Multiple splicing defects caused by hERG splice site mutation 2592+1G>A associated with long QT syndrome.
Am J Physiol Heart Circ Physiol
; 300(1): H312-8, 2011 Jan.
Article
en En
| MEDLINE
| ID: mdl-21057041
Long QT syndrome type 2 (LQT2) is caused by mutations in the human ether-a-go-go-related gene (hERG). Cryptic splice site activation in hERG has recently been identified as a novel pathogenic mechanism of LQT2. In this report, we characterize a hERG splice site mutation, 2592+1G>A, which occurs at the 5' splice site of intron 10. Reverse transcription-PCR analyses using hERG minigenes transfected into human embryonic kidney-293 cells and HL-1 cardiomyocytes revealed that the 2592+1G>A mutation disrupted normal splicing and caused multiple splicing defects: the activation of cryptic splice sites within exon 10 and intron 10 and complete intron 10 retention. We performed functional and biochemical analyses of the major splice product, hERGΔ24, in which 24 amino acids within the cyclic nucleotide binding domain of the hERG channel COOH-terminus is deleted. Patch-clamp experiments revealed that the splice mutant did not generate hERG current. Western blot and immunostaining studies showed that mutant channels did not traffic to the cell surface. Coexpression of wild-type hERG and hERGΔ24 resulted in significant dominant-negative suppression of hERG current via the intracellular retention of the wild-type channels. Our results demonstrate that 2592+1G>A causes multiple splicing defects, consistent with the pathogenic mechanisms of long QT syndrome.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Síndrome de QT Prolongado
/
Empalme del ARN
/
Canales de Potasio Éter-A-Go-Go
/
Mutación
Tipo de estudio:
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
Am J Physiol Heart Circ Physiol
Asunto de la revista:
CARDIOLOGIA
/
FISIOLOGIA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos