Kir2.1 Interactome Mapping Uncovers PKP4 as a Modulator of the Kir2.1-Regulated Inward Rectifier Potassium Currents

• Published in: Molecular & cellular proteomics Vol. 19; no. 9; pp. 1436 - 1449
• Main Authors: Park, Sung-Soo, Ponce-Balbuena, Daniela, Kuick, Rork, Guerrero-Serna, Guadalupe, Yoon, Justin, Mellacheruvu, Dattatreya, Conlon, Kevin P., Basrur, Venkatesha, Nesvizhskii, Alexey I., Jalife, José, Rual, Jean-François
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2020; American Society for Biochemistry and Molecular Biology
• Subjects: Action Potentials - drug effects; Action Potentials - physiology; Andersen Syndrome - genetics; Andersen Syndrome - metabolism; Andersen Syndrome - physiopathology; BioID; cardiomyopathy; cardiovascular disease; cardiovascular function or biology; Chromatography, Liquid; Desmosomes - drug effects; Desmosomes - metabolism; HEK293 Cells; Humans; inward rectifier potassium current; Kir2.1; Lysosomes - metabolism; macromolecular complex analysis; mass spectrometry; Molecular Chaperones - metabolism; Mutation; Myocytes, Cardiac - drug effects; Myocytes, Cardiac - metabolism; Patch-Clamp Techniques; PKP4; Plakophilins - metabolism; Potassium - metabolism; Potassium Channels, Inwardly Rectifying - genetics; Potassium Channels, Inwardly Rectifying - metabolism; Protein Interaction Maps - genetics; Protein Interaction Maps - physiology; Protein Transport - genetics; Protein Transport - physiology; Protein-protein interactions; Signal Transduction - genetics; Signal Transduction - physiology; Somatomedins - metabolism; Tandem Mass Spectrometry; Utrophin - metabolism; BioID; inward rectifier potassium current; cardiovascular disease; macromolecular complex analysis; Kir2.1; cardiovascular function or biology; mass spectrometry; PKP4; cardiomyopathy; Protein-protein interactions
• ISSN: 1535-9476; 1535-9484; 1535-9484
• DOI: 10.1074/mcp.RA120.002071

A comprehensive map of the Kir2.1 interactome was generated using the proximity-labeling approach BioID. The map encompasses 218 interactions, the vast majority of which are novel, and explores the variations in the interactome profiles of Kir2.1WT versus Kir2.1Δ314-315, a trafficking deficient ATS1 mutant, thus uncovering molecular mechanisms whose malfunctions may underlie ATS1 disease. PKP4, one of the BioID interactors, is validated as a modulator of Kir2.1-controlled inward rectifier potassium currents. [Display omitted] Highlights •Generation using BioID of a map of the Kir2.1 interactome with 218 interactions.•Identification of Kir2.1WT- versus Kir2.1Δ314-315-preferred interactors.•Identification of the desmosome protein PKP4 as a new modulator of IKir2.1 currents. Kir2.1, a strong inward rectifier potassium channel encoded by the KCNJ2 gene, is a key regulator of the resting membrane potential of the cardiomyocyte and plays an important role in controlling ventricular excitation and action potential duration in the human heart. Mutations in KCNJ2 result in inheritable cardiac diseases in humans, e.g. the type-1 Andersen-Tawil syndrome (ATS1). Understanding the molecular mechanisms that govern the regulation of inward rectifier potassium currents by Kir2.1 in both normal and disease contexts should help uncover novel targets for therapeutic intervention in ATS1 and other Kir2.1-associated channelopathies. The information available to date on protein-protein interactions involving Kir2.1 channels remains limited. Additional efforts are necessary to provide a comprehensive map of the Kir2.1 interactome. Here we describe the generation of a comprehensive map of the Kir2.1 interactome using the proximity-labeling approach BioID. Most of the 218 high-confidence Kir2.1 channel interactions we identified are novel and encompass various molecular mechanisms of Kir2.1 function, ranging from intracellular trafficking to cross-talk with the insulin-like growth factor receptor signaling pathway, as well as lysosomal degradation. Our map also explores the variations in the interactome profiles of Kir2.1WTversus Kir2.1Δ314-315, a trafficking deficient ATS1 mutant, thus uncovering molecular mechanisms whose malfunctions may underlie ATS1 disease. Finally, using patch-clamp analysis, we validate the functional relevance of PKP4, one of our top BioID interactors, to the modulation of Kir2.1-controlled inward rectifier potassium currents. Our results validate the power of our BioID approach in identifying functionally relevant Kir2.1 interactors and underline the value of our Kir2.1 interactome as a repository for numerous novel biological hypotheses on Kir2.1 and Kir2.1-associated diseases.