Abstract
Using a radioligand-binding assay we have identified a Ca2+- dependent high-affinity D-myo-inositol-1,4,5-trisphosphate (InsP3) binding site in a membrane vesicle preparation from Chenopodium rubrum. Millimolar concentrations of Ca2+ were required to observe specific binding of [3H]InsP3. A stable equilibrium between bound and free ligand was established within 5 min and bound [3H]InsP3 could be completely displaced by InsP3 in a time- and concentration-dependent manner. Displacement assays indicated a single class of binding sites with an estimated dissociation constant of 142 [plus or minus] 17 nM. Other inositol phosphates bound to the receptor with much lower affinity. The glycosaminoglycan heparin was an effective competitor for the binding site (inhibitor concentration for 50% displacement = 534 nM). ATP at higher, although physiologically relevant, concentrations (inhibitor concentration for 50% displacement = 241 [mu]M) also displaced [3H]InsP3 from the receptor. Recent studies in animals have highlighted the importance of Ca2+ regulation of InsP3-induced Ca2+ release. The potential for the operation of similar regulatory mechanisms in plants is discussed.
Full Text
The Full Text of this article is available as a PDF (846.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Berridge M. J. Inositol trisphosphate and calcium signalling. Nature. 1993 Jan 28;361(6410):315–325. doi: 10.1038/361315a0. [DOI] [PubMed] [Google Scholar]
- Bethke P. C., Jones R. L. Ca2+-Calmodulin Modulates Ion Channel Activity in Storage Protein Vacuoles of Barley Aleurone Cells. Plant Cell. 1994 Feb;6(2):277–285. doi: 10.1105/tpc.6.2.277. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Biswas S., Dalal B., Sen M., Biswas B. B. Receptor for myo-inositol trisphosphate from the microsomal fraction of Vigna radiata. Biochem J. 1995 Mar 15;306(Pt 3):631–636. doi: 10.1042/bj3060631. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brosnan J. M., Sanders D. Identification and Characterization of High-Affinity Binding Sites for Inositol Trisphosphate in Red Beet. Plant Cell. 1993 Aug;5(8):931–940. doi: 10.1105/tpc.5.8.931. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Callamaras N., Parker I. Inositol 1,4,5-trisphosphate receptors in Xenopus laevis oocytes: localization and modulation by Ca2+. Cell Calcium. 1994 Jan;15(1):66–78. doi: 10.1016/0143-4160(94)90105-8. [DOI] [PubMed] [Google Scholar]
- Danoff S. K., Ferris C. D., Donath C., Fischer G. A., Munemitsu S., Ullrich A., Snyder S. H., Ross C. A. Inositol 1,4,5-trisphosphate receptors: distinct neuronal and nonneuronal forms derived by alternative splicing differ in phosphorylation. Proc Natl Acad Sci U S A. 1991 Apr 1;88(7):2951–2955. doi: 10.1073/pnas.88.7.2951. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Drobak B. K. Plant Phosphoinositides and Intracellular Signaling. Plant Physiol. 1993 Jul;102(3):705–709. doi: 10.1104/pp.102.3.705. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Furuichi T., Kohda K., Miyawaki A., Mikoshiba K. Intracellular channels. Curr Opin Neurobiol. 1994 Jun;4(3):294–303. doi: 10.1016/0959-4388(94)90089-2. [DOI] [PubMed] [Google Scholar]
- Föhr K. J., Warchol W., Gratzl M. Calculation and control of free divalent cations in solutions used for membrane fusion studies. Methods Enzymol. 1993;221:149–157. doi: 10.1016/0076-6879(93)21014-y. [DOI] [PubMed] [Google Scholar]
