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Clifford BL, Jarrett KE, Cheng J, Cheng A, Seldin M, Morand P, Lee R, Chen M, Baldan A, de Aguiar Vallim TQ, Tarling EJ. RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels. Circ Res 2023; 132:849-863. [PMID: 36876496 PMCID: PMC10065965 DOI: 10.1161/circresaha.122.321938] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/23/2023] [Indexed: 03/07/2023]
Abstract
BACKGROUND Removal of circulating plasma low-density lipoprotein cholesterol (LDL-C) by the liver relies on efficient endocytosis and intracellular vesicle trafficking. Increasing the availability of hepatic LDL receptors (LDLRs) remains a major clinical target for reducing LDL-C levels. Here, we describe a novel role for RNF130 (ring finger containing protein 130) in regulating plasma membrane availability of LDLR. METHODS We performed a combination of gain-of-function and loss-of-function experiments to determine the effect of RNF130 on LDL-C and LDLR recycling. We overexpressed RNF130 and a nonfunctional mutant RNF130 in vivo and measured plasma LDL-C and hepatic LDLR protein levels. We performed in vitro ubiquitination assays and immunohistochemical staining to measure levels and cellular distribution of LDLR. We supplement these experiments with 3 separate in vivo models of RNF130 loss-of-function where we disrupted Rnf130 using either ASO (antisense oligonucleotides), germline deletion, or AAV CRISPR (adeno-associated virus clustered regularly interspaced short palindromic repeats) and measured hepatic LDLR and plasma LDL-C. RESULTS We demonstrate that RNF130 is an E3 ubiquitin ligase that ubiquitinates LDLR resulting in redistribution of the receptor away from the plasma membrane. Overexpression of RNF130 decreases hepatic LDLR and increases plasma LDL-C levels. Further, in vitro ubiquitination assays demonstrate RNF130-dependent regulation of LDLR abundance at the plasma membrane. Finally, in vivo disruption of Rnf130 using ASO, germline deletion, or AAV CRISPR results in increased hepatic LDLR abundance and availability and decreased plasma LDL-C levels. CONCLUSIONS Our studies identify RNF130 as a novel posttranslational regulator of LDL-C levels via modulation of LDLR availability, thus providing important insight into the complex regulation of hepatic LDLR protein levels.
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Affiliation(s)
- Bethan L. Clifford
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
| | - Kelsey E. Jarrett
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
| | - Joan Cheng
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | - Angela Cheng
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | - Marcus Seldin
- Department of Biological Chemistry, University of California Irvine, CA, USA
| | - Pauline Morand
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | | | - Mary Chen
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO, USA
| | - Angel Baldan
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University, St. Louis, MO, USA
| | - Thomas Q. de Aguiar Vallim
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
| | - Elizabeth J. Tarling
- Department of Medicine, Division of Cardiology, University of California Los Angeles, CA, USA
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA, USA
- Lead contact
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Placental miR-340 mediates vulnerability to activity based anorexia in mice. Nat Commun 2018; 9:1596. [PMID: 29686286 PMCID: PMC5913294 DOI: 10.1038/s41467-018-03836-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 03/15/2018] [Indexed: 12/20/2022] Open
Abstract
Anorexia nervosa (AN) is a devastating eating disorder characterized by self-starvation that mainly affects women. Its etiology is unknown, which impedes successful treatment options leading to a limited chance of full recovery. Here, we show that gestation is a vulnerable window that can influence the predisposition to AN. By screening placental microRNA expression of naive and prenatally stressed (PNS) fetuses and assessing vulnerability to activity-based anorexia (ABA), we identify miR-340 as a sexually dimorphic regulator involved in prenatal programming of ABA. PNS caused gene-body hypermethylation of placental miR-340, which is associated with reduced miR-340 expression and increased protein levels of several target transcripts, GR, Cry2 and H3F3b. MiR-340 is linked to the expression of several nutrient transporters both in mice and human placentas. Using placenta-specific lentiviral transgenes and embryo transfer, we demonstrate the key role miR-340 plays in the mechanism involved in early life programming of ABA. Anorexia nervosa is characterised by self-starvation but its etiology is not completely understood. Here the authors describe how prenatal stress can induce activity-based anorexia in the offspring during early adulthood by upregulating miR-340 expression in the placenta that affects expression of nutrient transporters.
