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PMID: 10781107 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't

Toc34 is a preprotein receptor regulated by GTP and phosphorylation.

Proceedings of the National Academy of Sciences of the United States of America ·Vol. 97 ·No. 9 ·2000-04-25 ·Pages 4973-8

Sveshnikova N, Soll J, Schleiff E

Abstract

Most proteins present in chloroplasts are synthesized in the cytosol and are posttranslationally translocated into the organelle. A multicomponent translocation machinery located in both the outer and the inner envelope of chloroplasts was identified, but the mode of action of many subunits remains unclear. Here, we describe the regulation of an early step of translocation occurring at the outer envelope. The outer envelope translocon subunit Toc34 can be phosphorylated, and GTP binding is regulated by phosphorylation. In vitro, Toc34 acts as a receptor for proteins containing a chloroplast-targeting signal. Interaction of Toc34 with the transit peptide is highly regulated and depends on GTP binding to Toc34 and on phosphorylation of the transit peptide of the preprotein.

MeSH Terms
Chloroplasts/metabolism Cytosol/metabolism Guanosine Triphosphate/metabolism Intracellular Membranes/metabolism Kinetics Membrane Proteins/metabolism Peas Phosphorylation Plant Proteins/metabolism Protein Processing, Post-Translational Recombinant Proteins/metabolism Superoxide Dismutase/metabolism
Chemicals
Membrane Proteins Plant Proteins Recombinant Proteins Toc34 protein, plant Guanosine Triphosphate Superoxide Dismutase
Authors & Affiliations
3 authors, click to expand affiliations / ORCID
Sveshnikova N
Botanisches Institut, Universität Kiel, 24118 Kiel, Germany.
Soll J
Schleiff E
References (30)
30 references, click to expand
  1. The binding of precursor proteins to chloroplasts requires nucleoside triphosphates in the intermembrane space.
    J Biol Chem. 1992 Jan 5;267(1):433-9 PMID: 1730608
  2. RGS proteins: more than just GAPs for heterotrimeric G proteins.
    Trends Cell Biol. 1999 Apr;9(4):138-44 PMID: 10203790
  3. ATP is required for the binding of precursor proteins to chloroplasts.
    J Biol Chem. 1989 Apr 25;264(12):6724-9 PMID: 2708339
  4. Peptide mapping by limited proteolysis in sodium dodecyl sulfate and analysis by gel electrophoresis.
    J Biol Chem. 1977 Feb 10;252(3):1102-6 PMID: 320200
  5. Protein import into mitochondria.
    Annu Rev Biochem. 1997;66:863-917 PMID: 9242927
  6. Regulation of chloroplast membrane function: protein phosphorylation changes the spatial organization of membrane components.
    J Cell Biol. 1983 Nov;97(5 Pt 1):1327-37 PMID: 6355117
  7. A protein import receptor in pea chloroplasts, Toc86, is only a proteolytic fragment of a larger polypeptide.
    FEBS Lett. 1998 Dec 11;441(1):59-62 PMID: 9877165
  8. A consensus nomenclature for the protein-import components of the chloroplast envelope.
    Trends Cell Biol. 1997 Aug;7(8):303-4 PMID: 17708964
  9. Signal perception and transduction: the role of protein kinases.
    Biochim Biophys Acta. 1999 Feb 4;1449(1):1-24 PMID: 10076047
  10. A receptor component of the chloroplast protein translocation machinery.
    Science. 1994 Dec 23;266(5193):1989-92 PMID: 7801125
  11. Separation of purine 3',5'-cyclic nucleotides and nucleosides by thin-layer chromatography on PEI cellulose.
    J Chromatogr. 1976 Jan 21;116(2):465-7 PMID: 173734
  12. Functional and structural properties of the mitochondrial outer membrane receptor Tom20.
    Biochemistry. 1998 Sep 22;37(38):13043-51 PMID: 9748309
  13. The major protein import receptor of plastids is essential for chloroplast biogenesis.
    Nature. 2000 Jan 13;403(6766):203-7 PMID: 10646606
  14. A constituent of the chloroplast import complex represents a new type of GTP-binding protein.
    Plant J. 1995 Mar;7(3):401-11 PMID: 7757113
  15. Insertion of the 34-kDa chloroplast protein import component, IAP34, into the chloroplast outer membrane is dependent on its intrinsic GTP-binding capacity.
    J Biol Chem. 1997 Mar 7;272(10):6614-20 PMID: 9045691
  16. The GTPase superfamily: conserved structure and molecular mechanism.
    Nature. 1991 Jan 10;349(6305):117-27 PMID: 1898771
  17. Energy dependence of protein translocation into chloroplasts.
    Eur J Biochem. 1986 Nov 3;160(3):563-70 PMID: 3780721
  18. Some general aspects regarding the interpretation of binding data by means of a Scratchard plot.
    Biophys Struct Mech. 1976 Apr 15;2(1):1-12 PMID: 963225
  19. Identification of two GTP-binding proteins in the chloroplast protein import machinery.
    Science. 1994 Nov 11;266(5187):1035-9 PMID: 7973656
  20. Protein import into chloroplasts.
    Curr Opin Plant Biol. 1999 Dec;2(6):471-6 PMID: 10607655
  21. A guanosine 5'-triphosphate-dependent protein kinase is localized in the outer envelope membrane of pea chloroplasts.
    Planta. 1988 Dec;176(4):488-96 PMID: 24220945
  22. Labeling of adenine and guanine nucleotide-binding proteins in permeabilized cells with in situ periodate-oxidized nucleotides.
    Anal Biochem. 1993 Apr;210(1):77-85 PMID: 8387733
  23. Common principles of protein translocation across membranes.
    Science. 1996 Mar 15;271(5255):1519-26 PMID: 8599107
  24. Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts.
    Eur J Biochem. 1988 Aug 1;175(2):301-7 PMID: 3402457
  25. Regulation of cytosolic enzymes in primary metabolism by reversible protein phosphorylation.
    Curr Opin Plant Biol. 1998 Jun;1(3):224-9 PMID: 10066593
  26. Analysis of the interactions of preproteins with the import machinery over the course of protein import into chloroplasts.
    J Cell Biol. 1997 Dec 29;139(7):1677-85 PMID: 9412463
  27. Phosphorylation of the transit sequence of chloroplast precursor proteins.
    J Biol Chem. 1996 Mar 15;271(11):6545-54 PMID: 8626459
  28. GTPase-activating proteins: helping hands to complement an active site.
    Trends Biochem Sci. 1998 Jul;23(7):257-62 PMID: 9697416
  29. Chloroplast phosphoproteins. Evidence for a thylakoid-bound phosphoprotein phosphatase.
    Eur J Biochem. 1980 Feb;104(1):85-9 PMID: 6245872
  30. GTP promotes the formation of early-import intermediates but is not required during the translocation step of protein import into chloroplasts.
    Plant Physiol. 1999 Sep;121(1):237-44 PMID: 10482679
Article Info
Journal
Proceedings of the National Academy of Sciences of the United States of America
Abbr.
Proc Natl Acad Sci U S A
ISSN
0027-8424
DOI
10.1073/pnas.080491597
Published
2000-04-25
Pages
4973-8
Language
English
Region
United States
NLM ID
7505876
PMCID
PMC18342
Subset
IM
External Links
PubMed source DOI: 10.1073/pnas.080491597 PMC Full Text View journal details
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