title: Peroxidasin-like protein: a novel peroxidase homologue in the human heart.
abstract: OBJECTIVE
  Peroxidases serve diverse biological functions including well-characterized activities in host defence and hormone biosynthesis. More recently, peroxidasin (PXDN) was found to be involved in collagen IV cross-linking in the extracellular matrix (ECM). The aim of this study was to characterize the expression and function of peroxidasin-like protein (PXDNL), a previously unknown peroxidase homologue.
  
  
  RESULTS
  We cloned the PXDNL cDNA from the human heart and identified its expression pattern by northern blot, in situ hybridization, and immunohistochemistry. PXDNL is expressed exclusively in the heart and it has evolved to lose its peroxidase activity. The protein is produced by cardiomyocytes and localizes to cell-cell junctions. We also demonstrate that PXDNL can form a complex with PXDN and antagonizes its peroxidase activity. Furthermore, we show an increased expression of PXDNL in the failing myocardium.
  
  
  CONCLUSIONS
  PXDNL is a unique component of the heart with a recently evolved inactivation of peroxidase function. The elevation of PXDNL levels in the failing heart may contribute to ECM dysregulation due to its antagonism of PXDN function.
authors.affiliation: Department of Physiology, Faculty of Medicine, Semmelweis University, PO Box 259, Budapest H-1444, Hungary.
authors.forename: Zalán
authors.initials: Z
authors.lastname: Péterfi
authors.forename: Zsuzsanna E
authors.initials: ZE
authors.lastname: Tóth
authors.forename: Hajnal A
authors.initials: HA
authors.lastname: Kovács
authors.forename: Eniko
authors.initials: E
authors.lastname: Lázár
authors.forename: Adrienn
authors.initials: A
authors.lastname: Sum
authors.forename: Agnes
authors.initials: A
authors.lastname: Donkó
authors.forename: Gábor
authors.initials: G
authors.lastname: Sirokmány
authors.forename: Ajay M
authors.initials: AM
authors.lastname: Shah
authors.forename: Miklós
authors.initials: M
authors.lastname: Geiszt
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000494:pharmacology*; D005786:Gene Expression Regulation; D006321:Heart / Q000187:drug effects*; D006333:Heart Failure / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D010084:Oxidation-Reduction / Q000187:drug effects; D009195:Peroxidase / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D000097423:Peroxidasin
chemical_list: D016326:Extracellular Matrix Proteins; D009195:Peroxidase; D012333:RNA, Messenger; D000097423:Peroxidasin
keywords: Extracellular matrix; Peroxidase; Peroxidasin; Peroxidasin-like protein; Reactive oxygen species