蛋白质酪氨酸磷酸化和氯通道参与瞬时受体电位蛋白介导钙池耗竭引起的钙内流

目的　探讨蛋白质酪氨酸磷酸化与Cl-通道对瞬时受体电位 (TRP)蛋白参与的Ca2 + 池耗竭引起的Ca2 + 内流(SOC)的调控作用。方法　采用脂质体转染和Fura 2 /AM荧光光度法 ,测定胞浆游离Ca2 +浓度 ( Ca2 + ]i) ,比较转染人源性TRP1 (hTRP1 )和人源性TRP3 (hTRP3 )cDNA对毒胡罗卜素 (TG)引起的Ca2 + 内流的作用 ,并观察酪氨酸激酶抑制剂染料木黄酮、Cl-通道阻断剂呋塞米和 4,4 二异硫氰基芪 2 ,2 二磺酸 (DIDS)对其的影响。结果　HEK2 93细胞转染hTRP1cDNA后 ,TG引起的Ca2 + 内流显著增加 ;转染hTRP3cDNA则无明显影响。 5～ 3 0 μmol·L-1染料木黄酮、1～ 8μmol·L-1呋塞米、0 .5～ 1μmol·L-1DIDS对转染hTRP1cDNA细胞的TG诱发的Ca2 + 内流均有抑制作用。结论　hTRP1蛋白可能是HEK2 93细胞SOC的物质基础 ;酪氨酸激酶和Cl-通道均参与HEK2 93细胞SOC的调控 ,而且酪氨酸激酶可能直接作用于TRP1蛋白

Involvment of protein tyrosine phosphorylation and chloride channel in transient receptor potential protein mediated storeoperated calcium influx

AIM To investigate whether protein tyrosine phosphorylation and Cl^- channels be involved in transient receptor potential(TRP) protein mediated store-operated calcium influx(SOC) in HEK293 cells. METHODS Human TRP1(hTRP1) and human TRP3(hTRP3) cDNA were transfected to HEK293 cells respectively using lipofectAMINE reagent, the effects of genistei n, furosemide and 4,4-diisothiocyanostilbene-2,2-disulphonic acid(DIDS) on thapsigargin(TG)-induced Ca²⁺ influx were determined by Fura-2/AM spectrophoto-fluorometry. RESULTS Compared with untransfected cells, the significant enhancement in TG- induced Ca²⁺ influx in hTRP1-transfected HEK293 cells was found, but not in hTRP3- transfected ones. Genistein 5－30 μmol·L^-1, furosemide 1－8 μmol·L^-1 and DIDS 0.5－1.0 μmol·L^-1 inhibited TG-induced Ca²⁺ influx in hTRP1- transfected cells. CONCLUSION hTRP1 Protein may be one of components of TG-induced SOC in transfected HEK293 cells. Tyrosine phosphorylation and Cl^- channels may be involved in TG-induced Ca²⁺ influx and tyrosine kinase may regulate hTRP1 protein directly.