Tags

Type your tag names separated by a space and hit enter

Visualization of phosphatidylinositol 4,5-bisphosphate in the plasma membrane of suspension-cultured tobacco BY-2 cells and whole Arabidopsis seedlings.
Plant J. 2007 Dec; 52(6):1014-26.PJ

Abstract

Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] is an important signalling lipid in mammalian cells, where it functions as a second-messenger precursor in response to agonist-dependent activation of phospholipase C (PLC) but also operates as a signalling molecule on its own. Much of the recent knowledge about it has come from a new technique to visualize PtdIns(4,5)P(2)in vivo, by expressing a green or yellow fluorescent protein (GFP or YFP) fused to the pleckstrin homology (PH) domain of human PLCdelta1 that specifically binds PtdIns(4,5)P(2). In this way, YFP-PH(PLCdelta1) has been shown to predominantly label the plasma membrane and to transiently translocate into the cytoplasm upon PLC activation in a variety of mammalian cell systems. In plants, biochemical studies have shown that PtdIns(4,5)P(2) is present in very small quantities, but knowledge of its localization and function is still very limited. In this study, we have used YFP-PH(PLCdelta1) to try monitoring PtdIns(4,5)P(2)/PLC signalling in stably-transformed tobacco Bright Yellow-2 (BY-2) cells and Arabidopsis seedlings. In both plant systems, no detrimental effects were observed, indicating that overexpression of the biosensor did not interfere with the function of PtdIns(4,5)P(2). Confocal imaging revealed that most of the YFP-PH(PLCdelta1) fluorescence was present in the cytoplasm, and not in the plasma membrane as in mammalian cells. Nonetheless, four conditions were found in which YFP-PH(PLCdelta1) was concentrated at the plasma membrane: (i) upon treatment with the PLC inhibitor U73122; (ii) in response to salt stress; (iii) as a gradient at the tip of growing root hairs; (iv) during the final stage of a BY-2 cell division. We conclude that PtdIns(4,5)P(2), as in animals, is present in the plasma membrane of plants, but that its concentration in most cells is too low to be detected by YFP-PH(PLCdelta1). Hence, the reporter remains unbound in the cytosol, making it unsuitable to monitor PLC signalling. Nonetheless, YFP-PH(PLCdelta1) is a valuable plant PtdIns(4,5)P(2) reporter, for it highlights specific cells and conditions where this lipid becomes abnormally concentrated in membranes, raising the question of what it is doing there. New roles for PtdIns(4,5)P(2) in plant cell signalling are discussed.

Authors+Show Affiliations

Section Plant Physiology, University of Amsterdam, Swammerdam Institute for Life Sciences, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17908156

Citation

van Leeuwen, Wessel, et al. "Visualization of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane of Suspension-cultured Tobacco BY-2 Cells and Whole Arabidopsis Seedlings." The Plant Journal : for Cell and Molecular Biology, vol. 52, no. 6, 2007, pp. 1014-26.
van Leeuwen W, Vermeer JE, Gadella TW, et al. Visualization of phosphatidylinositol 4,5-bisphosphate in the plasma membrane of suspension-cultured tobacco BY-2 cells and whole Arabidopsis seedlings. Plant J. 2007;52(6):1014-26.
van Leeuwen, W., Vermeer, J. E., Gadella, T. W., & Munnik, T. (2007). Visualization of phosphatidylinositol 4,5-bisphosphate in the plasma membrane of suspension-cultured tobacco BY-2 cells and whole Arabidopsis seedlings. The Plant Journal : for Cell and Molecular Biology, 52(6), 1014-26.
van Leeuwen W, et al. Visualization of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane of Suspension-cultured Tobacco BY-2 Cells and Whole Arabidopsis Seedlings. Plant J. 2007;52(6):1014-26. PubMed PMID: 17908156.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Visualization of phosphatidylinositol 4,5-bisphosphate in the plasma membrane of suspension-cultured tobacco BY-2 cells and whole Arabidopsis seedlings. AU - van Leeuwen,Wessel, AU - Vermeer,Joop E M, AU - Gadella,Theodorus W J,Jr AU - Munnik,Teun, Y1 - 2007/10/01/ PY - 2007/10/3/pubmed PY - 2008/3/20/medline PY - 2007/10/3/entrez SP - 1014 EP - 26 JF - The Plant journal : for cell and molecular biology JO - Plant J. VL - 52 IS - 6 N2 - Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] is an important signalling lipid in mammalian cells, where it functions as a second-messenger precursor in response to agonist-dependent activation of phospholipase C (PLC) but also operates as a signalling molecule on its own. Much of the recent knowledge about it has come from a new technique to visualize PtdIns(4,5)P(2)in vivo, by expressing a green or yellow fluorescent protein (GFP or YFP) fused to the pleckstrin homology (PH) domain of human PLCdelta1 that specifically binds PtdIns(4,5)P(2). In this way, YFP-PH(PLCdelta1) has been shown to predominantly label the plasma membrane and to transiently translocate into the cytoplasm upon PLC activation in a variety of mammalian cell systems. In plants, biochemical studies have shown that PtdIns(4,5)P(2) is present in very small quantities, but knowledge of its localization and function is still very limited. In this study, we have used YFP-PH(PLCdelta1) to try monitoring PtdIns(4,5)P(2)/PLC signalling in stably-transformed tobacco Bright Yellow-2 (BY-2) cells and Arabidopsis seedlings. In both plant systems, no detrimental effects were observed, indicating that overexpression of the biosensor did not interfere with the function of PtdIns(4,5)P(2). Confocal imaging revealed that most of the YFP-PH(PLCdelta1) fluorescence was present in the cytoplasm, and not in the plasma membrane as in mammalian cells. Nonetheless, four conditions were found in which YFP-PH(PLCdelta1) was concentrated at the plasma membrane: (i) upon treatment with the PLC inhibitor U73122; (ii) in response to salt stress; (iii) as a gradient at the tip of growing root hairs; (iv) during the final stage of a BY-2 cell division. We conclude that PtdIns(4,5)P(2), as in animals, is present in the plasma membrane of plants, but that its concentration in most cells is too low to be detected by YFP-PH(PLCdelta1). Hence, the reporter remains unbound in the cytosol, making it unsuitable to monitor PLC signalling. Nonetheless, YFP-PH(PLCdelta1) is a valuable plant PtdIns(4,5)P(2) reporter, for it highlights specific cells and conditions where this lipid becomes abnormally concentrated in membranes, raising the question of what it is doing there. New roles for PtdIns(4,5)P(2) in plant cell signalling are discussed. SN - 0960-7412 UR - https://www.unboundmedicine.com/medline/citation/17908156/Visualization_of_phosphatidylinositol_45_bisphosphate_in_the_plasma_membrane_of_suspension_cultured_tobacco_BY_2_cells_and_whole_Arabidopsis_seedlings_ L2 - https://doi.org/10.1111/j.1365-313X.2007.03292.x DB - PRIME DP - Unbound Medicine ER -