title: A Proteomics Approach to Identify New Putative Cardiac Intercalated Disk Proteins.
abstract: Synchronous beating of the heart is dependent on the efficient functioning of the cardiac intercalated disk (ID). The ID is composed of a complex protein network enabling electrical continuity and chemical communication between individual cardiomyocytes. Recently, several different studies have shed light on increasingly prevalent cardiac diseases involving the ID. Insufficient knowledge of its composition makes it difficult to study these disease mechanisms in more detail and therefore here we aim expand the ID proteome. Here, using a combination of general membrane enrichment, in-depth quantitative proteomics and an intracellular location driven bioinformatics approach, we aim to discover new putative ID proteins in rat ventricular tissue.
  
  
  
  General membrane isolation, enriched amongst others also with ID proteins as based on presence of the established markers connexin-43 and n-cadherin, was performed using centrifugation. By mass spectrometry, we quantitatively evaluated the level of 3455 proteins in the enriched membrane fraction (EMF) and its counterpart, the soluble cytoplasmic fraction. These data were stringently filtered to generate a final set of 97 enriched, putative ID proteins. These included Cx43 and n-cadherin, but also many interesting novel candidates. We selected 4 candidates (Flotillin-2 (FLOT2), Nexilin (NEXN), Popeye-domain-containg-protein 2 (POPDC2) and thioredoxin-related-transmembrane-protein 2 (TMX2)) and confirmed their co-localization with n-cadherin in the ID of human and rat heart cryo-sections, and isolated dog cardiomyocytes.
  
  
  
  The presented proteomics dataset of putative new ID proteins is a valuable resource for future research into this important molecular intersection of the heart.
authors.affiliation: Dept of Medical Physiology, Division of Heart & Lungs, University Medical Centre Utrecht, Utrecht, The Netherlands.|Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.
authors.forename: Siddarth
authors.initials: S
authors.lastname: Soni
authors.affiliation: Dept of Medical Physiology, Division of Heart & Lungs, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Antonia J A
authors.initials: AJ
authors.lastname: Raaijmakers
authors.affiliation: Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.|Netherlands Proteomics Centre, Utrecht, The Netherlands.
authors.forename: Linsey M
authors.initials: LM
authors.lastname: Raaijmakers
authors.affiliation: Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.|Netherlands Proteomics Centre, Utrecht, The Netherlands.
authors.forename: J Mirjam A
authors.initials: JM
authors.lastname: Damen
authors.affiliation: Dept of Medical Physiology, Division of Heart & Lungs, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Leonie
authors.initials: L
authors.lastname: van Stuijvenberg
authors.affiliation: Dept of Medical Physiology, Division of Heart & Lungs, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Vos
authors.affiliation: Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.|Netherlands Proteomics Centre, Utrecht, The Netherlands.
authors.forename: Albert J R
authors.initials: AJ
authors.lastname: Heck
authors.affiliation: Dept of Medical Physiology, Division of Heart & Lungs, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Toon A B
authors.initials: TA
authors.lastname: van Veen
authors.affiliation: Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.|Netherlands Proteomics Centre, Utrecht, The Netherlands.
authors.forename: Arjen
authors.initials: A
authors.lastname: Scholten
mesh_terms: D000818:Animals; D017629:Gap Junctions / Q000378:metabolism; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D040901:Proteomics; D051381:Rats; D017208:Rats, Wistar
chemical_list: D008565:Membrane Proteins; C106354:flotillins