Artículo
The single transmembrane segment of minimal sensor DesK senses temperature via a membrane-thickness caliper
Fecha de publicación:
11/2016
Editorial:
American Society for Microbiology
Revista:
Journal of Bacteriology
ISSN:
0021-9193
e-ISSN:
1098-5530
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Thermosensors detect temperature changes and trigger cellular responses crucial for survival at different temperatures. The thermosensor DesK is a transmembrane (TM) histidine kinase which detects a decrease in temperature through its TM segments (TMS). Here, we address a key issue: how a physical stimulus such as temperature can be converted into a cellular response. We show that the thickness of Bacillus lipid membranes varies with temperature and that such variations can be detected by DesK with great precision. On the basis of genetic studies and measurements of in vitro activity of a DesK construct with a single TMS (minimal sensor DesK [MS-DesK]), reconstituted in liposomes, we propose an interplay mechanism directed by a conserved dyad, phenylalanine 8-lysine 10. This dyad is critical to anchor the only transmembrane segment of the MS-DesK construct to the extracellular water-lipid interphase and is required for the transmembrane segment of MS-DesK to function as a caliper for precise measurement of membrane thickness. The data suggest that positively charged lysine 10, which is located in the hydrophobic core of the membrane but is close to the water-lipid interface, pulls the transmembrane region toward the water phase to localize its charge at the interface. Nevertheless, the hydrophobic residue phenylalanine 8, located at the N-terminal extreme of the TMS, has a strong tendency to remain in the lipid phase, impairing access of lysine 10 to the water phase. The outcome of this interplay is a fine-tuned sensitivity to membrane thickness that elicits conformational changes that favor different signaling states of the protein.
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Licencia
Identificadores
Colecciones
Articulos(CCT - ROSARIO)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - ROSARIO
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - ROSARIO
Articulos(CIQUIBIC)
Articulos de CENTRO DE INVEST.EN QCA.BIOL.DE CORDOBA (P)
Articulos de CENTRO DE INVEST.EN QCA.BIOL.DE CORDOBA (P)
Citación
Inda, María Eugenia; Oliveira, Rafael Gustavo; de Mendoza, Diego; Cybulski, Larisa Estefania; The single transmembrane segment of minimal sensor DesK senses temperature via a membrane-thickness caliper; American Society for Microbiology; Journal of Bacteriology; 198; 21; 11-2016; 2945-2954
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