CLONING, FUNCTIONAL EXPRESSION AND MESSENGER-RNA DISTRIBUTION OF AN INWARDLY RECTIFYING POTASSIUM CHANNEL PROTEIN

In GH(3)/B-6 cells at least two different inward K+ currents are obser ved that are regulated by thyrotropin-releasing hormone and somatostat in, respectively, Using a polymerase chain reaction based approach a c DNA was isolated and functionally expressed in human embryonic kidney cells that encodes an inward rectifier K+ channel, rIRK3, with a predi cted molecular mass of 49.7 kDa, Corresponding transcripts of 2.6 kb h ave been detected in rat brain, pituitary and GH(3)/B-6 cells, In situ hybridization revealed that rIRK3 mRNA is distributed throughout the brain and occurs predominantly in the piriform cortex, indusium griseu m, supraoptic nucleus, facial nucleus and cerebellar Purkinje cells.