Title: Characterization of a mammalian cDNA for an inactivating voltage-sensitive K+ channel.

Authors: T J Baldwin, M L Tsaur, G A Lopez, Y N Jan, L Y Jan

Journal, date & volume: Neuron, 1991 Sep , 7, 471-83

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/1840649

Abstract
A cDNA clone encoding a K+ channel polypeptide with 72% amino acid sequence identity to Drosophila Shal was isolated from rat hippocampus. Functional expression of the cDNA in Xenopus oocytes generated 4-amino-pyridine-sensitive K+ channels displaying rapid inactivation kinetics. The fastest component of inactivation was slowed by the deletion of 3 basic residues in the amino-terminal region. Northern blots revealed that the mRNA encoding this K+ channel polypeptide was expressed at a similar level in the brain and in the heart. In situ hybridization revealed that the mRNA encoding this K+ channel appeared concentrated in the hippocampus, dentate gyrus, and habenular nucleus in the brain. Thus, this K+ channel polypeptide is likely to form some of the A-type K+ channels expressed in the mammalian nervous system and heart.