Intracellular calcium mobilization induces immediate early gene pip92 via Src and mitogen-activated protein kinase in immortalized hippocampal cells
Intracellular calcium mobilization induces immediate early gene pip92 via Src and mitogen-activated protein kinase in immortalized hippocampal cells
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DOI：
10.1074/jbc.m007492200
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发表时间：
2001-01-19
影响因子：
4.8
通讯作者：
Ahn, YS
中科院分区：
文献类型：
--
作者：
Chung, KC;Sung, JY;Ahn, YS
细胞内钙水平的调节在细胞存活、增殖和分化中起着重要作用。细胞可渗透的、促肿瘤的毒胡萝卜素通过抑制内质网Ca 2 +-ATP酶来提高细胞内钙水平。Src-酪氨酸激酶家族参与从细胞生长和细胞骨架重排到分化的广泛的细胞应答。即早基因pip 92在神经元细胞死亡以及细胞生长和分化中被诱导。为了解决细胞内钙动员细胞生长的分子机制，我们研究了毒胡萝卜素和随后的细胞内钙流入对pip 92表达在永生化大鼠海马H19-7细胞的影响。在H19-7细胞中，毒胡萝卜素诱导的细胞内钙离子水平的增加刺激pip 92的表达。瞬时转染的细胞与激酶失活的丝裂原活化蛋白激酶（MER）和Src激酶或预处理的化学MEK抑制剂PD 98059显着抑制毒胡萝卜素诱导的pip 92表达。当组成型活性v-Src或MEK过表达时，pip 92基因的转录活性显著增加。显性抑制因子Raf-l阻断毒胡萝卜素诱导的pip 92转录活性。在毒胡萝卜素诱导的pip 92表达过程中，转录因子Elk 1被激活。总之，这些结果表明，毒胡萝卜素通过Raf-MEK-细胞外信号调节蛋白激酶-以及Src激酶依赖性信号通路刺激细胞内钙离子水平的增加来刺激pip 92的表达。
Regulation of intracellular calcium levels plays a central role in cell survival, proliferation, and differentiation. A cell-permeable, tumor-promoting thapsigarin elevates the intracellular calcium levels by inhibiting endoplasmic reticulum Ca2+-ATPase. The Src-tyrosine kinase family is involved in a broad range of cellular responses ranging from cell growth and cytoskeletal rearrangement to differentiation. The immediate early gene pip92 is induced in neuronal cell death as well as cell growth and differentiation. To resolve the molecular mechanism of cell growth by intracellular calcium mobilization, we have examined the effect of thapsigargin and subsequent intracellular calcium influx on pip92 expression in immortalized rat hippocampal H19-7 cells. An increase of intracellular calcium ion levels induced by thapsigargin stimulated the expression of pip92 in H19-7 cells. Transient transfection of the cells with kinase-inactive mitogen-activated protein kinase kinase (MER) and Src kinase or pretreatment with the chemical MEK inhibitor PD98059 significantly inhibited pip92 expression induced by thapsigargin. When constitutively active v-Src or MEK was overexpressed, the transcriptional activity of the pip92 gene was markedly increased. Dominant inhibitory Raf-l blocked the transcriptional activity of pip92 induced by thapsigarin. The transcription factor Elk1 is activated during thapsigargin-induced pip92 expression, Taken together, these results suggest that an increase of intracellular calcium ion levels by thapsigargin stimulates the pip92 expression via Raf-MEK-extracellular signal-regulated protein kinase- as well as Src kinase-dependent signaling pathways.