Advertisement

Plant Molecular Biology

, 77:381 | Cite as

The localization of Tic20 proteins in Arabidopsis thaliana is not restricted to the inner envelope membrane of chloroplasts

  • Anu B. Machettira
  • Lucia E. Gross
  • Maik S. Sommer
  • Benjamin L. Weis
  • Gisela Englich
  • Joanna TrippEmail author
  • Enrico SchleiffEmail author
Article

Abstract

Tic20 is a central, membrane-embedded component of the precursor protein translocon of the inner envelope of chloroplasts (TIC). In Arabidopsis thaliana, four different isoforms of Tic20 exist. They are annotated as atTic20-I, -II, -IV and -V and form two distinct phylogenetic subfamilies in embryophyta. Consistent with atTic20-I being the only essential isoform for chloroplast development, we show that the protein is exclusively targeted to the chloroplasts inner envelope. The same result is observed for atTic20-II. In contrast, atTic20-V is localized in thylakoids and atTic20-IV dually localizes to chloroplasts and mitochondria. These results together with the previously established expression profiles explain the recently described phenotypes of Tic20 knockout plants and point towards a functional diversification of these proteins within the family. For all Tic20 proteins a 4-helix topology is proposed irrespective of the targeted membrane, which in part could be confirmed in vivo by application of a self-assembling GFP-based topology approach. By the same approach we show that the inner envelope localized Tic20 proteins expose their C-termini to the chloroplast stroma. This localization would be consistent with the positive inside rule considering a stromal translocation intermediate as discussed.

Keywords

Tic20 Chloroplast protein import Membrane protein topology 

Notes

Acknowledgments

The work was supported by grants from Deutsche Forschungsgemeinschaft (SFB807-P17), the Center of Membrane Proteomics Frankfurt (CMP), the Cluster of Excellence “Macromolecular Complexes” and Volkswagenstiftung to E.S. and from the Deutsche Forschungsgemeinschaft (TR985/1-1) to J.T. The authors would like to thank Oliver Mirus for bioinformatic support.

