title: The hepatitis B x antigen anti-apoptotic effector URG7 is localized to the endoplasmic reticulum membrane.
abstract: Hepatitis B x antigen up-regulates the liver expression of URG7 that contributes to sustain chronic virus infection and to increase the risk for hepatocellular carcinoma by its anti-apoptotic activity. We have investigated the subcellular localization of URG7 expressed in HepG2 cells and determined its membrane topology by glycosylation mapping in vitro. The results demonstrate that URG7 is N-glycosylated and located to the endoplasmic reticulum membrane with an Nlumen-Ccytosol orientation. The results imply that the anti-apoptotic effect of URG7 could arise from the C-terminal cytosolic tail binding a pro-apoptotic signaling factor and retaining it to the endoplasmic reticulum membrane.
authors.affiliation: Department of Sciences, University of Basilicata, 85100 Potenza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ostuni
authors.forename: P
authors.initials: P
authors.lastname: Lara
authors.forename: M F
authors.initials: MF
authors.lastname: Armentano
authors.forename: R
authors.initials: R
authors.lastname: Miglionico
authors.forename: A M
authors.initials: AM
authors.lastname: Salvia
authors.forename: M
authors.initials: M
authors.lastname: Mönnich
authors.forename: M
authors.initials: M
authors.lastname: Carmosino
authors.forename: F M
authors.initials: FM
authors.lastname: Lasorsa
authors.forename: M
authors.initials: M
authors.lastname: Monné
authors.forename: I
authors.initials: I
authors.lastname: Nilsson
authors.forename: F
authors.initials: F
authors.lastname: Bisaccia
mesh_terms: D017209:Apoptosis; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D006031:Glycosylation; D056945:Hep G2 Cells; D006511:Hepatitis B Antigens / Q000235:genetics / Q000378:metabolism*; D006515:Hepatitis B virus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism* / Q000821:virology; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D015398:Signal Transduction
chemical_list: D006511:Hepatitis B Antigens; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C102029:ABCC6 protein, human
keywords: Apoptosis; Cellular localization; Endoplasmic reticulum; Hepatitis B x antigen; Topology; URG7