Isolation and characterization of the human gene encoding Ito: further diversity by alternative mRNA splicing.
The transient outward K+ current (Ito) in the heart is responsible for the initial phase of repolarization and for setting the plateau voltage of the ventricular action potential. Recently, Kv4.3 has emerged as the leading candidate alpha-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.
Kong
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Department of Medicine, Section of Molecular and Cellular Cardiology, Johns Hopkins University, Baltimore, Maryland 21205, USA.
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Yamagishi
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Ashen
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Stetten
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Tomaselli
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D017398:Alternative Splicing; D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D002478:Cells, Cultured; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D005796:Genes / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D015894:Genome, Human; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger / Q000235:genetics*; D051672:Shal Potassium Channels
D018076:DNA, Complementary; C497021:KCND3 protein, human; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger; D051672:Shal Potassium Channels