Ca2+ entry induced by cyclic ADP-ribose in intact T-lymphocytes.

TY - JOUR

T1 - Ca2+ entry induced by cyclic ADP-ribose in intact T-lymphocytes.

AU - Guse, A H

AU - Berg, I

AU - Da Silva, C P

AU - Potter, B V

AU - Mayr, Georg W.

PY - 1997

Y1 - 1997

N2 - Cyclic ADP-ribose (cADPr) is a potent Ca2+-mobilizing natural compound (Lee, H. C., Walseth, T. F., Bratt, G. T., Hayes, R. N., and Clapper, D. L. (1989) J. Biol. Chem. 264, 1608-1615) which has been shown to release Ca2+ from an intracellular store of permeabilized T-lymphocytes (Guse, A. H., Silva, C. P., Emmrich, F., Ashamu, G., Potter, B. V. L., and Mayr, G. W. (1995) J. Immunol. 155, 3353-3359). Microinjection of cADPr into intact single T lymphocytes dose dependently induced repetitive but irregular Ca2+ spikes which were almost completely dependent on the presence of extracellular Ca2+. The Ca2+ spikes induced by cADPr could be blocked either by co-injection of cADPr with the specific antagonist 8-NH2-cADPr, by omission of Ca2+ from the medium, or by superfusion of the cells with Zn2+ or SK-F 96365. Ratiometric digital Ca2+ imaging revealed that single Ca2+ spikes were initiated at several sites ("hot spots") close to the plasma membrane. These hot spots then rapidly formed a circular zone of high Ca2+ concentration below the plasma membrane which subsequently propagated like a closing optical diaphragm into the center of the cell. Taken together these data indicate a role for cADPr in Ca2+ entry in T-lymphocytes.

AB - Cyclic ADP-ribose (cADPr) is a potent Ca2+-mobilizing natural compound (Lee, H. C., Walseth, T. F., Bratt, G. T., Hayes, R. N., and Clapper, D. L. (1989) J. Biol. Chem. 264, 1608-1615) which has been shown to release Ca2+ from an intracellular store of permeabilized T-lymphocytes (Guse, A. H., Silva, C. P., Emmrich, F., Ashamu, G., Potter, B. V. L., and Mayr, G. W. (1995) J. Immunol. 155, 3353-3359). Microinjection of cADPr into intact single T lymphocytes dose dependently induced repetitive but irregular Ca2+ spikes which were almost completely dependent on the presence of extracellular Ca2+. The Ca2+ spikes induced by cADPr could be blocked either by co-injection of cADPr with the specific antagonist 8-NH2-cADPr, by omission of Ca2+ from the medium, or by superfusion of the cells with Zn2+ or SK-F 96365. Ratiometric digital Ca2+ imaging revealed that single Ca2+ spikes were initiated at several sites ("hot spots") close to the plasma membrane. These hot spots then rapidly formed a circular zone of high Ca2+ concentration below the plasma membrane which subsequently propagated like a closing optical diaphragm into the center of the cell. Taken together these data indicate a role for cADPr in Ca2+ entry in T-lymphocytes.

M3 - SCORING: Zeitschriftenaufsatz

VL - 272

SP - 8546

EP - 8550

JO - J BIOL CHEM

JF - J BIOL CHEM

SN - 0021-9258

IS - 13

M1 - 13

ER -