Maxwell Steve A, Kochevar Gerald J
Department of Molecular & Cellular Medicine, Room 252, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, USA.
Biochem Biophys Res Commun. 2008 May 2;369(2):308-13. doi: 10.1016/j.bbrc.2008.01.171. Epub 2008 Feb 13.
Proline oxidase (POX) is a p53-induced proapoptotic gene. We investigated whether p53 could bind directly to the POX gene promoter. Chromatin immunoprecipitation (ChIP) assays detected p53 bound to POX upstream gene sequences. In support of the ChIP results, sequence analysis of the POX gene and its 5' flanking sequences revealed a potential p53-binding site, GGGCTTGTCTTCGTGTGACTTCTGTCT, located at 1161 base pairs (bp) upstream of the transcriptional start site. A 711-bp DNA fragment containing the candidate p53-binding site exhibited reporter gene activity that was induced by p53. In contrast, the same DNA region lacking the candidate p53-binding site did not show significant p53-response activity. Electrophoretic mobility shift assay (EMSA) in ACHN renal carcinoma cell nuclear lysates confirmed that p53 could bind to the 711-bp POX DNA fragment. We concluded from these experiments that a p53-binding site is positioned at -1161 to -1188bp upstream of the POX transcriptional start site.
脯氨酸氧化酶（POX）是一种p53诱导的促凋亡基因。我们研究了p53是否能直接结合到POX基因启动子上。染色质免疫沉淀（ChIP）分析检测到p53与POX上游基因序列结合。为支持ChIP结果，对POX基因及其5'侧翼序列的序列分析揭示了一个潜在的p53结合位点GGGCTTGTCTTCGTGTGACTTCTGTCT，位于转录起始位点上游1161个碱基对（bp）处。一个包含候选p53结合位点的711-bp DNA片段表现出由p53诱导的报告基因活性。相反，缺少候选p53结合位点的相同DNA区域未显示出显著的p53反应活性。ACHN肾癌细胞核裂解物中的电泳迁移率变动分析（EMSA）证实p53能结合到711-bp的POX DNA片段上。我们从这些实验得出结论，p53结合位点位于POX转录起始位点上游-1161至-1188bp处。
