@article{65311ecb380e4d52bc37a96c261f9df4,
title = "Localization and functional consequences of a direct interaction between TRIOBP-1 and hERG proteins in the heart",
abstract = "Reduced levels of the cardiac human (h)ERG ion channel protein and the corresponding repolarizing current IKr can cause arrhythmia and sudden cardiac death, but the underlying cellular mechanisms controlling hERG surface expression are not well understood. Here, we identified TRIOBP-1, an F-actin-binding protein previously associated with actin polymerization, as a putative hERGinteracting protein in a yeast-two hybrid screen of a cardiac library. We corroborated this interaction by performing F{\"o}rster resonance energy transfer (FRET) in HEK293 cells and co-immunoprecipitation in HEK293 cells and native cardiac tissue. TRIOBP-1 overexpression reduced hERG surface expression and current density, whereas reducing TRIOBP-1 expression via shRNA knockdown resulted in increased hERG protein levels. Immunolabeling in rat cardiomyocytes showed that native TRIOBP-1 colocalized predominantly with myosin-binding protein C and secondarily with rat ERG. In human stem cell-derived cardiomyocytes, TRIOBP-1 overexpression caused intracellular co-sequestration of hERG signal, reduced native IKr and disrupted action potential repolarization. Ca2+ currents were also somewhat reduced and cell capacitance was increased. These findings establish that TRIOBP-1 interacts directly with hERG and can affect protein levels, IKr magnitude and cardiac membrane excitability.",
keywords = "Action potential, FRET, I, IPSC-CM, KCNH2, TARA, Yeast two-hybrid",
author = "Jones, {David K.} and Johnson, {Ashley C.} and Roti, {Elon C.Roti} and Fang Liu and Rebecca Uelmen and Ayers, {Rebecca A.} and Istvan Baczko and Tester, {David J.} and Ackerman, {Michael J.} and Trudeau, {Matthew C.} and Robertson, {Gail A.}",
note = "Funding Information: The authors acknowledge Dr Michel Streuli (Director of Biologics, Merck and Co., Cambridge, MA, USA) for supplying monoclonal TRIOBP-1 antibodies, Drs Richard L. Moss and J. R. Patel (University of Wisconsin School of Medicine and Public Health (UW SMPH), Madison, WI, USA) for providing human tissue and the myosin binding protein C antibody, Dr Cynthia Carnes (Ohio State University, Columbus, OH, USA) for providing canine cardiac tissue, Dr Lee Eckhardt (Department of Medicine, UW SMPH, Madison, WI, USA) for providing the Kir2.1 adenovirus, and Drs Erick Rios Perez, Catherine Eichel and Eugenia Jones (Dept. of Neuroscience, UW SMPH, Madison, WI, USA) for critical discussions.This work was supported by the National Institutes of Health (NIH) (1R01HL081780 and 1R01HL131403 to G.A.R.); a postdoctoral training award from the University of Wisconsin-Madison Stem Cell and Regenerative Medicine Center and the NIH (K99 HL133482 to D.K.J.); predoctoral fellowships from the American Heart Association, Midwest Affiliate (to E.C.R.R. and RU); an NIH-NRSA postdoctoral fellowship F32HL131189 (to A.C.J.); the Mayo Clinic Windland Smith Rice Comprehensive Sudden Cardiac Death Program (to D.J.T. and M.J.A.); and the Maryland Stem Cell Research Fund (to M.C.T.). Deposited in PMC for release after 12 months Publisher Copyright: {\textcopyright} 2018. Published by The Company of Biologists Ltd.",
year = "2018",
month = mar,
day = "1",
doi = "10.1242/jcs.206730",
language = "English (US)",
volume = "131",
journal = "Journal of cell science",
issn = "0021-9533",
publisher = "Company of Biologists Ltd",
number = "6",
}