Unravelling the orientation of the inositol-biphosphate ring and its dependence on phosphatidylinositol 4,5-bisphosphate cluster formation in model membranes

Hypothesis Inositol phospholipids are well known to form clusters in the cytoplasmic leaflet of the plasma membrane that are responsible for the interaction and recruitment of proteins involved in key biological processes like endocytosis, ion channel activation and secondary messenger production. A...

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Detalles Bibliográficos
Autores: Santamaria, Andreas, Carrascosa-Tejedor, Javier, Guzmán Solís, Eduardo, Zaccai, Nathan R., Maestro, Armando
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/95202
Acceso en línea:https://hdl.handle.net/20.500.14352/95202
Access Level:acceso abierto
Palabra clave:544
Química física (Química)
2307 Química Física
2210 Química Física
2299 Otras Especialidades Físicas
Descripción
Sumario:Hypothesis Inositol phospholipids are well known to form clusters in the cytoplasmic leaflet of the plasma membrane that are responsible for the interaction and recruitment of proteins involved in key biological processes like endocytosis, ion channel activation and secondary messenger production. Although their phosphorylated inositol ring headgroup plays an important role in protein binding, its orientation with respect to the plane of the membrane and its lateral packing density has not been previously described experimentally. Experiments Here, we study phosphatidylinositol 4,5-bisphosphate (PIP2) planar model membranes in the form of Langmuir monolayers by surface pressure-area isotherms, Brewster angle microscopy and neutron reflectometry to elucidate the relation between lateral (in-plane) and perpendicular (out-of-plane) molecular organization of PIP2. Findings Different surface areas were explored through monolayer compression, allowing us to correlate the formation of transient PIP2 clusters with the change in orientation of the inositol-biphosphate headgroup, which was experimentally determined by neutron reflectometry.