Regulation of Kv11.1 isoform expression by polyadenylate binding protein nuclear 1

Matthew R. Stump, Rachel T. Nguyen, Rachel H. Drgastin, Delaney Search, Qiuming Gong, Zhengfeng Zhou

    Research output: Contribution to journalArticlepeer-review

    Abstract

    The Kv11.1 voltage-gated potassium channel, encoded by the KCNH2 gene, conducts the rapidly activating delayed rectifier current in the heart. KCNH2 pre-mRNA undergoes alternative polyadenylation to generate two C-terminal Kv11.1 isoforms in the heart. Utilization of a poly(A) signal in exon 15 produces the full-length, functional Kv11.1a isoform, while intron 9 polyadenylation generates the C-terminally truncated, nonfunctional Kv11.1a-USO isoform. The relative expression of Kv11.1a and Kv11.1a-USO isoforms plays an important role in the regulation of Kv11.1 channel function. In this study, we tested the hypothesis that the RNA polyadenylate binding protein nuclear 1 (PABPN1) interacts with a unique 22 nt adenosine stretch adjacent to the intron 9 poly(A) signal and regulates KCNH2 pre-mRNA alternative polyadenylation and the relative expression of Kv11.1a C-terminal isoforms. We showed that PABPN1 inhibited intron 9 poly(A) activity using luciferase reporter assays, tandem poly(A) reporter assays, and RNA pulldown assays. We also showed that PABPN1 increased the relative expression level of the functional Kv11.1a isoform using RNase protection assays, immunoblot analyses, and patch clamp recordings. Our present findings suggest a novel role for the RNA-binding protein PABPN1 in the regulation of functional and nonfunctional Kv11.1 isoform expression.

    Original languageEnglish (US)
    Article number863
    Pages (from-to)1-12
    Number of pages12
    JournalInternational journal of molecular sciences
    Volume22
    Issue number2
    DOIs
    StatePublished - Jan 2 2021

    Keywords

    • Alternative polyadenylation
    • HERG
    • Long QT syndrome
    • Splicing

    ASJC Scopus subject areas

    • Catalysis
    • Molecular Biology
    • Spectroscopy
    • Computer Science Applications
    • Physical and Theoretical Chemistry
    • Organic Chemistry
    • Inorganic Chemistry

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