Expression of mRNA for voltage-dependent and inward-rectifying K channels in GH3/B6 cells and rat pituitary.
The expression of mRNA for voltage-dependent (Kv) and inward-rectifying K channels (Kir) was studied in clonal rat somato-mammotroph cells (GH3/B6 cells) and rat pituitary using reverse transcription-polymerase chain reaction (RT-PCR). In GH3/B6 cells transcripts for 16 different Kv channel alpha-subunits (seven Shaker-related: Kv1.2, Kv1.4, Kv1.5, Kv2.1, Kv3.2, Kv4.1, Kv5.1; six EAG: eag1, erg1, erg2, elk1-elk3; three KCNQ: KCNQ1-KCNQ3) and for five different Kir channel alpha-subunits (Kir1.1, Kir2.3, Kir3.2, Kir3.3, Kir6.2) were found. In addition, transcripts for a short isoform of Kvbeta2 and transcripts for Kvbeta3 subunits were present. In rat pituitary transcripts for 21 different Kv channel alpha-subunits (11 Shaker-related: Kv1.3, Kv1.4, Kv1.6, Kv2.1, Kv2.2, Kv3.2, Kv3.4, Kv4.1, Kv4.2, Kv4.3, Kv6.1; seven EAG: eag1, erg1-erg3, elk1-elk3; three KCNQ: KCNQ1-KCNQ3) and nine Kir channel alpha-subunits (Kir1.1, Kir2.2, Kir3.1-Kir3.4, Kir4.1, Kir6.1, Kir6. 2) were found. In addition, all tested auxiliary subunits (Kvbeta1-Kvbeta3, minK, SUR1, SUR2) are expressed in the pituitary. The results indicate that the macroscopic K currents in GH3/B6 and pituitary cells are presumably mediated by K channels constructed by a larger number of K channel alpha-subunits and auxiliary beta-subunits than previously distinguished electrophysiologically and pharmacologically.
Wulfsen
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I
Abteilung für Angewandte Physiologie, Institut für Physiologie, Universitätsklinikum Hamburg-Eppendorf, Universität Hamburg, Hamburg, Germany.
Hauber
H P
HP
Schiemann
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D
Bauer
C K
CK
Schwarz
J R
JR
D000818:Animals; D002460:Cell Line; D004553:Electric Conductivity; D051638:Ether-A-Go-Go Potassium Channels; D005260:Female; D015870:Gene Expression; D013006:Growth Hormone / Q000032:analysis; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; D010902:Pituitary Gland / Q000737:chemistry*; D015221:Potassium Channels / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated; D011388:Prolactin / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051637:Shaker Superfamily of Potassium Channels
D051638:Ether-A-Go-Go Potassium Channels; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; C496886:Kcnh1 protein, rat; C496911:Kcnq1 protein, rat; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger; D051637:Shaker Superfamily of Potassium Channels; D011388:Prolactin; D013006:Growth Hormone