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ATP‐dependent regulation of nuclear Ca 2+ levels in plant cells
Author(s) -
Bunney Tom D.,
Shaw Peter J.,
Watkins Peter A.C.,
Taylor J.Philip,
Beven Alison F.,
Wells Brian,
Calder Grant M.,
Drøbak Bjørn K.
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01709-9
Subject(s) - chemistry , plant cell , biophysics , microbiology and biotechnology , biochemistry , biology , gene
Localised alterations in cytoplasmic Ca 2+ levels are an integral part of the response of eukaryotic cells to a plethora of external stimuli. Due to the large size of nuclear pores, it has generally been assumed that intranuclear Ca 2+ levels reflect the prevailing cytoplasmic Ca 2+ levels. Using nuclei prepared from carrot ( Daucus carota L.) cells, we now show that Ca 2+ can be transported across nuclear membranes in an ATP‐dependent manner and that over 95% of Ca 2+ is accumulated into a pool releasable by the Ca 2+ ionophore A.23187. ATP‐dependent nuclear Ca 2+ uptake did not occur in the presence of ADP or ADPγS and was abolished by orthovanadate. Confocal microscopy of nuclei loaded with dextran‐linked Indo‐1 showed that the initial ATP‐induced rise in [Ca 2+ ] occurs in the nuclear periphery. The occurrence of ATP‐dependent Ca 2+ uptake in plant nuclei suggests that alterations of intranuclear Ca 2+ levels may occur independently of cytoplasmic [Ca 2+ ] changes.