Activation of AMP-activated protein kinase stimulates the nuclear localization of glyceraldehyde 3-phosphate dehydrogenase in human diploid fibroblasts
Activation of AMP-activated protein kinase stimulates the nuclear localization of glyceraldehyde 3-phosphate dehydrogenase in human diploid fibroblasts
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DOI：
10.3858/emm.2010.42.4.025
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发表时间：
2010-04-30
影响因子：
12.8
通讯作者：
Yeo, Eui-Ju
中科院分区：
文献类型：
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作者：
Kwon, Hyun Jin;Rhim, Ji Heon;Yeo, Eui-Ju
除了众所周知的糖酵解活性外，GAPDH 还具有多种功能，例如核 RNA 输出、DNA 复制和修复以及细胞凋亡。这种功能多样性取决于其细胞内定位。在这项研究中，我们使用免疫染色的人二倍体成纤维细胞（HDF）的共聚焦激光扫描显微镜探索了参与 GAPDH 核转位的信号转导途径。当与10% FBS一起培养时，GAPDH主要存在于细胞质中。在无血清培养基 (SFM) 中培养细胞的血清消耗导致 GAPDH 在细胞核中逐渐积累，并且通过重新添加血清或生长因子（例如 PDGF 和溶血磷脂酸）可逆转这种细胞核积累。重新添加血清或生长因子诱导的核输出被 LY 294002 和 SH-5（分别是磷酸肌醇 3 激酶 (PI3K) 和 Akt/蛋白激酶 B 的抑制剂）阻止，表明 PI3K 信号通路参与了 GAPDH 的核输出。此外，5-氨基咪唑-4-甲酰胺-1-β-D-呋喃核苷 (AICAR) 是 AMP 激活蛋白激酶 (AMPK) 的激活剂，可刺激 GAPDH 的核转位并阻止血清和生长因子诱导的 GAPDH 输出。化合物 C 抑制 AMPK 或 siRNA 处理消除 AMPK 部分阻止了 SFM 和 AICAR 诱导的 GAPDH 核转位。我们的数据表明，GAPDH 的核转位可能受到主要作为核输出信号的 PI3K 信号通路和作为核输入信号的 AMPK 信号通路的调节。
In addition to its well-known glycolytic activity, GAPDH displays multiple functions, such as nuclear RNA export, DNA replication and repair, and apoptotic cell death. This functional diversity depends on its intracellular localization. In this study, we explored the signal transduction pathways involved in the nuclear translocation of GAPDH using confocal laser scanning microscopy of immunostained human diploid fibroblasts (HDFs). GAPDH was present mainly in the cytoplasm when cultured with 10% FBS. Serum depletion by culturing cells in a serum-free medium (SFM) led to a gradual accumulation of GAPDH in the nucleus, and this nuclear accumulation was reversed by the re-addition of serum or growth factors, such as PDGF and lysophosphatidic acid. The nuclear export induced by the re-addition of serum or growth factors was prevented by LY 294002 and SH-5, inhibitors of phosphoinositide 3-kinase (PI3K) and Akt/protein kinase B, respectively, suggesting an involvement of the PI3K signaling pathway in the nuclear export of GAPDH. In addition, 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), an activator of AMP-activated protein kinase (AMPK), stimulated the nuclear translocation of GAPDH and prevented serum- and growth factor-induced GAPDH export. AMPK inhibition by compound C or AMPK depletion by siRNA treatment partially prevented SFM- and AICAR-induced nuclear translocation of GAPDH. Our data suggest that the nuclear translocation of GAPDH might be regulated by the PI3K signaling pathway acting mainly as a nuclear export signal and the AMPK signaling pathway acting as a nuclear import signal.