Cholesterol sensing by the ABCG1 lipid transporter: Requirement of a CRAC motif in the final transmembrane domain.
Biochim Biophys Acta
; 1851(7): 956-64, 2015 Jul.
Article
em En
| MEDLINE
| ID: mdl-25732853
ABSTRACT
The ATP-binding cassette (ABC) transporter, ABCG1, is a lipid exporter involved in removal of cholesterol from cells that has been investigated for its role in foam cells formation and atherosclerosis. The mechanism by which ABC lipid transporters bind and recognise their substrates is currently unknown. In this study, we identify a critical region in the final transmembrane domain of ABCG1, which is essential for its export function and stabilisation by cholesterol, a post-translational regulatory mechanism that we have recently identified as dependent on protein ubiquitination. This transmembrane region contains several Cholesterol Recognition/interaction Amino acid Consensus (CRAC) motifs, and its inverse CARC motifs. Mutational analyses identify one CRAC motif in particular with Y667 at its core, that is especially important for transport activity to HDL as well as stability of the protein in the presence of cholesterol. In addition, we present a model of how cholesterol docks to this CRAC motif in an energetically favourable manner. This study identifies for the first time how ABCG1 can interact with cholesterol via a functional CRAC domain, which provides the first insight into the substrate-transporter interaction of an ABC lipid exporter.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Colesterol
/
Transportadores de Cassetes de Ligação de ATP
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Domínios e Motivos de Interação entre Proteínas
Limite:
Animals
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Humans
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Austrália