Journal
CARDIOVASCULAR RESEARCH
Volume 61, Issue 1, Pages 56-65Publisher
OXFORD UNIV PRESS
DOI: 10.1016/j.cardiores.2003.09.030
Keywords
ion channels; arrhythmia (mechanism); gene polymorphisms
Categories
Funding
- NATIONAL HEART, LUNG, AND BLOOD INSTITUTE [U19HL065962, U01HL065962, P01HL046681] Funding Source: NIH RePORTER
- NHLBI NIH HHS [HL46681, HL65962] Funding Source: Medline
Ask authors/readers for more resources
Objective: Despite the primacy of the sodium current in cardiac electrophysiology and evidence that decreased sodium current is arrhythmogenic in humans, little is known about transcriptional regulation of the underlying gene, SCN5A. Methods: We have cloned a 2.7 kb segment of 5'-flanking region of SCN5A and identified multiple transcription initiation sites by primer extension and RNase protection. Transient transfection assays in neonatal mouse myocytes and in Chinese Hamster Ovary (CHO) cells were employed to identify promoter activities. PCR-single-stranded conformational polymorphism (SSCP) analysis was used to screen DNA variants in the promoter region. Results: The fragment includes >2 kb of upstream sequence, the 173-bp non-coding exon 1, and a portion of the 16-kb intron 1; the region is highly GC-rich and TATA-less. Transient transfection assays in neonatal mouse myocytes and in CHO cells identified (1) a core promoter in the -261/+140 segment, (2) regions conferring similar to3-fold decreases from core promoter activity in the 5' upstream region (-261/-454 and -1020/-2109), and similar to3-fold increases in intron 1 (+255/+410 and +539/+613), and (3) a very strong negative regulatory region between +613 and +754 in intron 1. A core promoter polymorphism, present in 6/142 (4%) of normal alleles screened, increased reporter activity similar to50% in myocytes but not in CHO cells. Conclusion: The SCN5A promoter includes multiple positive and negative cis-acting elements extending into intron 1. A common polymorphism in this region modulates channel expression in vitro. (C) 2003 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available