Abstract
Unlike most other characterized organic solute transport in plants, uptake of the model compound S-(2,4-dinitrophenyl)glutathione (DNP-GS) and related glutathione-S-conjugated by vacuolar membranes is directly energized by MgATP. Here we show that exogenous application of the DNP-GS precursor 1-chloro-2,4-dinitrobenzene (CDNB) to seedlings of Vigna radiata (mung bean) increases the capacity of vacuolar membrane vesicles isolated from hypocotyls for MgATP-dependent DNP-GS transport in vitro. Our findings are 4-fold: (a) Pretreatment of seedlings with CDNB causes a progressive increase in MgATP-dependent DNP-GS uptake by vacuolar membrane vesicles, whereas the same range of CDNB concentrations causes only marginal stimulation when the compound benoxacor [4-(dichloroacetyl)-3,4-dihydro-3-methyl-2H-1,4-benzoxazine] is included in the pretreatment solution. (b) Increased DNP-GS uptake is accompanied by a proportionate and selective increase in Vmax(DNP-GS) but not in Km(DNP-GS) or Km(MgATP). (c) CDNB-enhanced DNP-GS uptake is not accompanied by a change in the density profile or sidedness of the vacuolar membrane fraction. (d) Basal and CDNB-enhanced DNP-GS uptake are indistinguishable in terms of their inhibitor profiles. On the basis of these findings, it is inferred that pretreatment with CDNB increases the amount or recruitment of functional transporter into the vacuolar membrane and that agents such as benoxacor antagonize the effects otherwise seen with CDNB in this sytem.
Full Text
The Full Text of this article is available as a PDF (855.8 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Akerboom T. P., Narayanaswami V., Kunst M., Sies H. ATP-dependent S-(2,4-dinitrophenyl)glutathione transport in canalicular plasma membrane vesicles from rat liver. J Biol Chem. 1991 Jul 15;266(20):13147–13152. [PubMed] [Google Scholar]
- Fuerst E. P., Irzyk G. P., Miller K. D. Partial Characterization of Glutathione S-Transferase Isozymes Induced by the Herbicide Safener Benoxacor in Maize. Plant Physiol. 1993 Jul;102(3):795–802. doi: 10.1104/pp.102.3.795. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Habig W. H., Pabst M. J., Jakoby W. B. Glutathione S-transferases. The first enzymatic step in mercapturic acid formation. J Biol Chem. 1974 Nov 25;249(22):7130–7139. [PubMed] [Google Scholar]
- Higgins C. F. ABC transporters: from microorganisms to man. Annu Rev Cell Biol. 1992;8:67–113. doi: 10.1146/annurev.cb.08.110192.000435. [DOI] [PubMed] [Google Scholar]
- Ishikawa T. ATP/Mg2+-dependent cardiac transport system for glutathione S-conjugates. A study using rat heart sarcolemma vesicles. J Biol Chem. 1989 Oct 15;264(29):17343–17348. [PubMed] [Google Scholar]
- Ishikawa T. The ATP-dependent glutathione S-conjugate export pump. Trends Biochem Sci. 1992 Nov;17(11):463–468. doi: 10.1016/0968-0004(92)90489-v. [DOI] [PubMed] [Google Scholar]
- Kitamura T., Jansen P., Hardenbrook C., Kamimoto Y., Gatmaitan Z., Arias I. M. Defective ATP-dependent bile canalicular transport of organic anions in mutant (TR-) rats with conjugated hyperbilirubinemia. Proc Natl Acad Sci U S A. 1990 May;87(9):3557–3561. doi: 10.1073/pnas.87.9.3557. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kobayashi K., Sogame Y., Hayashi K., Nicotera P., Orrenius S. ATP stimulates the uptake of S-dinitrophenylglutathione by rat liver plasma membrane vesicles. FEBS Lett. 1988 Nov 21;240(1-2):55–58. doi: 10.1016/0014-5793(88)80339-9. [DOI] [PubMed] [Google Scholar]
- Kunst M., Sies H., Akerboom T. P. ATP-stimulated uptake of S-(2,4-dinitrophenyl)glutathione by plasma membrane vesicles from rat liver. Biochim Biophys Acta. 1989 Jul 24;983(1):123–125. doi: 10.1016/0005-2736(89)90389-1. [DOI] [PubMed] [Google Scholar]
- LaBelle E. F., Singh S. V., Srivastava S. K., Awasthi Y. C. Evidence for different transport systems for oxidized glutathione and S-dinitrophenyl glutathione in human erythrocytes. Biochem Biophys Res Commun. 1986 Sep 14;139(2):538–544. doi: 10.1016/s0006-291x(86)80024-9. [DOI] [PubMed] [Google Scholar]
- Li Z. S., Zhao Y., Rea P. A. Magnesium Adenosine 5[prime]-Triphosphate-Energized Transport of Glutathione-S-Conjugates by Plant Vacuolar Membrane Vesicles. Plant Physiol. 1995 Apr;107(4):1257–1268. doi: 10.1104/pp.107.4.1257. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Peterson G. L. A simplification of the protein assay method of Lowry et al. which is more generally applicable. Anal Biochem. 1977 Dec;83(2):346–356. doi: 10.1016/0003-2697(77)90043-4. [DOI] [PubMed] [Google Scholar]
- Rea P. A., Britten C. J., Sarafian V. Common identity of substrate binding subunit of vacuolar h-translocating inorganic pyrophosphatase of higher plant cells. Plant Physiol. 1992 Oct;100(2):723–732. doi: 10.1104/pp.100.2.723. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wareing C. J., Black S. M., Hayes J. D., Wolf C. R. Increased levels of alpha-class and pi-class glutathione S-transferases in cell lines resistant to 1-chloro-2,4-dinitrobenzene. Eur J Biochem. 1993 Oct 15;217(2):671–676. doi: 10.1111/j.1432-1033.1993.tb18292.x. [DOI] [PubMed] [Google Scholar]
- Zhen R. G., Kim E. J., Rea P. A. Localization of cytosolically oriented maleimide-reactive domain of vacuolar H(+)-pyrophosphatase. J Biol Chem. 1994 Sep 16;269(37):23342–23350. [PubMed] [Google Scholar]
- Zimniak P., Awasthi Y. C. ATP-dependent transport systems for organic anions. Hepatology. 1993 Feb;17(2):330–339. [PubMed] [Google Scholar]