The histidine-loop is essential for transport activity of human MDR3. A novel mutation of MDR3 in a patient with progressive familial intrahepatic cholestasis type 3.
Gene
; 506(1): 141-5, 2012 Sep 10.
Article
en En
| MEDLINE
| ID: mdl-22766396
Experimental evidence has been provided that a histidine-loop within the nucleotide binding domain of ABC transporter is essential for efficient function of this class of transporter proteins. Here we report the first patient with a mutation of the putative histidine-loop of a human ABC transporter, the multi drug resistance protein 3 (MDR3). The patient presented at the age of 4 years with a history of severe pruritus, elevated serum gamma-glutamyltransferase and bile acid levels since several years suggesting the diagnosis of progressive familial intrahepatic cholestasis type 3 (PFIC-3) due to defects in MDR3. Liver biopsy demonstrated an apparently normal MDR3 expression, however, genetic analysis revealed a novel homozygous mutation in the ABCB4 gene (c.3691C>T) in the patient. This mutation was associated with a change of histidine to tyrosine at amino acid position 1231 of MDR3 (p.H1231Y). As shown by sequence alignment, this amino acid corresponds to the highly conserved histidine of the "H-loop", which is critical for ATP-hydrolysis, suggesting an essential role of histidine 1231 of human MDR3.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Colestasis Intrahepática
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Subfamilia B de Transportador de Casetes de Unión a ATP
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Mutación Missense
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Gene
Año:
2012
Tipo del documento:
Article