Ets‐1/ Elk‐1 is a critical mediator of dipeptidyl‐peptidase III transcription in human glioblastoma cells

• Published in: The FEBS journal Vol. 277; no. 8; pp. 1861 - 1875
• Main Authors: Shukla, Abhay A., Jain, Misti, Chauhan, Shyam S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2010
• Subjects: 5' Flanking Region; 5′‐RACE; Base Sequence; Binding Sites; Biochemistry; Cancer; Cellular biology; Cloning, Molecular; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases - genetics; DNA - genetics; DNA - metabolism; electrophoretic mobility shift assays; ets-Domain Protein Elk-1 - genetics; ets-Domain Protein Elk-1 - metabolism; Gene expression; Glioblastoma - genetics; Histology; Humans; Molecular Sequence Data; Mutation; promoter; Promoter Regions, Genetic; Protein Binding; Proto-Oncogene Protein c-ets-1 - genetics; Proto-Oncogene Protein c-ets-1 - metabolism; Sequence Deletion; site‐directed mutagenesis; transcription factors; Transcription, Genetic
• ISSN: 1742-464X; 1742-4658
• DOI: 10.1111/j.1742-4658.2010.07603.x

Dipetidyl‐petidase III is a metallopeptidase involved in a number of physiological processes and its expression has been reported to increase with the histological aggressiveness of human ovarian primary carcinomas. Because no information regarding the regulation of its expression was available, experiments were designed to clone, define and characterize the promoter region of the human dipeptidyl‐peptidase III (DPP‐III) gene. In this study, we cloned a 1038 bp 5′‐flanking DNA fragment of the human DPP‐III gene for the first time and demonstrated strong promoter activity in this region. Deletion analysis revealed that as few as 45 nucleotides proximal to the transcription start site retained ∼ 40% of the activity of the full‐length promoter. This promoter lacked the TATA box but contained multiple GC boxes and a single CAAT box. Similarly, two Ets‐1/Elk‐1‐binding motifs are present in the first 25 nucleotides from the transcription start site. Binding of Ets‐1/Elk‐1 proteins to these motifs was visualized by electrophoretic mobility shift and chromatin immunoprecipitation assays. Mutations of these binding sites abolished not only binding of the Ets protein, but also the intrinsic promoter activity. Increased DNA‐binding activity of Ets‐1/Elk‐1 by v‐Ha‐ras also augmented the mRNA level and promoter activity of this gene. Similarly, co‐transfection of DPP‐III promoter–reporter constructs with Ets‐1 expression vector led to a significant increase in promoter activity. From these results, we conclude that Ets‐1/Elk‐1 plays a critical role in transcription of the human DPP‐III gene.