title: Green fluorescent protein-tagged apolipoprotein E: A useful marker for the study of hepatic lipoprotein egress.
abstract: Apolipoprotein E (ApoE), a component of very-low-density and high-density lipoproteins, participates in many aspects of lipid transport in the bloodstream. Underscoring its important functions, ApoE isoforms have been associated with metabolic and circulatory disease. ApoE is also incorporated into hepatitis C virus (HCV) particles, and promotes their production and infectivity. Live cell imaging analysis of ApoE behavior during secretion from producing cells thus has the potential to reveal important details regarding lipoprotein and HCV particle biogenesis and secretion from cells. However, this approach requires expression of fluorescently tagged ApoE constructs that need to faithfully reproduce known ApoE behaviors. Herein, we evaluate the usefulness of using an ApoE-GFP fusion protein in studying hepatocyte-derived, ApoE-containing lipoproteins and HCV particles. We show that while ApoE-GFP alone is not sufficient to support infectious HCV production, it nonetheless colocalizes intracellularly and associates with secreted untagged lipoprotein components. Furthermore, its rate of secretion from hepatic cells is indistinguishable from that of untagged ApoE. ApoE-GFP thus represents a useful marker for ApoE-containing hepatic lipoproteins.
authors.affiliation: Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York.|Laboratory of Virology and Infectious Disease, and Center for the Study of Hepatitis C, The Rockefeller University, New York, New York.
authors.forename: Constantin N
authors.initials: CN
authors.lastname: Takacs
authors.affiliation: Laboratory of Virology and Infectious Disease, and Center for the Study of Hepatitis C, The Rockefeller University, New York, New York.
authors.forename: Ursula
authors.initials: U
authors.lastname: Andreo
authors.affiliation: Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York.
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Belote
authors.affiliation: Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York.
authors.forename: Joan
authors.initials: J
authors.lastname: Pulupa
authors.affiliation: Laboratory of Virology and Infectious Disease, and Center for the Study of Hepatitis C, The Rockefeller University, New York, New York.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Scull
authors.affiliation: Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York.
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Gleason
authors.affiliation: Laboratory of Virology and Infectious Disease, and Center for the Study of Hepatitis C, The Rockefeller University, New York, New York.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Rice
authors.affiliation: Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York.
authors.forename: Sanford M
authors.identifier: 0000-0002-8615-4224
authors.initials: SM
authors.lastname: Simon
mesh_terms: D001057:Apolipoproteins E / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism*; D002460:Cell Line; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D016174:Hepacivirus / Q000472:pathogenicity; D022781:Hepatocytes / Q000378:metabolism* / Q000821:virology; D006801:Humans; D008099:Liver / Q000378:metabolism* / Q000821:virology; D019065:Virus Assembly / Q000502:physiology; D057074:Virus Release / Q000502:physiology*
chemical_list: D001057:Apolipoproteins E; D015415:Biomarkers; D049452:Green Fluorescent Proteins
keywords: 
  ApoE
  ; 
  HCV
  ; VLDL; hepatitis; hepatocyte; lipoprotein