BECN2 interacts with ATG14 through a metastable coiled-coil to mediate autophagy.
Protein Sci
; 26(5): 972-984, 2017 05.
Article
em En
| MEDLINE
| ID: mdl-28218432
ABSTRACT
ATG14 binding to BECN/Beclin homologs is essential for autophagy, a critical catabolic homeostasis pathway. Here, we show that the α-helical, coiled-coil domain (CCD) of BECN2, a recently identified mammalian BECN1 paralog, forms an antiparallel, curved homodimer with seven pairs of nonideal packing interactions, while the BECN2 CCD and ATG14 CCD form a parallel, curved heterodimer stabilized by multiple, conserved polar interactions. Compared to BECN1, the BECN2 CCD forms a weaker homodimer, but binds more tightly to the ATG14 CCD. Mutation of nonideal BECN2 interface residues to more ideal pairs improves homodimer self-association and thermal stability. Unlike BECN1, all BECN2 CCD mutants bind ATG14, although more weakly than wild type. Thus, polar BECN2 CCD interface residues result in a metastable homodimer, facilitating dissociation, but enable better interactions with polar ATG14 residues stabilizing the BECN2ATG14 heterodimer. These structure-based mechanistic differences in BECN1 and BECN2 homodimerization and heterodimerization likely dictate competitive ATG14 recruitment.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Autofagia
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Proteínas Adaptadoras de Transporte Vesicular
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Peptídeos e Proteínas de Sinalização Intracelular
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Multimerização Proteica
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Proteínas Relacionadas à Autofagia
Limite:
Humans
Idioma:
En
Revista:
Protein Sci
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2017
Tipo de documento:
Article