The Mgr2 subunit of the TIM23 complex regulates membrane insertion of marginal stop-transfer signals in the mitochondrial inner membrane.
FEBS Lett
; 594(6): 1081-1087, 2020 03.
Article
em En
| MEDLINE
| ID: mdl-31764998
ABSTRACT
The TIM23 complex mediates membrane insertion of presequence-containing mitochondrial proteins via a stop-transfer mechanism. Stop-transfer signals consist of hydrophobic transmembrane segments and flanking charges. Mgr2 functions as a lateral gatekeeper of the TIM23 complex. However, it remains elusive which features of stop-transfer signals are discriminated by Mgr2. To determine the effects of Mgr2 on the TIM23-mediated stop-transfer pathway, we measured membrane insertion of model transmembrane segments of varied hydrophobicity and flanking charges in Mgr2-deletion or -overexpression yeast strains. We found that upon deletion of Mgr2, the threshold hydrophobicity for membrane insertion, as well as the requirement for matrix-facing positive charges, is reduced. These results imply that the Mgr2-mediated gatekeeper function is important for controlling membrane sorting of marginal stop-transfer signals.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Membrana Transportadoras
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Saccharomyces cerevisiae
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Proteínas de Saccharomyces cerevisiae
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Membranas Mitocondriais
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Proteínas de Membrana
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Mitocôndrias
Idioma:
En
Revista:
FEBS Lett
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Coréia do Sul