Back to Search
Start Over
Cloning and functional expression of the cDNA encoding an inwardly-rectifying potassium channel expressed in pancreatic beta-cells and in the brain
- Source :
- FEBS letters. 367(1)
- Publication Year :
- 1995
-
Abstract
- A cDNA clone encoding an inwardly-rectifying K-channel (BIR1) was isolated from insulinoma cells. The predicted amino acid sequence shares 72% identity with the cardiac ATP-sensitive K-channel rcKATP (KATP-1; [6]). The mRNA is expressed in the brain and insulinoma cells. Heterologous expression in Xenopus oocytes produced currents which were K+-selective, time-independent and showed inward rectification. The currents were blocked by external barium and caesium, but insensitive to tolbutamide and diazoxide. In inside-out patches, channel activity was not blocked by 1 mM internal ATP. The sequence homology with KATP-1 suggests that BIR1 is a subunit of a brain and β-cell KATP channel. However, pharmacological differences and the lack of ATP-sensitivity, suggest that if, this is the case, heterologous subunits must exert strong modulatory influences on the native channel.
- Subjects :
- endocrine system
DNA, Complementary
Patch-Clamp Techniques
Potassium Channels
Protein subunit
Xenopus
Molecular Sequence Data
Biophysics
Heterologous
Biology
Biochemistry
Islets of Langerhans
ATP-sensitive K-channel
Structural Biology
Complementary DNA
Genetics
Diazoxide
medicine
Tumor Cells, Cultured
Animals
Humans
Amino Acid Sequence
Cloning, Molecular
Pancreatic β-cell
Molecular Biology
Peptide sequence
BIR1
Base Sequence
Inward-rectifier potassium ion channel
Brain
Cell Biology
Molecular biology
Potassium channel
Rats
K-channel
Inward rectifyer
Insulinoma
Heterologous expression
Sequence Alignment
medicine.drug
Subjects
Details
- Language :
- English
- ISSN :
- 18733468 and 00145793
- Volume :
- 367
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- FEBS letters
- Accession number :
- edsair.doi.dedup.....66eb073eb1e6c0258b5616a61510b91b