The scaffold protein EPG-7 links cargo-receptor complexes with the autophagic assembly machinery.
J Cell Biol
; 201(1): 113-29, 2013 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-23530068
ABSTRACT
The mechanism by which protein aggregates are selectively degraded by autophagy is poorly understood. Previous studies show that a family of Atg8-interacting proteins function as receptors linking specific cargoes to the autophagic machinery. Here we demonstrate that during Caenorhabditis elegans embryogenesis, epg-7 functions as a scaffold protein mediating autophagic degradation of several protein aggregates, including aggregates of the p62 homologue SQST-1, but has little effect on other autophagy-regulated processes. EPG-7 self-oligomerizes and is degraded by autophagy independently of SQST-1. SQST-1 directly interacts with EPG-7 and colocalizes with EPG-7 aggregates in autophagy mutants. Mutations in epg-7 impair association of SQST-1 aggregates with LGG-1/Atg8 puncta. EPG-7 interacts with multiple ATG proteins and colocalizes with ATG-9 puncta in various autophagy mutants. Unlike core autophagy genes, epg-7 is dispensable for starvation-induced autophagic degradation of substrate aggregates. Our results indicate that under physiological conditions a scaffold protein endows cargo specificity and also elevates degradation efficiency by linking the cargo-receptor complex with the autophagic machinery.
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Base de dados:
MEDLINE
Assunto principal:
Autofagia
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Caenorhabditis elegans
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Proteínas de Caenorhabditis elegans
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Desenvolvimento Embrionário
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Embrião não Mamífero
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Multimerização Proteica
Limite:
Animals
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article