title: Membrane topography of cardiac triadin.
abstract: Fusion constructs of partial sequences of triadin that contain green fluorescent protein at the N-terminus and glutathione transferase at the C-terminus have been expressed in human embryonic kidney -293 cells. A comparison of the subcellular disposition of a range of triadin fusion peptides indicates localization either to a few large organelles as a default target or to endoplasmic reticulum when amino acids 68-98 are present and structurally intact. Fluorescence from the conjugate of monochlorobimane with glutathione identifies whether the C-terminus has a cytoplasmic or luminal location. A stable transit of the membrane occurs in triadin2-98. Triadin2-117 and 2-267 give both cytoplasmic and luminal C-termini. Both triadin89-117 and triadin89-267 distribute in membranes, but do not cross them. The data are interpreted to indicate that cardiac triadin contains an alpha-helical membrane transit through the hydrophobic domain, 49-68, and a membrane association through the short hydrophobic domain, 102-114.
authors.affiliation: Department of Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, Florida 33136, USA. acaswell@chroma.med.miami.edu
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Caswell
authors.forename: Neil R
authors.initials: NR
authors.lastname: Brandt
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics; D002478:Cells, Cultured; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D009124:Muscle Proteins / Q000737:chemistry* / Q000235:genetics; D009206:Myocardium / Q000737:chemistry*; D015388:Organelles / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry
chemical_list: D002352:Carrier Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; C498269:TRDN protein, human; C070048:triadin; D049452:Green Fluorescent Proteins