Identification of a novel functional deletion variant in the 5'-UTR of the DJ-1 gene.

Full Abstract

BACKGROUND: DJ-1 forms part of the neuronal cellular defence mechanism against oxidative insults, due to its ability to undergo self-oxidation. Oxidative stress has been implicated in the pathogenesis of central nervous system damage in different neurodegenerative disorders including Alzheimer's disease and Parkinson's disease (PD). Various mutations in the DJ-1 (PARK7) gene have been shown to cause the autosomal recessive form of PD. In the present study South African PD patients were screened for mutations in DJ-1 and we aimed to investigate the functional significance of a novel 16 bp deletion variant identified in one patient. METHODS: The possible effect of the deletion on promoter activity was investigated using a Dual-Luciferase Reporter assay. The DJ-1 5'-UTR region containing the sequence flanking the 16 bp deletion was cloned into a pGL4.10-Basic luciferase-reporter vector and transfected into HEK293 and BE(2)-M17 neuroblastoma cells. Promoter activity under hydrogen peroxide-induced oxidative stress conditions was also investigated. Computational (in silico) cis-regulatory analysis of DJ-1 promoter sequence was performed using the transcription factor-binding site database, TRANSFAC via the PATCH and rVISTA platforms. RESULTS: A novel 16 bp deletion variant (g.-6_+10del) was identified in DJ-1 which spans the transcription start site and is situated 93 bp 3' from a Sp1 site. The deletion caused a reduction in luciferase activity of approximately 47% in HEK293 cells and 60% in BE(2)-M17 cells compared to the wild-type (P < 0.0001), indicating the importance of the 16 bp sequence in transcription regulation. The activity of both constructs was up-regulated during oxidative stress. Bioinformatic analysis revealed putative binding sites for three transcription factors AhR, ARNT, HIF-1 within the 16 bp sequence. The frequency of the g.-6_+10del variant was determined to be 0.7% in South African PD patients (2 heterozygotes in 148 individuals). CONCLUSION: This is the first report of a functional DJ-1 promoter variant, which has the potential to influence transcript stability or translation efficiency. Further work is necessary to determine the extent to which the g.-6_+10del variant affects the normal function of the DJ-1 promoter and whether this variant confers a risk for PD.

Author information

Author/s: Keyser, Rowena J (RJ); van der Merwe, Lize (L); Venter, Mauritz (M); Kinnear, Craig (C); Warnich, Louise (L); Carr, Jonathan (J); Bardien, Soraya (S);

Affiliation: Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, University of Stellenbosch, Cape Town, 8001, South Africa. rowenak(-atsign-)sun.ac.za

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: BMC medical genetics (BMC Med Genet), published in England. (Language: eng)

Reference: 2009-; vol 10 (issue ) : pp 105

Dates: Created 2009/10/27; Completed 2009/10/28; Revised 2009/10/28;

PMID: 19825160, status: MEDLINE (last retrieval date: 10/29/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Humans
Intracellular Signaling Peptides and Proteins - genetics
Male
Middle Aged
Oncogene Proteins - genetics
Parkinson Disease - genetics
Polymorphism, Restriction Fragment Length
Promoter Regions, Genetic
Transcription, Genetic
Young Adult

Associated Chemicals: 5' Untranslated Regions (0) ; Intracellular Signaling Peptides and Proteins (0) ; Oncogene Proteins (0) ; PARK7 protein, human (0)

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