Gene Symbol: TOC159
Description: translocon at the outer envelope membrane of chloroplasts 159
Alias: ATTOC159, PLASTID PROTEIN IMPORT 2, PPI2, T10P11.19, TOC160, TOC86, TRANSLOCON AT THE OUTER ENVELOPE MEMBRANE OF CHLOROPLASTS 160, TRANSLOCON AT THE OUTER ENVELOPE MEMBRANE OF CHLOROPLASTS 86, translocon at the outer envelope membrane of chloroplasts 159, translocon at the outer envelope membrane of chloroplasts 159
Species: thale cress

Top Publications

  1. Infanger S, Bischof S, Hiltbrunner A, Agne B, Baginsky S, Kessler F. The chloroplast import receptor Toc90 partially restores the accumulation of Toc159 client proteins in the Arabidopsis thaliana ppi2 mutant. Mol Plant. 2011;4:252-63 pubmed publisher
    ..precursor recognition is mainly mediated by outer membrane receptors belonging to two gene families: Toc34/33 and Toc159/132/120/90...
  2. Weibel P, Hiltbrunner A, Brand L, Kessler F. Dimerization of Toc-GTPases at the chloroplast protein import machinery. J Biol Chem. 2003;278:37321-9 pubmed
    Import of chloroplast precursor proteins is controlled by the coordinate action of two homologous GTPases, Toc159 and Toc33, located at the cytosol-outer membrane interface...
  3. Bauer J, Hiltbrunner A, Weibel P, Vidi P, Alvarez Huerta M, Smith M, et al. Essential role of the G-domain in targeting of the protein import receptor atToc159 to the chloroplast outer membrane. J Cell Biol. 2002;159:845-54 pubmed
    Two homologous GTP-binding proteins, atToc33 and atToc159, control access of cytosolic precursor proteins to the chloroplast...
  4. Smith M, Hiltbrunner A, Kessler F, Schnell D. The targeting of the atToc159 preprotein receptor to the chloroplast outer membrane is mediated by its GTPase domain and is regulated by GTP. J Cell Biol. 2002;159:833-43 pubmed, we examined the mechanism of targeting and insertion of the Arabidopsis thaliana orthologue of Toc159, atToc159, to chloroplasts...
  5. Becker T, Jelic M, Vojta A, Radunz A, Soll J, Schleiff E. Preprotein recognition by the Toc complex. EMBO J. 2004;23:520-30 pubmed
    The Toc core complex consists of the pore-forming Toc75 and the GTPases Toc159 and Toc34. We confirm that the receptor form of Toc159 is integrated into the membrane...
  6. Lee D, Lee S, Oh Y, Hwang I. Multiple sequence motifs in the rubisco small subunit transit peptide independently contribute to Toc159-dependent import of proteins into chloroplasts. Plant Physiol. 2009;151:129-41 pubmed publisher the nuclear genome are posttranslationally imported into plastids by at least two distinct mechanisms: the Toc159-dependent and Toc132/Toc120-dependent pathways...
  7. Rahim G, Bischof S, Kessler F, Agne B. In vivo interaction between atToc33 and atToc159 GTP-binding domains demonstrated in a plant split-ubiquitin system. J Exp Bot. 2009;60:257-67 pubmed publisher
    The GTPases atToc33 and atToc159 are pre-protein receptor components of the translocon complex at the outer chloroplast membrane in Arabidopsis...
  8. Agne B, Infanger S, Wang F, Hofstetter V, Rahim G, Martin M, et al. A toc159 import receptor mutant, defective in hydrolysis of GTP, supports preprotein import into chloroplasts. J Biol Chem. 2009;284:8670-9 pubmed publisher
    ..Consequently, the ppi2 mutant lacking atToc159 has a non-photosynthetic albino phenotype...
  9. Bischof S, Baerenfaller K, Wildhaber T, Troesch R, Vidi P, Roschitzki B, et al. Plastid proteome assembly without Toc159: photosynthetic protein import and accumulation of N-acetylated plastid precursor proteins. Plant Cell. 2011;23:3911-28 pubmed publisher
    ..b>Toc159 is thought to be the main receptor for photosynthetic proteins, but lacking a large-scale systems approach, this ..

More Information


  1. Wallas T, Smith M, Sanchez Nieto S, Schnell D. The roles of toc34 and toc75 in targeting the toc159 preprotein receptor to chloroplasts. J Biol Chem. 2003;278:44289-97 pubmed
    ..In the present study, we used the Arabidopsis thaliana orthologs of Toc159 and Toc34, atToc159 and atToc33, respectively, to investigate the requirements for assembly of the trimeric Toc complex...
  2. Oreb M, Höfle A, Mirus O, Schleiff E. Phosphorylation regulates the assembly of chloroplast import machinery. J Exp Bot. 2008;59:2309-16 pubmed publisher
    ..Two receptor components of this complex, Toc34 and Toc159, are GTPases, which can be phosphorylated by kinases present in the hosting membrane...
