Trp1, a candidate protein for the store-operated Ca2+ influx mechanism in salivary gland cells
Trp1, a candidate protein for the store-operated Ca2+ influx mechanism in salivary gland cells
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DOI：
10.1074/jbc.275.5.3403
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发表时间：
2000-02-04
影响因子：
4.8
通讯作者：
Ambudkar, IS
中科院分区：
文献类型：
--
作者：
Liu, XB;Wang, WC;Ambudkar, IS
trp基因家族被认为编码钙池操纵的钙内流（SOC）通道。本研究探讨Trp 1在唾液腺细胞SOC机制中的作用。在人下颌下腺细胞系（HSG）中检测到htrp 1、htrp 3和Trp 1，稳定转染htrp 1 α cDNA的HSG细胞显示（i）更高水平的Trp 1，（ii）SOC增加3-5倍（毒胡萝卜素刺激的Ca 2+内流），通过[Ca 2 +]（i）和Ca 2+激活的K+通道电流测量确定，和（iii）相似的基础Ca 2+渗透性，Gd ~（3+）对SOC有抑制作用，而Zn ~（2+）对SOC无抑制作用。重要的是，（i）用反义Trp 1 α cDNA转染HSG细胞降低了内源性Trp 1水平并显著减弱了SOC，和（ii）用htrp 3 cDNA转染HSG细胞不增加SOC。这些数据证明了Trp 1和SOC之间的关联，并强烈地表明Trp 1参与了HSG细胞中的这种机制。与该建议一致，在质膜区域检测到Trp 1，完整大鼠下颌下腺腺泡和导管细胞SOC的拟定部位。基于这些汇总数据，我们建议Trp 1作为候选蛋白的SOC机制在唾液腺细胞。
The trp gene family has been proposed to encode the store operated Ca2+ influx (SOC) channel(s). This study examines the role of Trp1 in the SOC mechanism of salivary gland cells. htrp1, htrp3, and Trp1 were detected in the human submandibular gland cell line (HSG), HSG cells stably transfected with htrp1 alpha cDNA displayed (i) a higher level of Trp1, (ii) a 3-5-fold increase in SOC (thapsigargin-stimulated Ca2+ influx), determined by [Ca2+](i) and Ca2+-activated K+ channel current measurements, and (iii) similar basal Ca2+ permeability, and inhibition of SOC by Gd3+ but not by Zn2+, as compared with control cells. importantly, (i) transfection of HSG cells with antisense trp1 alpha cDNA decreased endogenous Trp1 level and significantly attenuated SOC, and (ii) transfection of HSG cells with htrp3 cDNA did not increase SOC, These data demonstrate an association between Trp1 and SOC and strongly suggest that Trp1 is involved in this mechanism in HSG cells, Consistent with this suggestion, Trp1 was detected in the plasma membrane region, the proposed site of SOC, of acinar and ductal cells in intact rat submandibular glands. Based on these aggregate data, we propose Trp1 as a candidate protein for the SOC mechanism in salivary gland cells.