Alkaline-sensitive two-pore domain potassium channels form functional heteromers in pancreatic β-cells - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Biological Chemistry Année : 2022

Alkaline-sensitive two-pore domain potassium channels form functional heteromers in pancreatic β-cells

Résumé

Two-pore domain K+ channels (K2P channels), active as dimers, produce inhibitory currents regulated by a variety of stimuli. Among them, TWIK1-related alkalinization-activated K+ channel 1 (TALK1), TWIK1-related alkalinization-activated K+ channel 2 (TALK2), and TWIK1-related acid-sensitive K+ channel 2 (TASK2) form a subfamily of structurally related K2P channels stimulated by extracellular alkalosis. The human genes encoding these proteins are clustered at chromosomal region 6p21 and coexpressed in multiple tissues, including the pancreas. The question whether these channels form functional heteromers remained open. By analyzing single-cell transcriptomic data, we show that these channels are coexpressed in insulin-secreting pancreatic β-cells. Using in situ proximity ligation assay and electrophysiology, we show that they form functional heterodimers both upon heterologous expression and under native conditions in human pancreatic β-cells. We demonstrate that heteromerization of TALK2 with TALK1 or with TASK2 endows TALK2 with sensitivity to extracellular alkalosis in the physiological range. We further show that the association of TASK2 with TALK1 and TALK2 increases their unitary conductance. These results provide a new example of heteromerization in the K2P channel family expanding the range of the potential physiological and pathophysiological roles of TALK1/TALK2/TASK2 channels, not only in insulin-secreting cells but also in the many other tissues in which they are coexpressed.
Fichier principal
Vignette du fichier
p33-Khoubza-2022-JBC.pdf (2.23 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03812902 , version 1 (13-10-2022)

Identifiants

Citer

Lamyaa Khoubza, Nicolas Gilbert, Eun-Jin Kim, Franck Chatelain, Sylvain Feliciangeli, et al.. Alkaline-sensitive two-pore domain potassium channels form functional heteromers in pancreatic β-cells. Journal of Biological Chemistry, 2022, 298 (10), pp.102447. ⟨10.1016/j.jbc.2022.102447⟩. ⟨hal-03812902⟩
13 Consultations
10 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More