Depolarization causes the formation of a ternary complex between GlialCAM, MLC1 and ClC-2 in astrocytes: implications in megalencephalic leukoencephalopathy.
Hum Mol Genet
; 26(13): 2436-2450, 2017 07 01.
Article
em En
| MEDLINE
| ID: mdl-28398517
ABSTRACT
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare type of leukodystrophy caused by mutations in either MLC1 or GLIALCAM. GlialCAM is necessary for the correct targeting of MLC1, but also for the targeting of the Cl- channel ClC-2. Furthermore, GlialCAM modifies ClC-2 functional properties in vitro. However, in vivo studies in GlialCAM-/- mice have shown that the modification of ClC-2 activity only occurs in oligodendrocytes, despite GlialCAM and ClC-2 being expressed in astrocytes. Thus, the relationship between GlialCAM, MLC1 and ClC-2 in astrocytes is unknown. Here, we show that GlialCAM, ClC-2 and MLC1 can form a ternary complex in cultured astrocytes, but only under depolarizing conditions. We also provide biochemical evidences that this ternary complex exists in vivo. The formation of this complex changes ClC-2 localization in the membrane and its functional properties. ClC-2 association with GlialCAM/MLC1 depends on calcium flux through L-type calcium channels and activation of calcium-dependent calpain proteases. Based on these studies, we propose that the chloride influx mediated by GlialCAM/MLC1/ClC-2 in astrocytes may be needed to compensate an excess of potassium, as occurs in conditions of high neuronal activity. We suggest that a defect in this compensation may contribute to the pathogenesis of MLC disease.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Moléculas de Adesão Celular Neurônio-Glia
/
Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central
/
Cistos
/
Proteínas de Membrana
/
Proteínas do Tecido Nervoso
Tipo de estudo:
Etiology_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Hum Mol Genet
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA MEDICA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Espanha