A Eukaryotic Sensor for Membrane Lipid Saturation.
Mol Cell
; 63(1): 49-59, 2016 07 07.
Article
em En
| MEDLINE
| ID: mdl-27320200
ABSTRACT
Maintaining a fluid bilayer is essential for cell signaling and survival. Lipid saturation is a key factor determining lipid packing and membrane fluidity, and it must be tightly controlled to guarantee organelle function and identity. A dedicated eukaryotic mechanism of lipid saturation sensing, however, remains elusive. Here we show that Mga2, a transcription factor conserved among fungi, acts as a lipid-packing sensor in the ER membrane to control the production of unsaturated fatty acids. Systematic mutagenesis, molecular dynamics simulations, and electron paramagnetic resonance spectroscopy identify a pivotal role of the oligomeric transmembrane helix (TMH) of Mga2 for intra-membrane sensing, and they show that the lipid environment controls the proteolytic activation of Mga2 by stabilizing alternative rotational orientations of the TMH region. This work establishes a eukaryotic strategy of lipid saturation sensing that differs significantly from the analogous bacterial mechanism relying on hydrophobic thickness.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Fatores de Transcrição
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Proteínas de Saccharomyces cerevisiae
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Retículo Endoplasmático
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Ácidos Graxos
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Membranas Intracelulares
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Fluidez de Membrana
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Proteínas de Membrana
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article