Ethanol-induced translocation of cAMP-dependent protein kinase to the nucleus - Mechanism and functional consequences
Ethanol-induced translocation of cAMP-dependent protein kinase to the nucleus - Mechanism and functional consequences
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DOI：
10.1074/jbc.274.38.26985
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发表时间：
1999-09-17
影响因子：
4.8
通讯作者：
Gordon, AS
中科院分区：
文献类型：
--
作者：
Constantinescu, A;Diamond, I;Gordon, AS
在NG108-15细胞中，乙醇诱导camp依赖性蛋白激酶（PKA）的催化亚基（C α）从高尔基区转移到细胞核。乙醇还诱导PKA的RII β调控亚基向细胞核易位；RI和C没有移位。在乙醇处理的细胞中，核PKA活性不再受cAMP的调节。凝胶过滤和免疫沉淀分析证实，乙醇阻断了C α与RII的解离，但不诱导这些亚基的解离。乙醇也降低了PKA抑制剂PKI对C α的抑制作用。用乙醇预孵育C α可降低Leu-Arg-Arg-Ala-Ser-Leu-Gly （Kemptide）和酪蛋白的磷酸化，但对高电荷分子如组蛋白H1或鱼精蛋白的磷酸化没有影响。在乙醇处理的细胞中，camp反应元件结合蛋白（CREB）被C α磷酸化也增加。这种CREB磷酸化的增加被PKA拮抗剂(R-p)- camp和腺苷受体拮抗剂抑制。这些结果表明，乙醇影响一系列事件，允许持续的C α核定位和延长CREB磷酸化。这些事件可能解释了乙醇诱导的camp依赖性基因表达的变化。
Ethanol induces translocation of the catalytic subunit (C alpha) of cAMP-dependent protein kinase (PKA) from the Golgi area to the nucleus in NG108-15 cells. Ethanol also induces translocation of the RII beta regulatory subunit of PKA to the nucleus; RI and C beta are not translocated. Nuclear PKA activity in ethanol-treated cells is no longer regulated by cAMP. Gel filtration and immunoprecipitation analysis confirm that ethanol blocks the dissociation of C alpha with RII but does not induce dissociation of these subunits. Ethanol also reduces inhibition of C alpha by the PKA inhibitor PKI. Pre-incubation of C alpha with ethanol decreases phosphorylation of Leu-Arg-Arg-Ala-Ser-Leu-Gly (Kemptide) and casein but has no effect on the phosphorylation of highly charged molecules such as histone H1 or protamine. cAMP-response element-binding protein (CREB) phosphorylation by C alpha is also increased in ethanol-treated cells. This increase in CREB phosphorylation is inhibited by the PKA antagonist (R-p)-cAMPS and by an adenosine receptor antagonist. These results suggest that ethanol affects a cascade of events allowing for sustained nuclear localization of C alpha and prolonged CREB phosphorylation. These events may account for ethanol-induced changes in cAMP-dependent gene expression.