title: Identification of the ER-resident E3 ubiquitin ligase RNF145 as a novel LXR-regulated gene.
abstract: Cellular cholesterol metabolism is subject to tight regulation to maintain adequate levels of this central lipid molecule. Herein, the sterol-responsive Liver X Receptors (LXRs) play an important role owing to their ability to reduce cellular cholesterol load. In this context, identifying the full set of LXR-regulated genes will contribute to our understanding of their role in cholesterol metabolism. Using global transcriptional analysis we report here the identification of RNF145 as an LXR-regulated target gene. We demonstrate that RNF145 is regulated by LXRs in both human and mouse primary cells and cell lines, and in vivo in mice. Regulation of RNF145 by LXR depends on a functional LXR-element in its proximal promotor. Consistent with LXR-dependent regulation of Rnf145 we show that regulation is lost in macrophages and fibroblasts from Lxrαβ(-/-) mice, and also in vivo in livers of Lxrα(-/-) mice treated with the LXR synthetic ligand T0901317. RNF145 is closely related to RNF139/TRC8, an E3 ligase implicated in control of SREBP processing. However, silencing of RNF145 in HepG2 or HeLa cells does not impair SREBP1/2 processing and sterol-responsive gene expression in these cells. Similar to TRC8, we demonstrate that RNF145 is localized to the ER and that it possesses intrinsic E3 ubiquitin ligase activity. In summary, we report the identification of RNF145 as an ER-resident E3 ubiquitin ligase that is transcriptionally controlled by LXR.
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Emma C L
authors.initials: EC
authors.lastname: Cook
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Jessica K
authors.initials: JK
authors.lastname: Nelson
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.|Laboratory for integrative and systems physiology, EPFL, Lausanne, Switzerland.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Sorrentino
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Duco
authors.initials: D
authors.lastname: Koenis
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Martina
authors.initials: M
authors.lastname: Moeton
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Saskia
authors.initials: S
authors.lastname: Scheij
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Roelof
authors.initials: R
authors.lastname: Ottenhoff
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Boris
authors.initials: B
authors.lastname: Bleijlevens
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Anke
authors.initials: A
authors.lastname: Loregger
authors.affiliation: Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands.
authors.forename: Noam
authors.identifier: http://orcid.org/0000-0001-6935-7532
authors.initials: N
authors.lastname: Zelcer
mesh_terms: D000818:Animals; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D000071518:Liver X Receptors / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D011401:Promoter Regions, Genetic; D013449:Sulfonamides / Q000494:pharmacology; D014158:Transcription, Genetic; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D054875:Ubiquitination; D005466:Fluorocarbons; D000096926:Benzenesulfonamides
chemical_list: D002784:Cholesterol; D006845:Hydrocarbons, Fluorinated; D000071518:Liver X Receptors; D008565:Membrane Proteins; D013449:Sulfonamides; D044767:Ubiquitin-Protein Ligases; C000607305:RNF145 protein, mouse; C423915:T0901317; D005466:Fluorocarbons; D000096926:Benzenesulfonamides