Isolation and characterization of the human gene encoding the
transient outward potassium current: further diversity by alternative
mrna splicing.
Kong, Wei, Sunny Po, Toshio Yamagishi, M. Dominique Ashen, Gail
Stetten#, Gordon F. Tomaselli.
Department of Medicine, Section of Molecular and Cellular
Cardiology and #Department of Gynecology and Obstetrics, Johns
Hopkins University
APStracts 5:0341H, 1998.
The transient outward potassium current (Ito) in the heart is
responsible for the initial phase of repolarization and setting the
plateau voltage of the ventricular action potential. Recently, Kv4.3
has emerged as the leading candidate a subunit gene that underlies
Ito in larger mammals such as dogs and humans. We have cloned the
human Kv4.3 homolog and describe a carboxyl terminal splice variant
that inserts 19 amino acids with a consensus protein kinase C (PKC)
phosphorylation site into the protein after the last membrane
-spanning segment. The coding region of Kv4.3 is comprised of at least
five exons and is located on chromosome 1p13.3. In the basal state
the basic biophysical properties of both of the splice variants are
identical.
Received 4 June 1998; accepted in final form 19 August 1998.
APS Manuscript Number H449-8.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 21 September 1998