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InsP 3 ‐mediated calcium release induced by heterologous expression of total chicory Leaf RNA
Author(s) -
DebarbieuxDeleporte M.,
Delbreil B.,
Collin T.,
Delcourt P.,
Vasseur J.,
Prevarskaya N.,
OuadidAhidouch H.
Publication year - 2002
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1016/s0248-4900(02)00021-7
Subject(s) - extracellular , biology , xenopus , heterologous , calcium , signal transduction , microbiology and biotechnology , depolarization , rna , intracellular , calcium in biology , calcium signaling , heterologous expression , biochemistry , biophysics , medicine , recombinant dna , gene
Summry— A calcium dependent‐chloride current ( I ni ) was recorded in Xenopus oocytes injected with total RNA from chicory leaf tissues, following depolarization from −35 to +60 mV. However, the signal transduction mechanism mediating I ni is unknown. The development of this current was mimicked by intracellular injection of the second messenger InsP 3 in control (non‐injected) oocytes. Moreover, InsP 3 injection after I ni rundown did not reinitiate the current. The same phenomenon was observed following a second injection into control oocytes. Measurement of InsP 3 production in injected oocytes showed a net increase in the InsP 3 level on depolarization. Moreover, extracellular application of caffeine (5 mM) significantly reduced the number of oocytes displaying I ni . Also, extracellular application of U‐73122, a potent PLC inhibitor, clearly reduced the occurrence of I ni . These data provide the first evidence that the calcium homeostasis mechanism induced by heterologous expression of total RNA from chicory leaves involves the InsP 3 signaling pathway.