Regulation of bFGF gene expression and subcellular distribution of bFGF protein in adrenal medullary cells.
Regulation of bFGF gene expression and subcellular distribution of bFGF protein in adrenal medullary cells.
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BFGF基因表达和肾上腺髓质细胞中BFGF蛋白的亚细胞分布的调节。
DOI：
10.1083/jcb.127.1.203
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发表时间：
1994-10
影响因子：
7.8
通讯作者：
Stachowiak, E K
中科院分区：
文献类型：
--
作者：
Stachowiak, M K;Moffett, J;Joy, A;Puchacz, E;Florkiewicz, R;Stachowiak, E K
碱性成纤维细胞生长因子 (bFGF) 是一种有效的有丝分裂/神经营养因子，控制多种神经细胞的发育和可塑性。在肾上腺嗜铬细胞中，bFGF 蛋白的出现与功能性神经支配的建立同时发生，表明是由跨突触信号诱导的。在培养的牛肾上腺髓质细胞中，蛋白质印迹分析显示胞质和核部分中存在 18、23 和 24 kD bFGF 亚型。刺激乙酰胆碱烟碱受体或激素血管紧张素 II 受体或用毛喉素直接刺激腺苷酸环化酶或用 PMA 直接刺激蛋白激酶 C (PKC) 会增加所有 bFGF 同工型的含量。细胞内 bFGF 水平的增加并未导致培养基中检测到 bFGF 蛋白的存在。相反，bFGF 蛋白在细胞质或细胞核中积累，具体取决于 PKC 或 cAMP 途径是否被激活。放线菌酮或反义 bFGF 寡核苷酸可以阻止毛喉素诱导的 bFGF 长期核积累，并且还伴随着 bFGF mRNA 的增加。我们使用含有人bFGF启动子的荧光素酶报告质粒来表明bFGF的诱导是由bFGF基因的转录激活引起的，并且是由位于其转录起始位点上游的调控序列介导的。 forskolin 和 PMA 对 bFGF 基因表达的刺激是协同的，并且是通过不同的启动子区域介导的。结果表明 cAMP 和 PKC 的刺激是通过新的顺式元件介导的。 bFGF 蛋白含量的调节还涉及转录后机制，因为各个 bFGF 同工型水平的变化根据细胞是否用卡巴胆碱、血管紧张素 II、毛喉素或 PMA 处理而有所不同。本研究表明bFGF是一种内分泌细胞质核因子，其表达受到跨突触和激素刺激的调节，并且可能作为基因组对传入刺激反应的直接介质。
Basic fibroblast growth factor (bFGF), a potent mitogenic/neurotrophic factor, controls the development and plasticity of many types of neural cells. In adrenal chromaffin cells, the appearance of bFGF protein coincided with the establishment of functional innervation, suggesting induction by trans-synaptic signals. In cultured bovine adrenal medullary cells Western blot analysis revealed 18-, 23-, and 24-kD bFGF isoforms in the cytosolic and nuclear fractions. Stimulation of acetylcholine nicotinic receptors or hormonal angiotensin II receptors or the direct stimulation of adenylate cyclase with forskolin or protein kinase C (PKC) with PMA increased the content of all bFGF isoforms. Increases in the levels of intracellular bFGF did not result in detectable presence of bFGF proteins in culture medium. Instead, bFGF proteins accumulated in the cytoplasm or the nucleus depending on whether PKC or cAMP pathways were activated. The long-term nuclear forskolin-induced accumulation of bFGF was prevented by cycloheximide or by antisense bFGF oligonucleotide and was also accompanied by an increase in bFGF mRNA. We used luciferase reporter plasmids containing the human bFGF promoter to show that the induction of bFGF resulted from transcriptional activation of the bFGF gene and was mediated by regulatory sequences located upstream from its transcription start site. Stimulation of bFGF gene expression by forskolin and PMA was synergistic and was mediated through different promoter regions. The results suggest that stimulation by cAMP and PKC is mediated through novel cis elements. The regulation of bFGF protein content also involves posttranscriptional mechanisms since changes in the levels of individual bFGF isoforms were different depending on whether cells were treated with carbachol or angiotensin II, forskolin, or PMA. The present study indicates that bFGF is an intracrine cytoplasmic-nuclear factor, whose expression is regulated by trans-synaptic and hormonal stimuli and which may act as a direct mediator of genomic responses to afferent stimulation.