, Cellular Systems Biology, Department of Life Sciences and Division of Integrative Biosciences and Bioengineering, Pohang University of Science and Technology, Hyojadong, Nam-Gu, Pohang 790-784, South Korea e-mail: ihhwang@ 123456postech.ac.kr

                Junho Lee and Dae Heon Kim contributed equally to this work.

                This article was submitted to Plant Cell Biology, a section of the journal Frontiers in Plant Science.

                Article
                10.3389/fpls.2014.00173
                4010795
                24808904
                Copyright © 2014 Lee, Kim and Hwang.

                This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

                Counts
                Figures: 3, Tables: 1, Equations: 0, References: 86, Pages: 11, Words: 0
                Categories
                Plant Science
                Review Article

                Comments

                Comment on this article