  3. Smith M, Rounds C, Wang F, Chen K, Afitlhile M, Schnell D. atToc159 is a selective transit peptide receptor for the import of nucleus-encoded chloroplast proteins. J Cell Biol. 2004;165:323-34 pubmed
    The members of the Toc159 family of GTPases act as the primary receptors for the import of nucleus-encoded preproteins into plastids...
  4. Bauer J, Chen K, Hiltbunner A, Wehrli E, Eugster M, Schnell D, et al. The major protein import receptor of plastids is essential for chloroplast biogenesis. Nature. 2000;403:203-7 pubmed
    ..Here we show that Arabidopsis thaliana Toc159 (atToc159) is essential for the biogenesis of chloroplasts...
  5. Richardson L, Jelokhani Niaraki M, Smith M. The acidic domains of the Toc159 chloroplast preprotein receptor family are intrinsically disordered protein domains. BMC Biochem. 2009;10:35 pubmed publisher
    ..Using CD spectroscopy we show that the A-domains of two Arabidopsis Toc159 family members (atToc132 and atToc159) are disordered at physiological pH and temperature and undergo conformational changes at temperature and pH ..
  6. Hernández Torres J, Maldonado M, Chomilier J. Tandem duplications of a degenerated GTP-binding domain at the origin of GTPase receptors Toc159 and thylakoidal SRP. Biochem Biophys Res Commun. 2007;364:325-31 pubmed
    ..In particular, atToc159 and related proteins (atToc132, atToc120, and atToc90) do not have proven homologues of prokaryotic or eukaryotic ..
  7. Wang F, Agne B, Kessler F, Schnell D. The role of GTP binding and hydrolysis at the atToc159 preprotein receptor during protein import into chloroplasts. J Cell Biol. 2008;183:87-99 pubmed publisher
    ..We show that atToc159-A864R, a receptor with reduced GTPase activity, can fully complement a lethal insertion mutation in the ATTOC159 ..
  8. Inoue H, Rounds C, Schnell D. The molecular basis for distinct pathways for protein import into Arabidopsis chloroplasts. Plant Cell. 2010;22:1947-60 pubmed publisher
    ..Furthermore, the in vivo function of the two major Toc159 family members (atToc159 and atToc132) can be largely switched by swapping their A-domains in transgenic Arabidopsis thaliana...
  9. Ling Q, Huang W, Baldwin A, Jarvis P. Chloroplast biogenesis is regulated by direct action of the ubiquitin-proteasome system. Science. 2012;338:655-9 pubmed publisher
    ..Thus, the ubiquitin-proteasome system acts on plastids to control their development. ..
  10. Dutta S, Teresinski H, Smith M. A split-ubiquitin yeast two-hybrid screen to examine the substrate specificity of atToc159 and atToc132, two Arabidopsis chloroplast preprotein import receptors. PLoS ONE. 2014;9:e95026 pubmed publisher
    ..Although there is good evidence that atToc159 and atToc132 from Arabidopsis mediate the initial sorting step, preferentially recognizing photosynthetic and non-..
  11. Inaba T, Alvarez Huerta M, Li M, Bauer J, Ewers C, Kessler F, et al. Arabidopsis tic110 is essential for the assembly and function of the protein import machinery of plastids. Plant Cell. 2005;17:1482-96 pubmed
    ..Together, these data suggest that Tic110 plays a general role in the import of nuclear-encoded preproteins as a common component of Tic complexes. ..
  12. Agne B, Andres C, Montandon C, Christ B, Ertan A, Jung F, et al. The acidic A-domain of Arabidopsis TOC159 occurs as a hyperphosphorylated protein. Plant Physiol. 2010;153:1016-30 pubmed publisher
    ..The preprotein receptors Toc159 and Toc33 in Arabidopsis (Arabidopsis thaliana) are specific for the accumulation of abundant photosynthetic ..
  13. Kim D, Park M, Gwon G, Silkov A, Xu Z, Yang E, et al. An ankyrin repeat domain of AKR2 drives chloroplast targeting through coincident binding of two chloroplast lipids. Dev Cell. 2014;30:598-609 pubmed publisher
  14. Koenig P, Oreb M, Rippe K, Muhle Goll C, Sinning I, Schleiff E, et al. On the significance of Toc-GTPase homodimers. J Biol Chem. 2008;283:23104-12 pubmed publisher which an additional factor activates the GTPase in homodimeric form; and 2) the switch hypothesis, in which a protein, presumably the large Toc159 GTPase, exchanges with one of the homodimeric subunits, leading to activation.
