Abstract
A plastome (chloroplast genome) mutant of tobacco, lutescens-1, displays abnormal degradation of the chloroplast-encoded polypeptides which form the core complex of photosystem II (PSII). Two nuclear- encoded proteins (present in polymorphic forms), which normally function in the water oxidation process of PSII, accumulate as larger size-class polypeptides in mutant thylakoid membranes. These accumulated proteins are intermediate in size between the full-length primary protein synthesized in the cytoplasm and the proteolytically processed mature polypeptides. Trypsin treatment of unstacked mutant thylakoids and of inside-out vesicle (PSII-enriched) preparations indicated that the intermediate size forms were correctly localized on the inner surface of the thylakoid membrane, but not surface-exposed in the same way as the mature proteins. Only one of the intermediate size- class proteins could be extracted by salt washes. We interpret these data to be consistent with the idea that the two imported proteins that function in the water oxidation step of photosynthesis and are localized in the loculus (the space within the thylakoid vesicles) undergo two-step processing. The second step in proteolytic processing may be related to transport through a second membrane (the first transport step through the chloroplast envelope having been completed); this step may be arrested in the mutant due to the absence of the PSII core complex.
Full Text
The Full Text of this article is available as a PDF (1.3 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Ellis R. J. Chloroplast protein synthesis: principles and problems. Subcell Biochem. 1983;9:237–261. doi: 10.1007/978-1-4613-3533-7_2. [DOI] [PubMed] [Google Scholar]
- Gasser S. M., Daum G., Schatz G. Import of proteins into mitochondria. Energy-dependent uptake of precursors by isolated mitochondria. J Biol Chem. 1982 Nov 10;257(21):13034–13041. [PubMed] [Google Scholar]
- Gasser S. M., Ohashi A., Daum G., Böhni P. C., Gibson J., Reid G. A., Yonetani T., Schatz G. Imported mitochondrial proteins cytochrome b2 and cytochrome c1 are processed in two steps. Proc Natl Acad Sci U S A. 1982 Jan;79(2):267–271. doi: 10.1073/pnas.79.2.267. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gianfagna T., Zeevaart J. A., Lusk W. J. Effect of photoperiod on the metabolism of deuterium-labeled gibberellin a(53) in spinach. Plant Physiol. 1983 May;72(1):86–89. doi: 10.1104/pp.72.1.86. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Govindjee, Kambara T., Coleman W. The electron donor side of photosystem II: the oxygen evolving complex. Photochem Photobiol. 1985 Aug;42(2):187–210. doi: 10.1111/j.1751-1097.1985.tb01559.x. [DOI] [PubMed] [Google Scholar]
- Gray J. C., Kung S. D., Wildman S. G. Origin of Nicotiana tabacum L. detected by polypeptide composition of Fraction I protein. Nature. 1974 Nov 15;252(5480):226–227. doi: 10.1038/252226a0. [DOI] [PubMed] [Google Scholar]
- Grebanier A. E., Coen D. M., Rich A., Bogorad L. Membrane proteins synthesized but not processed by isolated maize chloroplasts. J Cell Biol. 1978 Sep;78(3):734–746. doi: 10.1083/jcb.78.3.734. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leary J. J., Brigati D. J., Ward D. C. Rapid and sensitive colorimetric method for visualizing biotin-labeled DNA probes hybridized to DNA or RNA immobilized on nitrocellulose: Bio-blots. Proc Natl Acad Sci U S A. 1983 Jul;80(13):4045–4049. doi: 10.1073/pnas.80.13.4045. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mishkind M. L., Wessler S. R., Schmidt G. W. Functional determinants in transit sequences: import and partial maturation by vascular plant chloroplasts of the ribulose-1,5-bisphosphate carboxylase small subunit of Chlamydomonas. J Cell Biol. 1985 Jan;100(1):226–234. doi: 10.1083/jcb.100.1.226. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nakatani H. Y. Photosynthetic oxygen evolution does not require the participation of polypeptides of 16 and 24 kilodaltons. Biochem Biophys Res Commun. 1984 Apr 16;120(1):299–304. doi: 10.1016/0006-291x(84)91448-7. [DOI] [PubMed] [Google Scholar]
- Robinson C., Ellis R. J. Transport of proteins into chloroplasts. The precursor of small subunit of ribulose bisphosphate carboxylase is processed to the mature size in two steps. Eur J Biochem. 1984 Jul 16;142(2):343–346. doi: 10.1111/j.1432-1033.1984.tb08292.x. [DOI] [PubMed] [Google Scholar]
- Schmidt R. J., Gillham N. W., Boynton J. E. Processing of the precursor to a chloroplast ribosomal protein made in the cytosol occurs in two steps, one of which depends on a protein made in the chloroplast. Mol Cell Biol. 1985 May;5(5):1093–1099. doi: 10.1128/mcb.5.5.1093. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schmidt R. J., Myers A. M., Gillham N. W., Boynton J. E. Chloroplast ribosomal proteins of Chlamydomonas synthesized in the cytoplasm are made as precursors. J Cell Biol. 1984 Jun;98(6):2011–2018. doi: 10.1083/jcb.98.6.2011. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steinback K. E., Burke J. J., Arntzen C. J. Evidence for the role of surface-exposed segments of the light-harvesting complex in cation-mediated control of chloroplast structure and function. Arch Biochem Biophys. 1979 Jul;195(2):546–557. doi: 10.1016/0003-9861(79)90381-3. [DOI] [PubMed] [Google Scholar]
- Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]