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Lehmann G, Udasin RG, Ciechanover A. On the linkage between the ubiquitin-proteasome system and the mitochondria. Biochem Biophys Res Commun 2016; 473:80-86. [DOI: 10.1016/j.bbrc.2016.03.055] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 03/14/2016] [Indexed: 12/20/2022]
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Argos M, Chen L, Jasmine F, Tong L, Pierce BL, Roy S, Paul-Brutus R, Gamble MV, Harper KN, Parvez F, Rahman M, Rakibuz-Zaman M, Slavkovich V, Baron JA, Graziano JH, Kibriya MG, Ahsan H. Gene-specific differential DNA methylation and chronic arsenic exposure in an epigenome-wide association study of adults in Bangladesh. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:64-71. [PMID: 25325195 PMCID: PMC4286273 DOI: 10.1289/ehp.1307884] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 10/15/2014] [Indexed: 05/20/2023]
Abstract
BACKGROUND Inorganic arsenic is one of the most common naturally occurring contaminants found in the environment. Arsenic is associated with a number of health outcomes, with epigenetic modification suggested as a potential mechanism of toxicity. OBJECTIVE Among a sample of 400 adult participants, we evaluated the association between arsenic exposure, as measured by blood and urinary total arsenic concentrations, and epigenome-wide white blood cell DNA methylation. METHODS We used linear regression models to examine the associations between arsenic exposure and methylation at each CpG site, adjusted for sex, age, and batch. Differentially methylated loci were subsequently examined in relation to corresponding gene expression for functional evidence of gene regulation. RESULTS In adjusted analyses, we observed four differentially methylated CpG sites with urinary total arsenic concentration and three differentially methylated CpG sites with blood arsenic concentration, based on the Bonferroni-corrected significance threshold of p < 1 × 10(-7). Methylation of PLA2G2C (probe cg04605617) was the most significantly associated locus in relation to both urinary (p = 3.40 × 10(-11)) and blood arsenic concentrations (p = 1.48 × 10(-11)). Three additional novel methylation loci-SQSTM1 (cg01225779), SLC4A4 (cg06121226), and IGH (cg13651690)--were also significantly associated with arsenic exposure. Further, there was evidence of methylation-related gene regulation based on gene expression for a subset of differentially methylated loci. CONCLUSIONS We observed significant associations between arsenic exposure and gene-specific differential white blood cell DNA methylation, suggesting that epigenetic modifications may be an important pathway underlying arsenic toxicity. The specific differentially methylated loci identified may inform potential pathways for future interventions.
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Affiliation(s)
- Maria Argos
- Department of Public Health Sciences, The University of Chicago, Chicago, Illinois, USA
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Nakamura N. The Role of the Transmembrane RING Finger Proteins in Cellular and Organelle Function. MEMBRANES 2011; 1:354-93. [PMID: 24957874 PMCID: PMC4021871 DOI: 10.3390/membranes1040354] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 11/24/2011] [Accepted: 12/05/2011] [Indexed: 01/08/2023]
Abstract
A large number of RING finger (RNF) proteins are present in eukaryotic cells and the majority of them are believed to act as E3 ubiquitin ligases. In humans, 49 RNF proteins are predicted to contain transmembrane domains, several of which are specifically localized to membrane compartments in the secretory and endocytic pathways, as well as to mitochondria and peroxisomes. They are thought to be molecular regulators of the organization and integrity of the functions and dynamic architecture of cellular membrane and membranous organelles. Emerging evidence has suggested that transmembrane RNF proteins control the stability, trafficking and activity of proteins that are involved in many aspects of cellular and physiological processes. This review summarizes the current knowledge of mammalian transmembrane RNF proteins, focusing on their roles and significance.
