Title: mShal, a subfamily of A-type K+ channel cloned from mammalian brain.

Authors: M D Pak, K Baker, M Covarrubias, A Butler, A Ratcliffe, L Salkoff

Journal, date & volume: Proc. Natl. Acad. Sci. U.S.A., 1991 May 15 , 88, 4386-90

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/2034678

Abstract
We have cloned and expressed a mouse brain cDNA, mShal, that encodes a transient, A-type K+ current. mShal, the vertebrate homolog of the Drosophila Shal gene, defines a distinct subfamily of voltage-gated K+ channels. The Shal deduced proteins are more highly conserved between mouse and Drosophila than other presently known K+ channels. mShal carries a "low-threshold" A-type current with a hyperpolarized steady-state inactivation midpoint. Marked similarity was observed between mShal and its Drosophila homolog, fShal, with regard to voltage sensitivity of activation, macroscopic inactivation, steady-state inactivation, and 4-aminopyridine sensitivity. Sequence conservation for Shal proteins is unusually high at the amino terminus, an area considered important for inactivation. Removal of conserved amino-terminal residues from mShal modifies macroscopic inactivation but the transient nature of the current is preserved. Underlying the very high conservation of mShal and fShal may be a role in the nervous system that is conserved in widely divergent species.