title: An ATP signalling pathway in plant cells: extracellular ATP triggers programmed cell death in Populus euphratica.
abstract: We elucidated the extracellular ATP (eATP) signalling cascade active in programmed cell death (PCD) using cell cultures of Populus euphratica. Millimolar amounts of eATP induced a dose- and time-dependent reduction in viability, and the agonist-treated cells displayed hallmark features of PCD. eATP caused an elevation of cytosolic Ca(2+)  levels, resulting in Ca(2+)  uptake by the mitochondria and subsequent H(2) O(2)  accumulation. P. euphratica exhibited an increased mitochondrial transmembrane potential, and cytochrome c was released without opening of the permeability transition pore over the period of ATP stimulation. Moreover, the eATP-induced increase of intracellular ATP, essential for the activation of caspase-like proteases and subsequent PCD, was found to be related to increased mitochondrial transmembrane potential. NO is implicated as a downstream component of the cytosolic Ca(2+)  concentration but plays a negligible role in eATP-stimulated cell death. We speculate that ATP binds purinoceptors in the plasma membrane, leading to the induction of downstream intermediate signals, as the proposed sequence of events in PCD signalling was terminated by the animal P2 receptor antagonist suramin.
authors: National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University (Box 162), Beijing 100083 College of Life Science, Xuzhou Normal University, Xuzhou 221116, Jiangsu, China.
authors: Jian
authors: J
authors: Sun
authors: Chun-Lan
authors: CL
authors: Zhang
authors: Shu-Rong
authors: SR
authors: Deng
authors: Cun-Fu
authors: CF
authors: Lu
authors: Xin
authors: X
authors: Shen
authors: Xiao-Yang
authors: XY
authors: Zhou
authors: Xiao-Jiang
authors: XJ
authors: Zheng
authors: Zan-Min
authors: ZM
authors: Hu
authors: Shao-Liang
authors: SL
authors: Chen
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001692:Biological Transport; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D002470:Cell Survival; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D003624:Darkness; D005110:Extracellular Space / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008027:Light; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009569:Nitric Oxide / Q000378:metabolism; D010539:Permeability / Q000187:drug effects; D018520:Plant Shoots; D032107:Populus / Q000187:drug effects* / Q000502:physiology* / Q000528:radiation effects / Q000648:ultrastructure; D011983:Receptors, Purinergic / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013498:Suramin / Q000494:pharmacology
chemical_list: D011983:Receptors, Purinergic; D009569:Nitric Oxide; D013498:Suramin; D000255:Adenosine Triphosphate; D045304:Cytochromes c; D006861:Hydrogen Peroxide; D002118:Calcium