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Affiliation(s)
- Nobuhiro Nakamura
- Department of Biological Sciences, Tokyo Institute of Technology, 4259-B13 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
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Fiol DF, Sanmarti E, Lim AH, Kültz D. A novel GRAIL E3 ubiquitin ligase promotes environmental salinity tolerance in euryhaline tilapia. Biochim Biophys Acta Gen Subj 2010; 1810:439-45. [PMID: 21126558 DOI: 10.1016/j.bbagen.2010.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Revised: 11/14/2010] [Accepted: 11/17/2010] [Indexed: 11/24/2022]
Abstract
BACKGROUND Tilapia (Oreochromis mossambicus) are euryhaline fishes capable of tolerating large salinity changes. In a previous study aimed to identify genes involved in osmotolerance, we isolated an mRNA sequence with similarity to GRAIL (Gene Related to Anergy In Lymphocytes), which is a critical regulator of adaptive immunity and development. Tilapia GRAIL contains a PA (protease associated) domain and a C3H2C3 RING finger domain indicative of E3 ubiquitin ligase activity. SCOPE OF REVIEW Western blots analysis was used to assess GRAIL expression pattern and responses to hyperosmotic stress. Immunohistochemistry was used to reveal the cellular localization of GRAIL in gill epithelium. Overexpression in HEK293 T-Rex cells was used to functionally characterize tilapia GRAIL. Salinity stress causes strong up-regulation of both mRNA and protein levels of tilapia GRAIL in gill epithelium. Tissue distribution of GRAIL protein is mainly confined to gill epithelium, which is the primary tissue responsible for osmoregulation of teleost fishes. Overexpression of tilapia GRAIL in HEK293 cells increases cell survival (cell viability) while decreases apoptosis during salinity challenge. MAJOR CONCLUSIONS Our data indicate that tilapia GRAIL is a novel E3 ubiquitin ligase involved in osmotic stress signaling, which promotes environmental salinity tolerance by supporting gill cell function during hyperosmotic stress. GENERAL SIGNIFICANCE Involvement of tilapia GRAIL in the osmotic stress response suggests that GRAIL E3 ubiquitin ligases play a broader role in environmental stress responses, beyond their documented functions in adaptive immunity and development.
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Affiliation(s)
- Diego F Fiol
- Physiological Genomics Group, Department of Animal Sciences, University of California at Davis, CA 95616, USA
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Jin X, Cheng H, Chen J, Zhu D. RNF13: an emerging RING finger ubiquitin ligase important in cell proliferation. FEBS J 2010; 278:78-84. [PMID: 21078127 DOI: 10.1111/j.1742-4658.2010.07925.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Protein ubiquitination mediated by ubiquitin ligases plays a very important role in a wide spectrum of biological processes including development and disease pathogenesis. RING finger protein 13 (RNF13) is a recently identified ubiquitin ligase which contains an N-terminal protease-associated domain and a C-terminal RING finger domain separated by a transmembrane region. RNF13 is an evolutionarily conserved protein. Most interestingly, RNF13 expression is developmentally regulated during myogenesis and is upregulated in various human tumors. These data suggest that RNF13, acting as an ubiquitin ligase, might have profound biological functions during development and disease. This minireview summarizes recent work on RNF13 functions related to cell proliferation, differentiation and cancer development.
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Affiliation(s)
- Xianglan Jin
- National Laboratory of Medical Molecular Biology, Tsinghua University, Beijing, China
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Bocock JP, Carmicle S, Madamba E, Erickson AH. Nuclear targeting of an endosomal E3 ubiquitin ligase. Traffic 2010; 11:756-66. [PMID: 20230530 DOI: 10.1111/j.1600-0854.2010.01060.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Ring finger protein 13 (RNF13) is an E3 ubiquitin ligase embedded in endosome membranes. The protein undergoes constitutive post-translational proteolysis, making its detection difficult unless cells are incubated with a proteasome inhibitor to allow biosynthetic forms to accumulate. When cells were treated with phorbol 12-myristate 13-acetate (PMA), RNF13 avoided proteolysis. A similar stabilization was seen on ionomycin treatment of cells. Drug treatment stabilized both the full-length protein and a membrane-embedded C-terminal fragment generated following ectodomain shedding. Immunofluorescence staining revealed that PMA treatment caused the protein to accumulate in recycling endosomes, where it colocalized with transferrin receptor, and on the inner nuclear membrane, where it colocalized with lamin B. Expression of dominant-negative Rab11 inhibited nuclear localization, suggesting RNF13 was targeted to the inner nuclear membrane through recycling endosomes. New protein synthesis was necessary for this targeting. Nuclear localization was confirmed by immunoelectron microscopy and by purification of the inner nuclear membrane. Stress-induced transport of an endosomal protein to the inner nuclear membrane is a novel mechanism for introduction of regulatory proteins to the DNA environment. RNF13, with its ubiquitin ligase-active RING domain, has the potential to turn over key nuclear proteins in response to signals received at the plasma membrane.