References

  1. Bionda T, Tillmann B, Simm S, Beilstein K, Ruprecht M, Schleiff E (2010) Chloroplast import signals: the length requirement for translocation in vitro and in vivo. J Mol Biol 402:510–523PubMedCrossRefGoogle Scholar
  2. Bullmann L, Haarmann R, Mirus O, Bredemeier R, Hempel F, Maier UG, Schleiff E (2010) Filling the gap, evolutionarily conserved Omp85 in plastids of chromalveolates. J Biol Chem 285:6848–6856PubMedCrossRefGoogle Scholar
  3. Cabantous S, Terwilliger TC, Waldo GS (2005) Protein tagging and detection with engineered self-assembling fragments of green fluorescent protein. Nat Biotechnol 23:102–107PubMedCrossRefGoogle Scholar
  4. Chen X, Smith MD, Fitzpatrick L, Schnell DJ (2002) In vivo analysis of the role of atTic20 in protein import into chloroplasts. Plant Cell 14:641–654PubMedCrossRefGoogle Scholar
  5. Emanuelsson O, Nielsen H, Brunak S, von Heijne G (2000) Predicting subcellular localization of proteins based on their N-terminal amino acid sequence. J Mol Biol 300:1005–1016PubMedCrossRefGoogle Scholar
  6. Friso G, Giacomelli L, Ytterberg AJ, Peltier JB, Rudella A, Sun Q, Wijk KJ (2004) In-depth analysis of the thylakoid membrane proteome of Arabidopsis thaliana chloroplasts: new proteins, new functions, and a plastid proteome database. Plant Cell 16:478–499PubMedCrossRefGoogle Scholar
  7. Heins L, Mehrle A, Hemmler R, Wagner R, Kuchler M, Hormann F, Sveshnikov D, Soll J (2002) The preprotein conducting channel at the inner envelope membrane of plastids. EMBO J 21:2616–2625PubMedCrossRefGoogle Scholar
  8. Hirabayashi Y, Kikuchi S, Oishi M, Nakai M (2011) In vivo studies on the roles of two closely related Arabidopsis Tic20 proteins, AtTic20-I and AtTic20-IV. Plant Cell PhysiolGoogle Scholar
  9. Inaba T, Alvarez-Huerta M, Li M, Bauer J, Ewers C, Kessler F, Schnell DJ (2005) Arabidopsis tic110 is essential for the assembly and function of the protein import machinery of plastids. Plant Cell 17:1482–1496PubMedCrossRefGoogle Scholar
  10. Kalanon M, McFadden GI (2008) The chloroplast protein translocation complexes of Chlamydomonas reinhardtii: a bioinformatic comparison of Toc and Tic components in plants, green algae and red algae. Genetics 179:95–112PubMedCrossRefGoogle Scholar
  11. Kasmati AR, Topel M, Patel R, Murtaza G, Jarvis P (2011) Molecular and genetic analyses of Tic20 homologues in Arabidopsis thaliana chloroplasts. Plant J 66:877–889PubMedCrossRefGoogle Scholar
  12. Katoh K, Toh H (2008) Recent developments in the MAFFT multiple sequence alignment program. Brief Bioinf 9:286–298CrossRefGoogle Scholar
  13. Kessler F, Schnell D (2009) Chloroplast biogenesis: diversity and regulation of the protein import apparatus. Curr Opin Cell Biol 21:494–500PubMedCrossRefGoogle Scholar
  14. Kikuchi S, Oishi M, Hirabayashi Y, Lee DW, Hwang I, Nakai M (2009) A 1-megadalton translocation complex containing Tic20 and Tic21 mediates chloroplast protein import at the inner envelope membrane. Plant Cell 21:1781–1797PubMedCrossRefGoogle Scholar
  15. Kleffmann T, Russenberger D, von Zychlinski A, Christopher W, Sjolander K, Gruissem W, Baginsky S (2004) The Arabidopsis thaliana chloroplast proteome reveals pathway abundance and novel protein functions. Curr Biol 14:354–362PubMedCrossRefGoogle Scholar
  16. Kobayashi K, Nakamura Y, Ohta H (2009) Type A and type B monogalactosyldiacylglycerol synthases are spatially and functionally separated in the plastids of higher plants. Plant Physiol Biochem 47:518–525PubMedCrossRefGoogle Scholar
  17. Kouranov A, Schnell DJ (1997) Analysis of the interactions of preproteins with the import machinery over the course of protein import into chloroplasts. J Cell Biol 139:1677–1685PubMedCrossRefGoogle Scholar
  18. Kouranov A, Chen X, Fuks B, Schnell DJ (1998) Tic20 and Tic22 are new components of the protein import apparatus at the chloroplast inner envelope membrane. J Cell Biol 143:991–1002PubMedCrossRefGoogle Scholar
  19. Kouranov A, Wang H, Schnell DJ (1999) Tic22 is targeted to the intermembrane space of chloroplasts by a novel pathway. J Biol Chem 274:25181–25186PubMedCrossRefGoogle Scholar
