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Updated: Aug 14, 2026

Imaging Initial Ca2+ Microdomains in Primary T Cells
Published on: October 4, 2024
Activation of T cell calcium influx by the second messenger ADP-ribose
Andreas Gasser1, Günter Glassmeier, Ralf Fliegert
1University Medical Center Hamburg-Eppendorf, Center of Experimental Medicine, Institute of Biochemistry and Molecular Biology I: Cellular Signal Transduction.
Abstract:
Stimulation of Jurkat T cells by high concentrations of concanavalin A (ConA) induced an elevation of the endogenous adenosine diphosphoribose (ADPR) concentration and an inward current significantly different from the Ca2+ release-activated Ca2+ current (I(CRAC)). Electrophysiological characterization and activation of a similar current by infusion of ADPR indicated that the ConA-induced current is carried by TRPM2. Expression of TRPM2 in the plasma membrane of Jurkat T cells was demonstrated by reverse transcription-PCR, Western blot, and immunofluorescence. Inhibition of ADPR formation reduced ConA-mediated, but not store-operated, Ca2+ entry and prevented ConA-induced cell death of Jurkat cells. Moreover, gene silencing of TRPM2 abolished the ADPR- and ConA-mediated inward current. Thus, ADPR is a novel second messenger significantly involved in ConA-mediated cell death in T cells.
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