  15. Chang J, Chen L, Yeh Y, Hsiao C, Li H. Chloroplast Preproteins Bind to the Dimer Interface of the Toc159 Receptor during Import. Plant Physiol. 2017;173:2148-2162 pubmed publisher
    ..b>Toc159 functions as a primary receptor and directly binds preproteins through its dimeric GTPase domain...
  16. Afitlhile M, Workman S, Duffield K, Sprout D, Berhow M. A mutant of the Arabidopsis thaliana TOC159 gene accumulates reduced levels of linolenic acid and monogalactosyldiacylglycerol. Plant Physiol Biochem. 2013;73:344-50 pubmed publisher
    ..The mutant is referred as plastid protein import 2 or ppi2 and has an albino phenotype due to its inability to import the photosynthetic proteins...
  17. Agne B, Kessler F. Modifications at the A-domain of the chloroplast import receptor Toc159. Plant Signal Behav. 2010;5:1513-6 pubmed publisher
    Two families of GTPases, the Toc34 and Toc159 GTPase families, take on the task of preprotein recognition at the translocon at the outer membrane of chloroplasts (TOC translocon)...
  18. Chen L, Li H. Stable megadalton TOC-TIC supercomplexes as major mediators of protein import into chloroplasts. Plant J. 2017;92:178-188 pubmed publisher
    ..Two-dimensional BN-PAGE immunoblots further showed that Toc75, Toc159, Toc34, Tic20, Tic56 and Tic110 were all located in the 880-kD to 1.3-MD region...
  19. Hust B, Gutensohn M. Deletion of core components of the plastid protein import machinery causes differential arrest of embryo development in Arabidopsis thaliana. Plant Biol (Stuttg). 2006;8:18-30 pubmed
    ..In contrast, despite the complete or almost complete lack of the import receptors Toc34 and Toc159, embryo development in the a tToc33/34 and atToc132/159 mutants proceeded slowly and was arrested later at the ..
  20. Aronsson H, Jarvis P. Dimerization of TOC receptor GTPases and its implementation for the control of protein import into chloroplasts. Biochem J. 2011;436:e1-2 pubmed publisher
    ..of the TOC (translocon at the outer envelope membrane of chloroplasts) complex are the receptor proteins Toc33 and Toc159. These two receptors are related GTPases, and they are predicted to engage in homodimerization and/or ..
  21. Miras S, Salvi D, Piette L, Seigneurin Berny D, Grunwald D, Reinbothe C, et al. Toc159- and Toc75-independent import of a transit sequence-less precursor into the inner envelope of chloroplasts. J Biol Chem. 2007;282:29482-92 pubmed
    ..experiments, revealed that ceQORH import does not involve the main receptor and translocation channel proteins Toc159 and Toc75, respectively, which operate in import of proteins into the chloroplast...
  22. Reddick L, Vaughn M, Wright S, Campbell I, Bruce B. In vitro comparative kinetic analysis of the chloroplast Toc GTPases. J Biol Chem. 2007;282:11410-26 pubmed
    ..characterization of four Toc GTPases (cytosolic domains of atToc33, atToc34, psToc34, and the GTPase domain of atToc159) to permit their direct comparison...
  23. Wang P, Xue L, Batelli G, Lee S, Hou Y, Van Oosten M, et al. Quantitative phosphoproteomics identifies SnRK2 protein kinase substrates and reveals the effectors of abscisic acid action. Proc Natl Acad Sci U S A. 2013;110:11205-10 pubmed publisher
    ..These results shed new light on the role of the SnRK2 protein kinases and on the downstream effectors of ABA action, and improve our understanding of plant responses to adverse environments. ..
  24. Zhan G, Li R, Hu Z, Liu J, Deng L, Lu S, et al. Cosuppression of RBCS3B in Arabidopsis leads to severe photoinhibition caused by ROS accumulation. Plant Cell Rep. 2014;33:1091-108 pubmed publisher
    ..We found that photoinhibition was due to accumulation of ROS, which accelerated photodamage of PSII and inhibited the repair of PSII in RBCS3B-7. ..
  25. Lee J, Wang F, Schnell D. Toc receptor dimerization participates in the initiation of membrane translocation during protein import into chloroplasts. J Biol Chem. 2009;284:31130-41 pubmed publisher
    ..the transit peptide of preproteins by the coordinate activities of two homologous GTPase Toc receptors, Toc34 and Toc159. Structural and biochemical studies suggest that dimerization of the Toc receptors functions as a component of the ..
  26. Kim C, Ham H, Apel K. Multiplicity of different cell- and organ-specific import routes for the NADPH-protochlorophyllide oxidoreductases A and B in plastids of Arabidopsis seedlings. Plant J. 2005;42:329-40 pubmed
    ..mutants ppi3, ppi1 and ppi2 that are deficient in atToc34, atToc33, a closely related isoform of atToc34, and atToc159. Whereas none of these three Toc constituents is required for maintaining the organ specificity and substrate ..