- Gilroy S., Fricker M. D., Read N. D., Trewavas A. J. Role of Calcium in Signal Transduction of Commelina Guard Cells. Plant Cell. 1991 Apr;3(4):333–344. doi: 10.1105/tpc.3.4.333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gilroy S., Read N. D., Trewavas A. J. Elevation of cytoplasmic calcium by caged calcium or caged inositol triphosphate initiates stomatal closure. Nature. 1990 Aug 23;346(6286):769–771. doi: 10.1038/346769a0. [DOI] [PubMed] [Google Scholar]
- Hughes P. J., Michell R. H. Novel inositol containing phospholipids and phosphates: their synthesis and possible new roles in cellular signalling. Curr Opin Neurobiol. 1993 Jun;3(3):383–400. doi: 10.1016/0959-4388(93)90132-i. [DOI] [PubMed] [Google Scholar]
- Iino M., Tsukioka M. Feedback control of inositol trisphosphate signalling bycalcium. Mol Cell Endocrinol. 1994 Jan;98(2):141–146. doi: 10.1016/0303-7207(94)90132-5. [DOI] [PubMed] [Google Scholar]
- Marshall I. C., Taylor C. W. Two calcium-binding sites mediate the interconversion of liver inositol 1,4,5-trisphosphate receptors between three conformational states. Biochem J. 1994 Jul 15;301(Pt 2):591–598. doi: 10.1042/bj3010591. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mauger J. P., Lièvremont J. P., Piétri-Rouxel F., Hilly M., Coquil J. F. The inositol 1,4,5-trisphosphate receptor: kinetic properties and regulation. Mol Cell Endocrinol. 1994 Jan;98(2):133–139. doi: 10.1016/0303-7207(94)90131-7. [DOI] [PubMed] [Google Scholar]
- McAinsh M. R., Brownlee C., Hetherington A. M. Visualizing Changes in Cytosolic-Free Ca2+ during the Response of Stomatal Guard Cells to Abscisic Acid. Plant Cell. 1992 Sep;4(9):1113–1122. doi: 10.1105/tpc.4.9.1113. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pietri F., Hilly M., Mauger J. P. Calcium mediates the interconversion between two states of the liver inositol 1,4,5-trisphosphate receptor. J Biol Chem. 1990 Oct 15;265(29):17478–17485. [PubMed] [Google Scholar]
- Poovaiah B. W., Reddy A. S. Calcium and signal transduction in plants. CRC Crit Rev Plant Sci. 1993;12(3):185–211. doi: 10.1080/07352689309701901. [DOI] [PubMed] [Google Scholar]
- Ross C. A., Danoff S. K., Schell M. J., Snyder S. H., Ullrich A. Three additional inositol 1,4,5-trisphosphate receptors: molecular cloning and differential localization in brain and peripheral tissues. Proc Natl Acad Sci U S A. 1992 May 15;89(10):4265–4269. doi: 10.1073/pnas.89.10.4265. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Taylor C. W., Marshall I. C. Calcium and inositol 1,4,5-trisphosphate receptors: a complex relationship. Trends Biochem Sci. 1992 Oct;17(10):403–407. doi: 10.1016/0968-0004(92)90009-x. [DOI] [PubMed] [Google Scholar]
- Walton T. J., Cooke C. J., Newton R. P., Smith C. J. Evidence that generation of inositol 1,4,5-trisphosphate and hydrolysis of phosphatidylinositol 4,5-bisphosphate are rapid responses following addition of fungal elicitor which induces phytoalexin synthesis in lucerne (Medicago sativa) suspension culture cells. Cell Signal. 1993 May;5(3):345–356. doi: 10.1016/0898-6568(93)90026-i. [DOI] [PubMed] [Google Scholar]
- Worley P. F., Baraban J. M., Supattapone S., Wilson V. S., Snyder S. H. Characterization of inositol trisphosphate receptor binding in brain. Regulation by pH and calcium. J Biol Chem. 1987 Sep 5;262(25):12132–12136. [PubMed] [Google Scholar]
- Wreggett K. A., Irvine R. F. Automated isocratic high-performance liquid chromatography of inositol phosphate isomers. Biochem J. 1989 Sep 15;262(3):997–1000. doi: 10.1042/bj2620997. [DOI] [PMC free article] [PubMed] [Google Scholar]
