title: Small heat shock protein 20 (Hsp20) facilitates nuclear import of protein kinase D 1 (PKD1) during cardiac hypertrophy.
abstract: BACKGROUND
  Nuclear import of protein kinase D1 (PKD1) is an important event in the transcriptional regulation of cardiac gene reprogramming leading to the hypertrophic growth response, however, little is known about the molecular events that govern this event. We have identified a novel complex between PKD1 and a heat shock protein (Hsp), Hsp20, which has been implicated as cardioprotective. This study aims to characterize the role of the complex in PKD1-mediated myocardial regulatory mechanisms that depend on PKD1 nuclear translocation.
  
  
  RESULTS
  In mapping the Hsp20 binding sites on PKD1 within its catalytic unit using peptide array analysis, we were able to develop a cell-permeable peptide that disrupts the Hsp20-PKD1 complex. We use this peptide to show that formation of the Hsp20-PKD1 complex is essential for PKD1 nuclear translocation, signaling mechanisms leading to hypertrophy, activation of the fetal gene programme and pathological cardiac remodeling leading to cardiac fibrosis.
  
  
  CONCLUSIONS
  These results identify a new signaling complex that is pivotal to pathological remodelling of the heart that could be targeted therapeutically.
authors.affiliation: Institute of Cardiovascular and Medical sciences, CMVLS, University of Glasgow, Glasgow, G128QQ, UK. angie.sin@queensu.ca.
authors.forename: Yuan Yan
authors.initials: YY
authors.lastname: Sin
authors.affiliation: Institute of Cardiovascular and Medical sciences, CMVLS, University of Glasgow, Glasgow, G128QQ, UK. tamara.martin@glasgow.ac.uk.
authors.forename: Tamara P
authors.initials: TP
authors.lastname: Martin
authors.affiliation: Institute of Cardiovascular and Medical sciences, CMVLS, University of Glasgow, Glasgow, G128QQ, UK. 0901357W@student.gla.ac.uk.
authors.forename: Lauren
authors.initials: L
authors.lastname: Wills
authors.affiliation: Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Hamnett building, 161 Cathedral Street, Glasgow, G4 ORE, UK. susan.currie@strath.ac.uk.
authors.forename: Susan
authors.initials: S
authors.lastname: Currie
authors.affiliation: Institute of Cardiovascular and Medical sciences, CMVLS, University of Glasgow, Glasgow, G128QQ, UK. george.baillie@glasgow.ac.uk.
authors.forename: George S
authors.initials: GS
authors.lastname: Baillie
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D001665:Binding Sites; D006332:Cardiomegaly / Q000378:metabolism* / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism* / Q000473:pathology; D050886:HSP20 Heat-Shock Proteins / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism*; D009124:Muscle Proteins / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction
chemical_list: D050886:HSP20 Heat-Shock Proteins; D046912:Multiprotein Complexes; D009124:Muscle Proteins; C087458:Hspb6 protein, rat; C089212:protein kinase D; D011493:Protein Kinase C