Reconstitution of IKATP: an inward rectifier subunit plus the sulfonylurea receptor.
A member of the inwardly rectifying potassium channel family was cloned here. The channel, called BIR (Kir6.2), was expressed in large amounts in rat pancreatic islets and glucose-responsive insulin-secreting cell lines. Coexpression with the sulfonylurea receptor SUR reconstituted an inwardly rectifying potassium conductance of 76 picosiemens that was sensitive to adenosine triphosphate (ATP) (IKATP) and was inhibited by sulfonylureas and activated by diazoxide. The data indicate that these pancreatic beta cell potassium channels are a complex composed of at least two subunits--BIR, a member of the inward rectifier potassium channel family, and SUR, a member of the ATP-binding cassette superfamily. Gene mapping data show that these two potassium channel subunit genes are clustered on human chromosome 11 at position 11p15.1.
Inagaki
N
N
Division of Molecular Medicine, Chiba University School of Medicine, Japan.
Gonoi
T
T
Clement
J P
JP
Namba
N
N
Inazawa
J
J
Gonzalez
G
G
Aguilar-Bryan
L
L
Seino
S
S
Bryan
J
J
D018528:ATP-Binding Cassette Transporters; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11; D003001:Cloning, Molecular; D006224:Cricetinae; D003981:Diazoxide / Q000494:pharmacology; D006801:Humans; D007515:Islets of Langerhans / Q000378:metabolism; D054086:KATP Channels; D051379:Mice; D008969:Molecular Sequence Data; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying; D051381:Rats; D011955:Receptors, Drug / Q000737:chemistry* / Q000378:metabolism; D012413:Rubidium / Q000378:metabolism; D013453:Sulfonylurea Compounds / Q000494:pharmacology; D064233:Sulfonylurea Receptors
D018528:ATP-Binding Cassette Transporters; D054086:KATP Channels; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D011955:Receptors, Drug; D013453:Sulfonylurea Compounds; D064233:Sulfonylurea Receptors; C092520:uK-ATP-1 potassium channel; D000255:Adenosine Triphosphate; D012413:Rubidium; D003981:Diazoxide; D011188:Potassium