  20. Li W, Godzik A (2006) Cd-hit: a fast program for clustering and comparing large sets of protein or nucleotide sequences. Bioinformatics 22:1658–1659PubMedCrossRefGoogle Scholar
  21. Li M, Schnell DJ (2006) Reconstitution of protein targeting to the inner envelope membrane of chloroplasts. J Cell Biol 175:249–259PubMedCrossRefGoogle Scholar
  22. Lübeck J, Heins L, Soll J (1997) A nuclear-coded chloroplastic inner envelope membrane protein uses a soluble sorting intermediate upon import into the organelle. J Cell Biol 137:1279–1286PubMedCrossRefGoogle Scholar
  23. Lyck R, Harmening U, Hohfeld I, Treuter E, Scharf KD, Nover L (1997) Intracellular distribution and identification of the nuclear localization signals of two plant heat-stress transcription factors. Planta 202:117–125PubMedCrossRefGoogle Scholar
  24. Millar AH, Carrie C, Pogson B, Whelan J (2009) Exploring the function-location nexus: using multiple lines of evidence in defining the subcellular location of plant proteins. Plant Cell 21:1625–1631PubMedCrossRefGoogle Scholar
  25. Mishra SK, Tripp J, Winkelhaus S, Tschiersch B, Theres K, Nover L, Scharf KD (2002) In the complex family of heat stress transcription factors, HsfA1 has a unique role as master regulator of thermotolerance in tomato. Genes Dev 16:1555–1567PubMedCrossRefGoogle Scholar
  26. Reumann S, Keegstra K (1999) The endosymbiotic origin of the protein import machinery of chloroplastic envelope membranes. Trends Plant Sci 4:302–307PubMedCrossRefGoogle Scholar
  27. Schleiff E, Becker T (2011) Common ground for protein translocation: access control for mitochondria and chloroplasts. Nat Rev Mol Cell Biol 12:48–59PubMedCrossRefGoogle Scholar
  28. Schleiff E, Tien R, Salomon M, Soll J (2001) Lipid composition of outer leaflet of chloroplast outer envelope determines topology of OEP7. Mol Biol Cell 12:4090–4102PubMedGoogle Scholar
  29. Schwacke R, Schneider A, van der Graaff E, Fischer K, Catoni E, Desimone M, Frommer WB, Flugge UI, Kunze R (2003) ARAMEMNON, a novel database for Arabidopsis integral membrane proteins. Plant Physiol 131:16–26PubMedCrossRefGoogle Scholar
  30. Tranel PJ, Froehlich J, Goyal A, Keegstra K (1995) A component of the chloroplastic protein import apparatus is targeted to the outer envelope membrane via a novel pathway. EMBO J 14:2436–2446PubMedGoogle Scholar
  31. Tripp J, Inoue K, Keegstra K, Froehlich JE (2007) A novel serine/proline-rich domain in combination with a transmembrane domain is required for the insertion of AtTic40 into the inner envelope membrane of chloroplasts. Plant J 52:824–838PubMedCrossRefGoogle Scholar
  32. Tusnády GE, Simon I (2001) The HMMTOP transmembrane topology prediction server. Bioinformatics 17:849–850PubMedCrossRefGoogle Scholar
  33. van Dooren GG, Tomova C, Agrawal S, Humbel BM, Striepen B (2008) Toxoplasma gondii Tic20 is essential for apicoplast protein import. Proc Natl Acad Sci USA 105:13574–13579PubMedCrossRefGoogle Scholar
  34. von Arnim AG, Deng XW, Stacey MG (1998) Cloning vectors for the expression of green fluorescent protein fusion proteins in transgenic plants. Gene 221:35–43CrossRefGoogle Scholar
  35. von Heijne G, Gavel Y (1988) Topogenic signals in integral membrane proteins. Eur J Biochem 174:671–678CrossRefGoogle Scholar
  36. Zimmermann P, Hirsch-Hoffmann M, Hennig L, Gruissem W (2004) GENEVESTIGATOR. Arabidopsis microarray database and analysis toolbox. Plant Physiol 136:2621–2632PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Anu B. Machettira
    • 2
  • Lucia E. Gross
    • 2
  • Maik S. Sommer
    • 2
  • Benjamin L. Weis
    • 2
  • Gisela Englich
    • 2
  • Joanna Tripp
    • 2
    Email author
  • Enrico Schleiff
    • 1
    • 2
    Email author
  1. 1.Department of Biosciences, Cluster of Excellence ‘Macromolecular Complexes, Center of Membrane ProteomicsJohann-Wolfgang-Goethe University FrankfurtFrankfurt am MainGermany
  2. 2.Department of Biosciences, Molecular Cell Biology of PlantsJohann-Wolfgang-Goethe University FrankfurtFrankfurt am MainGermany

Personalised recommendations