Identification of G protein-regulated inwardly rectifying K+ channels in rat brain oligodendrocytes.
Rat brain oligodendroglia in culture express a dominant inwardly rectifying K+ current IKIR which can be inhibited through G. proteins by the activation of glial G protein-coupled receptors. Electrophysiologically we have isolated in these cells several conductances of K+ inward rectifiers (KIR) between 12 and 175 pS. Experiments on the single channel level with preloading or bath-application of GTP gamma S revealed the selective suppression of an 18 pS and maybe other KIR conductances, possibly via a direct membrane-delimited mechanism. mRNA amplification from single oligodendrocytes together with polymerase chain reaction resulted in the isolation of IRK-type K+ channels which may correspond to the channel species negatively controlled by G proteins.
Karschin
A
A
Max-Planck-Institute for Biophysical Chemistry, Molecular Neurobiology of Signal Transduction, Göttingen, Germany.
Wischmeyer
E
E
D000818:Animals; D001921:Brain / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006801:Humans; D007231:Infant, Newborn; D009836:Oligodendroglia / Q000502:physiology*; D015221:Potassium Channels / Q000502:physiology*; D012333:RNA, Messenger; D051381:Rats
D015221:Potassium Channels; D012333:RNA, Messenger; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins