PubMed 8987734
Automatically associated channels: Kv1.4 , Kv3.1 , Kv4.1 , Kv4.2
Title: A novel subunit for shal K+ channels radically alters activation and inactivation.
Authors: T Jegla, L Salkoff
Journal, date & volume: J. Neurosci., 1997 Jan 1 , 17, 32-44
PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8987734
Abstract
Shal (Kv4) potassium channel genes encode classical subthreshold A-currents, and their regulation may be a key factor in determining neuronal firing frequency. The inactivation rate of Shal channels is increased by a presently unidentified class of proteins in both Drosophila and mammals. We have cloned a novel Shal channel subunit (jShalgamma1) from the jellyfish Polyorchis penicillatus that alters Shal currents from both invertebrates and vertebrates. When co-expressed with the conserved jellyfish Shal homolog jShal1, jShalgamma1 dramatically changes both the rate of inactivation and voltage range of activation and steady-state inactivation. jShalgamma1 provides fast inactivation by a classic N-type mechanism, which is independent of its effects on voltage dependence. jShalgamma1 forms functional channels only as a heteromultimer, and jShalgamma1 + jShal1 heteromultimers are functional only in a 2:2 subunit stoichiometry.