A transcriptional regulatory element critical for CHRNB4 promoter activity in vivo
Brudnick Neuropsychiatric Research Institute, Department of Psychiatry; Graduate School of Biomedical Sciences, Interdisciplinary Graduate Program; Tapper Lab; Gardner Lab
Neuroscience and Neurobiology
Genome-wide association studies have underscored the importance of the clustered neuronal nicotinic acetylcholine receptor (nAChR) subunit genes with respect to nicotine dependence as well as lung cancer susceptibility. CHRNB4, which encodes the nAChR beta4 subunit, plays a major role in the molecular mechanisms that govern nicotine withdrawal. Thus, elucidating how expression of the beta4 gene is regulated is critical for understanding the pathophysiology of nicotine addiction. We previously identified a CA box regulatory element, (5'-CCACCCCT-3') critical for beta4 promoter activity in vitro. We further demonstrated that a 2.3-kb fragment of the beta4 promoter region containing the 5'-CCACCCCT-3' regulatory element in the beta4 gene promoter (CA box) is capable of directing cell-type specific expression of a reporter gene to a myriad of brain regions that endogenously express the beta4 gene. To test the hypothesis that the CA box is critical for beta4 promoter activity in vivo, transgenic animals expressing a mutant form of the beta4 promoter were generated. Reporter gene expression was not detected in any tissue or cell type at embryonic day 18.5 (ED 18.5). Similarly, we observed drastically reduced reporter gene expression at postnatal day 30 (PD30) when compared to wild type (WT) transgenic animals. Finally, we demonstrated that CA box mutation results in decreased interaction of the transcription factor Sp1 with the mutant beta4 promoter. Taken together these results demonstrate that the CA box is critical for beta4 promoter activity in vivo.
nicotinic acetylcholine receptors, CHRNB4, Sp1, CACCC, transgenic mice
DOI of Published Version
Neuroscience. 2010 Nov 10;170(4):1056-64. doi: 10.1016/j.neuroscience.2010.08.007. Epub 2010 Aug 6. Link to article on publisher's site
Scofield, Michael D.; Tapper, Andrew R.; and Gardner, Paul D., "A transcriptional regulatory element critical for CHRNB4 promoter activity in vivo" (2010). University of Massachusetts Medical School Faculty Publications. 1466.