Molecular cloning and functional expression of a novel potassium channel β-subunit from human atrium

• Published in: FEBS letters 1995-03, Vol.361 (1), p.13-16
• Main Authors: Majumder, Kumud, De Biasi, Mariella, Wang, Zhiguo, Wible, Barbara A.
• Format: Article
• Language: English
• Subjects: 2(N-morpholino)ethanesulphonic acid; Amino Acid Sequence; amino-terminal; Animals; Atrial Function; base pairs; Base Sequence; cDNA cloning; Cloning, Molecular; HEPES; Human heart; Humans; Ion Channel Gating - genetics; kilobase pairs; Membrane Potentials; MES; Molecular Sequence Data; N-2-hydroxyethyl-piperazine-N′-2-ethanesulfoni c acid; N-terminal; NMDG; Oocytes; PCR; polymerase chain reaction; Potassium channel; Potassium Channels - biosynthesis; Potassium Channels - genetics; Potassium Channels - physiology; Rats; reverse transcriptase polymerase chain reaction; RNA, Messenger - genetics; RT-PCR; saline-sodium citrate; SDS; Sequence Analysis, DNA; Sequence Homology, Amino Acid; sodium dodecyl sulfate; SSC; Xenopus; Xenopus oocyte; β-Subunit
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(95)00120-X

We report the cloning and functional expression of a novel K + channel β-subunit from human atrium, hKvβ3. hKvβ3 is highly homologous to the two β-subunits cloned from rat brain, Kvβ1 and Kvβ2, but has an essentially unique stretch of 79 N-terminal residues. Upon expression in Xenopus oocytes, hKvβ3 accelerates the inactivation of co-injected hKv1.4 currents and induces fast inactivation of non-inactivating co-injected hKv1.5 currents. By contrast, hKvβ3 had no effect on hKv1.1, hKv1.2, or hKv2.1 currents. Thus, hKvβ3 represents a third type of K + channel β-subunit which modulates the kinetics of a unique subset of channels in the Kv1 subfamily.