Weisinger G, DeCristofaro J D, LaGamma E F
Department of Pediatrics, State University of New York, Stony Brook 11794-8111.
J Biol Chem. 1990 Oct 15;265(29):17389-92.
A major control of gene expression occurs at the level of initiation of RNA transcription. In the nervous system this is reflected in part by 5' end RNA heterogeneity of neural transcripts. We now report the characterization of four preproenkephalin (ppEnk) RNA initiation sites in the rat brain striatum. In the adrenal medulla two ppEnk transcriptional start sites were detected. Moreover, cholinergic induction of ppEnk RNA initiation was observed in the adrenal medulla, but not in the striatum. The converse was true following handling stress. Our observations suggest that selective start site usage and stimulus evoked induction of specific RNA initiation is tissue-specific. We speculate that start site usage and induction may provide separate mechanisms through which neuronal gene expression is controlled in anatomically, as well as functionally distinct neurohumoral structures.
基因表达的主要调控发生在RNA转录起始水平。在神经系统中，这部分反映在神经转录本的5'端RNA异质性上。我们现在报告大鼠脑纹状体中四个前脑啡肽原（ppEnk）RNA起始位点的特征。在肾上腺髓质中检测到两个ppEnk转录起始位点。此外，在肾上腺髓质中观察到ppEnk RNA起始的胆碱能诱导，但在纹状体中未观察到。处理应激后情况相反。我们的观察结果表明，选择性起始位点的使用和刺激诱发的特定RNA起始的诱导是组织特异性的。我们推测，起始位点的使用和诱导可能提供了不同的机制，通过这些机制在解剖学上以及功能上不同的神经体液结构中控制神经元基因表达。
