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. 1996 Jan;8(1):43–53. doi: 10.1105/tpc.8.1.43

A soluble protein is imported into Euglena chloroplasts as a membrane-bound precursor.

C Sulli 1, S D Schwartzbach 1
PMCID: PMC161080  PMID: 8597659

Abstract

The Euglena precursor to the small subunit of ribulose-15-bisphosphate carboxylase/oxygenase (pSSU) is a polyprotein. To determine the transport route from cytoplasm to chloroplast, Euglena was pulse labeled with 35S-sulfate and the organelles were separated on sucrose gradients. After a pulse, pSSU was found in the endoplasmic reticulum (ER) and Golgi apparatus. During a chase, ER-and Golgi-localized pSSU decreased concomitant with the appearance of SSU in chloroplasts. SSU was not found in pSSU-containing ER and Golgi fractions. Na2CO3 did not remove pSSU from ER or Golgi membranes, indicating that it was an integral membrane protein. pSSU was inserted in vitro into canine microsomes, and Na2CO3 did not remove pSSU from the microsomal membrane. The in vivo and in vitro experiments show that Euglena pSSU is inserted into the ER membrane and transported as an integral membrane protein to the Golgi apparatus before chloroplast import and polyprotein processing.

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Selected References

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  1. Bhaya D., Grossman A. Targeting proteins to diatom plastids involves transport through an endoplasmic reticulum. Mol Gen Genet. 1991 Oct;229(3):400–404. doi: 10.1007/BF00267462. [DOI] [PubMed] [Google Scholar]
  2. Henry R., Kapazoglou A., McCaffery M., Cline K. Differences between lumen targeting domains of chloroplast transit peptides determine pathway specificity for thylakoid transport. J Biol Chem. 1994 Apr 8;269(14):10189–10192. [PubMed] [Google Scholar]
  3. Keller M., Chan R. L., Tessier L. H., Weil J. H., Imbault P. Post-transcriptional regulation by light of the biosynthesis of Euglena ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit. Plant Mol Biol. 1991 Jul;17(1):73–82. doi: 10.1007/BF00036807. [DOI] [PubMed] [Google Scholar]
  4. Kishore R., Muchhal U. S., Schwartzbach S. D. The presequence of Euglena LHCPII, a cytoplasmically synthesized chloroplast protein, contains a functional endoplasmic reticulum-targeting domain. Proc Natl Acad Sci U S A. 1993 Dec 15;90(24):11845–11849. doi: 10.1073/pnas.90.24.11845. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Kroth-Pancic P. G. Nucleotide sequence of two cDNAs encoding fucoxanthin chlorophyll a/c proteins in the diatom Odontella sinensis. Plant Mol Biol. 1995 Feb;27(4):825–828. doi: 10.1007/BF00020236. [DOI] [PubMed] [Google Scholar]
  6. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  7. Osafune T., Klein S., Schiff J. A. Events surrounding the early development of Euglena chloroplasts. Structure of the developing proplastid in the first hours of illumination from serial sections of wild-type cells. J Ultrastruct Res. 1980 Oct;73(1):77–90. doi: 10.1016/0022-5320(80)90117-3. [DOI] [PubMed] [Google Scholar]
  8. Osafune T., Schiff J. A., Hase E. Stage-dependent localization of LHCP II apoprotein in the Golgi of synchronized cells of Euglena gracilis by immunogold electron microscopy. Exp Cell Res. 1991 Apr;193(2):320–330. doi: 10.1016/0014-4827(91)90103-2. [DOI] [PubMed] [Google Scholar]
  9. Perry S. E., Keegstra K. Envelope membrane proteins that interact with chloroplastic precursor proteins. Plant Cell. 1994 Jan;6(1):93–105. doi: 10.1105/tpc.6.1.93. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Robinson C., Klösgen R. B. Targeting of proteins into and across the thylakoid membrane--a multitude of mechanisms. Plant Mol Biol. 1994 Oct;26(1):15–24. doi: 10.1007/BF00039516. [DOI] [PubMed] [Google Scholar]
  11. Schiff J. A., Schwartzbach S. D., Osafune T., Hase E. Photocontrol and processing of LHCP II apoprotein in Euglena: possible role of Golgi and other cytoplasmic sites. J Photochem Photobiol B. 1991 Nov;11(2):219–236. doi: 10.1016/1011-1344(91)80262-g. [DOI] [PubMed] [Google Scholar]
  12. Schägger H., von Jagow G. Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the separation of proteins in the range from 1 to 100 kDa. Anal Biochem. 1987 Nov 1;166(2):368–379. doi: 10.1016/0003-2697(87)90587-2. [DOI] [PubMed] [Google Scholar]
  13. Shashidhara L. S., Lim S. H., Shackleton J. B., Robinson C., Smith A. G. Protein targeting across the three membranes of the Euglena chloroplast envelope. J Biol Chem. 1992 Jun 25;267(18):12885–12891. [PubMed] [Google Scholar]
  14. Shashidhara L. S., Smith A. G. Expression and subcellular location of the tetrapyrrole synthesis enzyme porphobilinogen deaminase in light-grown Euglena gracilis and three nonchlorophyllous cell lines. Proc Natl Acad Sci U S A. 1991 Jan 1;88(1):63–67. doi: 10.1073/pnas.88.1.63. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Spormann D. O., Heim J., Wolf D. H. Biogenesis of the yeast vacuole (lysosome). The precursor forms of the soluble hydrolase carboxypeptidase yscS are associated with the vacuolar membrane. J Biol Chem. 1992 Apr 25;267(12):8021–8029. [PubMed] [Google Scholar]
  16. Sulli C., Schwartzbach S. D. The polyprotein precursor to the Euglena light-harvesting chlorophyll a/b-binding protein is transported to the Golgi apparatus prior to chloroplast import and polyprotein processing. J Biol Chem. 1995 Jun 2;270(22):13084–13090. doi: 10.1074/jbc.270.22.13084. [DOI] [PubMed] [Google Scholar]

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