The sulphonylurea receptor confers diazoxide sensitivity on the inwardly rectifying K+ channel Kir6.1 expressed in human embryonic kidney cells.
AUTOR(ES)
Ammälä, C
RESUMO
1. We have examined the effects of diazoxide and intracellular ATP (ATPi) on whole-cell currents in HEK293 cells transfected transiently with the inwardly rectifying K+ channel Kir6.1 (uKATP1) or cotransfected with Kir6.1 and the sulphonylurea receptor (SUR1). 2. Kir6.1 currents were unaffected by the K+ channel opener diazoxide or by dialysis with 0.3 mM ATPi. 3. Kir6.1-SUR1 currents increased in amplitude when cells were dialysed with 0.3 mM ATP, but not with 5 mM ATP. This activation may be explained by the loss of endogenous ATP from the cell when the intracellular solution contains 0.3 mM ATP. Kir6.1-SUR1 currents were also activated by diazoxide; this activation was greater with 0.3 mM ATP1 than with 5 mM ATP1. 4. We conclude that SUR1 is required to confer both diazoxide and ATP sensitivity on Kir6.1.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1160671Documentos Relacionados
- Sulphonylurea receptor 2B and Kir6.1 form a sulphonylurea-sensitive but ATP-insensitive K+ channel.
- ATP-dependent interaction of the cytosolic domains of the inwardly rectifying K+ channel Kir6.2 revealed by fluorescence resonance energy transfer
- Intracellular ATP activates inwardly rectifying K+ channels in human and monkey retinal Müller (glial) cells.
- Cloning and electrophysiological analysis of KST1, an inward rectifying K+ channel expressed in potato guard cells.
- Effects of external and internal K+ ions on magnesium block of inwardly rectifying K+ channels in guinea-pig heart cells.