Regulated exocytosis: renal aquaporin-2 3D vesicular network organization and association with F-actin.
Am J Physiol Cell Physiol
; 321(6): C1060-C1069, 2021 12 01.
Article
em En
| MEDLINE
| ID: mdl-34432538
Regulated vesicle exocytosis is a key response to extracellular stimuli in diverse physiological processes, including hormone regulated short-term urine concentration. In the renal collecting duct, the water channel aquaporin-2 (AQP2) localizes to the apical plasma membrane as well as to small, subapical vesicles. In response to stimulation with the antidiuretic hormone, arginine vasopressin, aquaporin-2-containing vesicles fuse with the plasma membrane, which increases collecting duct water reabsorption and thus, urine concentration. The nanoscale size of these vesicles has limited analysis of their three-dimensional (3D) organization. Using a cell system combined with 3D superresolution microscopy, we provide the first direct analysis of the 3D network of aquaporin-2-containing exocytic vesicles in a cell culture system. We show that aquaporin-2 vesicles are 43 ± 3 nm in diameter, a size similar to synaptic vesicles, and that one fraction of AQP2 vesicles localized with the subcortical F-actin layer and the other localized in between the F-actin layer and the plasma membrane. Aquaporin-2 vesicles associated with F-actin and this association were enhanced in a serine 256 phospho-mimic of aquaporin-2, whose phosphorylation is a key event in antidiuretic hormone-mediated aquaporin-2 vesicle exocytosis.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Membrana Celular
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Actinas
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Aquaporina 2
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Exocitose
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Túbulos Renais Coletores
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol Cell Physiol
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Dinamarca