Pentobarbital-induced Changes in Drosophila Glutathione S-Transferase D21 mRNA Stability (*)
Pentobarbital-induced Changes in Drosophila Glutathione S-Transferase D21 mRNA Stability (*)
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DOI：
10.1074/jbc.270.23.13819
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发表时间：
1995-06
期刊：
影响因子：
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通讯作者：
Amy Tang;C. Tu
中科院分区：
文献类型：
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作者：
Amy Tang;C. Tu
果蝇谷胱甘肽S-转移酶（gstD）基因是一个转录差异的无内含子基因和假基因家族。在对照条件下，gstD 1 mRNA的稳态水平是20倍高于gstD 21 mRNA，尽管较低的转录率的gstD 1基因。GST D1蛋白水平是GST D21蛋白的四倍。gstD 1和gstD 21基因迅速响应戊巴比妥（PB）的mRNA水平的变化在治疗的30分钟内检测。gstD 1和gstD 21的最大诱导导致其各自的mRNA水平升高3倍和20倍。gstD 1 mRNA增加的主要机制似乎是转录激活。然而，gstD 21转录速率的2倍增加不能完全解释gstD 21 mRNA稳态水平的20倍增加。因此，转录后机制也应该是PB增加gstD 21 mRNA的原因。由于gstD 21 mRNA在对照条件下相对不稳定，PB对无内含子gstD 21 mRNA的诱导主要发生在mRNA稳定性增强的水平。PB处理后，成年果蝇的GST D1蛋白水平增加了约2倍，而GST D21水平保持相对不变。因此，PB处理增加gstD 21 mRNA稳定性可能与翻译水平的调节作用相关。
The Drosophila glutathione S-transferase (gstD) genes are a family of divergently transcribed, intronless genes and pseudogenes. Under control conditions, the steady-state level of gstD1 mRNA is 20-fold higher than that of the gstD21 mRNA despite a lower transcription rate of the gstD1 gene. The GST D1 protein level is four times as abundant as the GST D21 protein. The gstD1 and gstD21 genes responded rapidly to pentobarbital (PB) as changes in mRNA levels were detectable within 30 min of treatment. Maximal induction of gstD1 and gstD21 resulted in 3-fold and 20-fold elevation of their respective mRNA levels. The major mechanism for the increase in gstD1 mRNAs appears to be transcriptional activation. The 2-fold increase in the rate of gstD21 transcription, however, cannot fully account for the 20-fold increase in the steady-state level of gstD21 mRNA. Therefore, post-transcriptional mechanism(s) should also be responsible for the increase of gstD21 mRNA by PB. Because the gstD21 mRNA is relatively unstable under control conditions, induction of the intronless gstD21 mRNA by PB occurs mainly at the level of enhanced mRNA stability. The GST D1 protein level in adult Drosophila was increased approximately 2-fold after PB treatment, whereas the GST D21 level remained relatively the same. Thus, an increase in gstD21 mRNA stability by PB treatment is probably coupled to a regulatory effect at the translational level.