Premium
Molecular cloning and characterization of two voltage‐gated K + channel cDNAs from human ventricle
Author(s) -
Tamkun Michael M.,
Knoth Karen M.,
Walbridge Julia A.,
Kroemer Heyo,
Roden Dan M.,
Glover Deborah M.
Publication year - 1991
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.5.3.2001794
Subject(s) - complementary dna , ventricle , biology , microbiology and biotechnology , voltage gated ion channel , cloning (programming) , peptide sequence , gene , amino acid , coding region , ion channel , biochemistry , medicine , receptor , computer science , programming language
K + channels represent the most complex class of voltage‐gated ion channels from both functional and structural standpoints. In the heart these channels are responsible for the rapid repolarizing phases of the action potential and are the targets of several antiarrhythmic drugs. Full‐length cDNA clones were isolated from human ventricular libraries that encode two voltage‐gated K + channels. These two cDNAs, designated HK1 and HK2, encode proteins of 653 and 605 amino acids, respectively. HK1 is the human equivalent (98% identity) of an inactivating K + channel previously described in rat heart (RHK1) whereas the HK2 channel is 86% identical to a cloned rat brain K + channel (Kv1). The only amino acid sequence identity (72%) between HK1 and HK2 is within the central region containing the membrane spanning domains. Northern blot analysis of human mRNA indicated that HK1 is slightly more abundant in ventricle than atrium whereas HK2 is much more abundant in atrium relative to ventricle. Both channel transcripts are present in ventricle at levels equivalent to voltage‐gated Na + channels. Analysis of the gene encoding HK1 suggests the coding sequence is intronless and is represented once in the human genome.—Tamkun, M. M.; Knoth, K. M.; Walbridge, J. A.; Kroemer, H.; Roden, D. M.; Glover, D. M. Molecular cloning and characterization of two voltage‐gated K + channel cDNAs from human ventricle. FASEB J. 5: 331–337; 1991.