title: Small heat shock protein Hsp27 is required for proper heart tube formation.
abstract: The small heat shock protein Hsp27 has been shown to be involved in a diverse array of cellular processes, including cellular stress response, protein chaperone activity, regulation of cellular glutathione levels, apoptotic signaling, and regulation of actin polymerization and stability. Furthermore, mutation within Hsp27 has been associated with the human congenital neuropathy Charcot-Marie Tooth (CMT) disease. Hsp27 is known to be expressed in developing embryonic tissues; however, little has been done to determine the endogenous requirement for Hsp27 in developing embryos. In this study, we show that depletion of XHSP27 protein results in a failure of cardiac progenitor fusion resulting in cardia bifida. Furthermore, we demonstrate a concomitant disorganization of actin filament organization and defects in myofibril assembly. Moreover, these defects are not associated with alterations in specification or differentiation. We have thus demonstrated a critical requirement for XHSP27 in developing cardiac and skeletal muscle tissues.
authors.affiliation: Department of Biology, UNC-Chapel Hill, Chapel Hill, North Carolina 27599-3280, USA.
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Brown
authors.forename: Kathleen S
authors.initials: KS
authors.lastname: Christine
authors.forename: Christopher
authors.initials: C
authors.lastname: Showell
authors.forename: Frank L
authors.initials: FL
authors.lastname: Conlon
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050888:Heat-Shock Proteins, Small / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D014176:Protein Biosynthesis; D016415:Sequence Alignment; D019170:Somites / Q000196:embryology / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D014982:Xenopus laevis
chemical_list: D000199:Actins; D006360:Heat-Shock Proteins; D050888:Heat-Shock Proteins, Small