INOSITOL 1,3,4,5-TETRAKISPHOSPHATE-INDUCED RELEASE OF INTRACELLULAR CA-2+ IN SH-SY5Y NEUROBLASTOMA-CELLS

被引:60
作者
GAWLER, DJ [1 ]
POTTER, BVL [1 ]
NAHORSKI, SR [1 ]
机构
[1] UNIV LEICESTER,DEPT CHEM,LEICESTER LE1 9HN,ENGLAND
关键词
D O I
10.1042/bj2720519
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Inositol-polyphosphate-induced Ca2+ mobilization was investigated in saponin-permeabilized SH-SY5Y human neuroblastoma cells. Ins(1,4,5)P3 induced a dose-related release from intracellular Ca2+ stores with an EC50 (concn. giving half-maximal effect) of 0.1 μM and a maximal release of 70%. Ins(1,3,4)P3, DL-Ins(1,4,5,6)P4 and Ins(1,3,4,5,6)P5 did not evoke Ca2+ mobilization in these cells when used at concentrations up to 10 μM. However, Ins(1,3,4,5)P4 was found to release Ca2+ in a dose-related manner, but the response was dependent on the source of Ins(1,3,4,5)P4 used. When commercially available D-Ins(1,3,4,5)P4 was used, the EC50 and maximal response values were 1 μM and 50% respectively, compared with values for chemically synthesized DL-Ins(1,3,4,5)P4 of 2 μM and 25%. The enhanced maximal response of commercial D-Ins(1,3,4,5)P4 was decreased by pretreatment with rat brain crude Ins(1,4,5)P3 3-kinase and was therefore concluded to be indicative of initial Ins(1,4,5)P3 contamination of the Ins(1,3,4,5)P4 preparation. When metabolism of DL-Ins(1,3,4,5)P4 (10 μM) in these cells at 25°C was investigated by h.p.l.c., substantial amounts of Ins(1,4,5)P3 (0.2 μM) and Ins(1,3,4)P3 (0.8 μM) were found to be produced within 3 min. Analysis of DL-Ins(1,3,4,5)P4 incubation with cells at 4°C, however, indicated that metabolism had been arrested ([3H]Ins(1,4,5)P3 detection limits were estimated to be approx. 0.01 μM). When chemically synthesized DL-Ins(1,3,4,5)P4 and incubation conditions of low temperature were used, the Ca2+-releasing properties of this compound were established to be 1 μM and 19% for the EC50 and maximal response values respectively. The results obtained strongly suggest that Ins(1,3,4,5)P4 alone has the ability to release intracellular Ca2+. However, in the presence of sub-maximal concentrations of Ins(1,4,5)P3, Ca2+ release appears to be synergistic with Ins(1,3,4,5)P4, but at supramaximal concentrations not even additive effects are observed.
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页码:519 / 524
页数:6
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共 32 条
[21]   INOSITOL(1,3,4,5)TETRAKISPHOSPHATE-INDUCED ACTIVATION OF SEA-URCHIN EGGS REQUIRES THE PRESENCE OF INOSITOL TRISPHOSPHATE [J].
IRVINE, RF ;
MOOR, RM .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1987, 146 (01) :284-290
[22]   INOSITOL 1,3,4,5-TETRAKISPHOSPHATE INCREASES THE DURATION OF THE INOSITOL 1,4,5-TRISPHOSPHATE-MEDIATED CA-2+ TRANSIENT [J].
JOSEPH, SK ;
HANSEN, CA ;
WILLIAMSON, JR .
FEBS LETTERS, 1987, 219 (01) :125-129
[23]  
JOSEPH SK, 1989, MOL PHARMACOL, V36, P391
[24]   INOSITOL POLYPHOSPHATES AND INTRACELLULAR CALCIUM RELEASE [J].
JOSEPH, SK ;
WILLIAMSON, JR .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1989, 273 (01) :1-15
[25]   INOSITOL PHOSPHATES - PROFUSION AND CONFUSION [J].
MICHELL, B .
NATURE, 1986, 319 (6050) :176-177
[26]   SYNERGISM OF INOSITOL TRISPHOSPHATE AND TETRAKISPHOSPHATE IN ACTIVATING CA-2+-DEPENDENT K+ CHANNELS [J].
MORRIS, AP ;
GALLACHER, DV ;
IRVINE, RF ;
PETERSEN, OH .
NATURE, 1987, 330 (6149) :653-655
[27]   INOSITOL POLYPHOSPHATES AND NEURONAL CALCIUM HOMEOSTASIS [J].
NAHORSKI, SR .
TRENDS IN NEUROSCIENCES, 1988, 11 (10) :444-448
[28]   MOLECULAR RECOGNITION OF INOSITOL POLYPHOSPHATES BY INTRACELLULAR RECEPTORS AND METABOLIC ENZYMES [J].
NAHORSKI, SR ;
POTTER, BVL .
TRENDS IN PHARMACOLOGICAL SCIENCES, 1989, 10 (04) :139-&
[29]   METABOLISM OF THE INOSITOL PHOSPHATES PRODUCED UPON RECEPTOR ACTIVATION [J].
SHEARS, SB .
BIOCHEMICAL JOURNAL, 1989, 260 (02) :313-324
[30]  
SNYDER PM, 1988, J BIOL CHEM, V263, P11048