Biomaterial Database

The antiviral protein, viperin, localizes to lipid droplets via its N-terminal amphipathic alpha-helix. 2009

Ella R Hinson, and Peter Cresswell

Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520-8011, USA.

Lipid droplets are intracellular lipid-storage organelles that are thought to be derived from the endoplasmic reticulum (ER). Several pathogens, notably hepatitis C virus, use lipid droplets for replication. Numerous questions remain about how lipid droplets are generated and used by viruses. Here we show that the IFN-induced antiviral protein viperin, which localizes to the cytosolic face of the ER and inhibits HCV, localizes to lipid droplets. We show that the N-terminal amphipathic alpha-helix of viperin that is responsible for ER localization is also necessary and sufficient to localize both viperin and the fluorescent protein dsRed to lipid droplets. Point mutations in the alpha-helix that prevent ER association also disrupt lipid droplet association, and sequential deletion mutants indicate that the same number of helical turns are necessary for ER and lipid droplet association. Finally, we show that the N-terminal amphipathic alpha-helix of the hepatitis C viral protein NS5A can localize dsRed and viperin to lipid droplets. These findings indicate that the amphipathic alpha-helices of viperin and NS5A are lipid droplet-targeting domains and suggest that viperin inhibits HCV by localizing to lipid droplets using a domain and mechanism similar to that used by HCV itself.

UI	MeSH Term	Description	Entries
D008264	Macrophages	The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)	Bone Marrow-Derived Macrophages,Monocyte-Derived Macrophages,Macrophage,Macrophages, Monocyte-Derived,Bone Marrow Derived Macrophages,Bone Marrow-Derived Macrophage,Macrophage, Bone Marrow-Derived,Macrophage, Monocyte-Derived,Macrophages, Bone Marrow-Derived,Macrophages, Monocyte Derived,Monocyte Derived Macrophages,Monocyte-Derived Macrophage
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D004721	Endoplasmic Reticulum	A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)	Ergastoplasm,Reticulum, Endoplasmic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015153	Blotting, Western	Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.	Immunoblotting, Western,Western Blotting,Western Immunoblotting,Blot, Western,Immunoblot, Western,Western Blot,Western Immunoblot,Blots, Western,Blottings, Western,Immunoblots, Western,Immunoblottings, Western,Western Blots,Western Blottings,Western Immunoblots,Western Immunoblottings
D016174	Hepacivirus	A genus of FLAVIVIRIDAE causing parenterally-transmitted HEPATITIS C which is associated with transfusions and drug abuse. Hepatitis C virus is the type species.	Hepatitis C virus,Hepatitis C-Like Viruses,Hepaciviruses,Hepatitis C Like Viruses,Hepatitis C viruses,Hepatitis C-Like Virus
D017354	Point Mutation	A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.	Mutation, Point,Mutations, Point,Point Mutations
D017361	Viral Nonstructural Proteins	Proteins encoded by a VIRAL GENOME that are not structural components of VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.	Nonstructural Proteins, Viral,NS Proteins, Viral,Viral NS Proteins,Viral Non-Structural Proteins,Viral Nonstructural Protein,Viral Nonstructural Proteins NS1,Viral Nonstructural Proteins NS2,Nonstructural Protein, Viral,Viral Non Structural Proteins