Thapsigargin‐stimulated MAP kinase phosphorylation via CRAC channels and PLD activation: inhibitory action of docosahexaenoic acid

FEBS Letters

Hichami, Aziz¹  Khan, Naim Akhtar¹  Aires, Virginie¹  Denys, Anne¹ 

[1] Département de Physiologie, UPRES Lipides et Nutrition, Université de Bourgogne, Faculté des Sciences de la Vie, 6 Boulevard Gabriel, 21000 Dijon, France

关键词: Jurkat T-cell;    Thapsigargin;    Calcium;    Docosahexaenoic acid;    [Ca2+]i;    intracellular free calcium concentration;    CRAC;    Ca2+ release-activated Ca2+;    DAG;    diacylglycerol;    DHA;    docosahexaenoic acid;    ERK;    extracellular signal-regulated kinase;    MAPK;    mitogen-activated protein kinase;    PKC;    protein kinase C;    PLC;    phospholipase C;    PLD;    phospholipase D;    PMA;    phorbol 12-myristate 13-acetate;    PROP;    propranolol;    PUFA;    polyunsaturated fatty acid;    SOC;    store-operated calcium;    TA9;    tyrphostin A9;   

DOI  :  10.1016/S0014-5793(04)00361-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

This study was conducted on human Jurkat T-cells to investigate the role of depletion of intracellular Ca²⁺ stores in the phosphorylation of two mitogen-activated protein kinases (MAPKs), i.e. extracellular signal-regulated kinase (ERK) 1 and ERK2, and their modulation by a polyunsaturated fatty acid, docosahexaenoic acid (DHA). We observed that thapsigargin (TG) stimulated MAPK activation by store-operated calcium (SOC) influx via opening of calcium release-activated calcium (CRAC) channels as tyrphostin-A9, a CRAC channel blocker, and two SOC influx inhibitors, econazole and SKF-96365, diminished the action of the former. TG-stimulated ERK1/ERK2 phosphorylation was also diminished in buffer containing EGTA, a calcium chelator, further suggesting the implication of calcium influx in MAPK activation in these cells. Moreover, TG stimulated the production of diacylglycerol (DAG) by activating phospholipase D (PLD) as propranolol (PROP) (a PLD inhibitor), but not U73122 (a phospholipase C inhibitor), inhibited TG-evoked DAG production in these cells. DAG production and protein kinase C (PKC) activation were involved upstream of MAPK activation as PROP and GF109203X, a PKC inhibitor, abolished the action of TG on ERK1/ERK2 phosphorylation. Furthermore, DHA seems to act by inhibiting PKC activation as this fatty acid diminished TG- and phorbol 12-myristate 13-acetate-induced ERK1/ERK2 phosphorylation in these cells. Together these results suggest that Ca²⁺ influx via CRAC channels is implicated in PLD/PKC/MAPK activation which may be a target of physiological agents such as DHA.

【 授权许可】

Unknown