TASK channels: channelopathies, trafficking, and receptor-mediated inhibition.
Pflugers Arch
; 472(7): 911-922, 2020 07.
Article
em En
| MEDLINE
| ID: mdl-32472332
ABSTRACT
TWIK-related acid-sensitive K+ (TASK) channels contribute to the resting membrane potential in various kinds of cells, such as brain neurons, smooth muscle cells, and endocrine cells. Loss-of-function mutations at multiple sites in the KCNK3 gene encoding for TASK1 channels are one of the causes of pulmonary arterial hypertension in humans, whereas a mutation at only one site is reported for TASK3 channels, resulting in a syndrome of mental retardation, hypotonia, and facial dysmorphism. TASK channels are subject to regulation by G protein-coupled receptors (GPCRs). Two mechanisms have been proposed for the GPCR-mediated inhibition of TASK channels a change in gating and channel endocytosis. The most feasible mechanism for altered gating is diacylglycerol binding to a site in the C-terminus, which is shared by TASK1 and TASK3. The inhibition of channel function by endocytosis requires the presence of a tyrosine residue subjected to phosphorylation by the non-receptor tyrosine kinase Src and a dileucine motif in the C-terminus of TASK1. Therefore, homomeric TASK1 and heteromeric TASK1-TASK3 channels, but not homomeric TASK3, are internalized by GPCR stimulation. Tyrosine phosphorylation by Src is expected to result in a conformational change in the C-terminus, allowing for AP-2, an adaptor protein for clathrin, to bind to the dileucine motif. It is likely that a raft membrane domain is a platform where TASK1 is located and the signaling molecules protein kinase C, Pyk2, and Src are recruited in sequence in response to GPCR stimulation.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transporte Proteico
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Canais de Potássio de Domínios Poros em Tandem
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Canalopatias
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Proteínas do Tecido Nervoso
Limite:
Animals
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Humans
Idioma:
En
Revista:
Pflugers Arch
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Japão
País de publicação:
ALEMANHA
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ALEMANIA
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DE
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DEUSTCHLAND
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GERMANY