Boyd R T
Department of Pharmacology, The Ohio State University College of Medicine, Columbus 43210, USA.
Neurosci Lett. 1996 Apr 19;208(2):73-6. doi: 10.1016/0304-3940(96)12561-1.
The effects of increased cAMP level and reduced protein kinase C activity on transcription of the alpha 3 neuronal nicotinic acetylcholine receptor (nAChR) gene in PC12 cells were examined. Two nAChR alpha 3 transcripts (3.9 and 2.4 kb) are expressed in PC12 cells. When PC12 cells were grown in 2 mu m phorbol 12-myristate 13-acetate (PMA) for 2 days to lower protein kinase C activity, the levels of both transcripts were increased. When PC12 cells were grown in 5 mu m forskolin, the level of the 3.9 kb transcript was increased. We previously constructed clones containing promoter elements located upstream of the alpha 3 gene which allow reporter gene expression in PC12 cells. These constructs were transfected into PC12 cells grown in PMA or forskolin. The increase in alpha 3 transcripts in response to PMA or forskolin was shown to be mediated at least in part at the transcriptional level by elements located within 600 nucleotides of the transcriptional start sites. The promoter constructs were also used to demonstrate that elements needed to restrict the expression of alpha 3 in non-neuronal cells lie near to the 5' end of the alpha 3 gene.
研究了环磷酸腺苷（cAMP）水平升高和蛋白激酶C活性降低对PC12细胞中α3神经元烟碱型乙酰胆碱受体（nAChR）基因转录的影响。PC12细胞中表达两种nAChRα3转录本（3.9 kb和2.4 kb）。当PC12细胞在2 μM佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）中培养2天以降低蛋白激酶C活性时，两种转录本的水平均升高。当PC12细胞在5 μM福斯高林中培养时，3.9 kb转录本的水平升高。我们之前构建了包含位于α3基因上游的启动子元件的克隆，这些元件可使报告基因在PC12细胞中表达。将这些构建体转染到在PMA或福斯高林中培养的PC12细胞中。结果表明，α3转录本对PMA或福斯高林的增加至少部分是由转录起始位点600个核苷酸内的元件在转录水平介导的。启动子构建体还用于证明在非神经元细胞中限制α3表达所需的元件位于α3基因的5'端附近。