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Affiliation(s)
- Jeffrey P Bocock
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
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Bocock JP, Carmicle S, Chhotani S, Ruffolo MR, Chu H, Erickson AH. The PA-TM-RING protein RING finger protein 13 is an endosomal integral membrane E3 ubiquitin ligase whose RING finger domain is released to the cytoplasm by proteolysis. FEBS J 2009; 276:1860-77. [PMID: 19292867 DOI: 10.1111/j.1742-4658.2009.06913.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PA-TM-RING proteins have an N-terminal protease-associated domain, a structure found in numerous proteases and implicated in protein binding, and C-terminal RING finger and PEST domains. Homologous proteins include GRAIL (gene related to anergy in leukocytes), which controls T-cell anergy, and AtRMR1 (receptor homology region-transmembrane domain-RING-H2 motif protein), a plant protein storage vacuole sorting receptor. Another family member, chicken RING zinc finger (C-RZF), was identified as being upregulated in embryonic chicken brain cells grown in the presence of tenascin-C. Despite algorithm predictions that the cDNA encodes a signal peptide and transmembrane domain, the protein was found in the nucleus. We showed that RING finger protein 13 (RNF13), the murine homolog of C-RZF, is a type I integral membrane protein localized in the endosomal/lysosomal system. By quantitative real-time RT-PCR analysis, we demonstrated that expression of RNF13 is increased in adult relative to embryonic mouse tissues and is upregulated in B35 neuroblastoma cells stimulated to undergo neurite outgrowth. We found that RNF13 is very labile, being subject to extensive proteolysis that releases both the protein-associated domain and the RING domain from the membrane. By analyzing microsomes, we showed that the ectodomain is shed into the lumen of vesicles, whereas the C-terminal half, which possesses the RING finger, is released to the cytoplasm. This C-terminal fragment of RNF13 has the ability to mediate ubiquitination. Proteolytic release of RNF13 from a membrane anchor thus provides unique spatial and temporal regulation that has not been previously described for an endosomal E3 ubiquitin ligase.
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Affiliation(s)
- Jeffrey P Bocock
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
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Guais A, Siegrist S, Solhonne B, Jouault H, Guellaën G, Bulle F. h-Goliath, paralog of GRAIL, is a new E3 ligase protein, expressed in human leukocytes. Gene 2006; 374:112-20. [PMID: 16549277 DOI: 10.1016/j.gene.2006.01.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 01/19/2006] [Accepted: 01/25/2006] [Indexed: 11/28/2022]
Abstract
In Drosophila, the RING finger protein d-Goliath was originally identified as a transcription factor involved in the embryo mesoderm formation [Bouchard, M.L., Cote, S., 1993. The Drosophila melanogaster developmental gene g1 encodes a variant zinc-finger-motif protein. Gene 125, 205-209]. In mouse, the m-Goliath mRNA level was shown to be increased in growth factor withdrawal-induced apoptosis of myeloid cells [Baker, S.J., Reddy, E.P., 2000. Cloning of murine G1RP, a novel gene related to Drosophila melanogaster g1. Gene 248, 33-40]. Due to its putative function of transcription factor in apoptosis, we cloned the human cDNA for h-Goliath and characterized the expression of the protein in blood and bone marrow cells. The human protein of 419 aa (44 kDa) contains a protease-associated domain, a transmembrane domain and a RING-H2 motif. This structure classifies h-Goliath as a new member of a human family of ubiquitin ligases with GRAIL (gene related to anergy in lymphocytes) as founder. This E3 ligase controls the development of T cell clonal anergy by ubiquitination [Anandasabapathy, N., Ford, G.S., Bloom, D., Holness, C., Paragas, V., Seroogy, C., Skrenta, H., Hollenhorst, M., Fathman, C.G., Soares, L., 2003. GRAIL: an E3 ubiquitin ligase that inhibits cytokine gene transcription is expressed in anergic CD4+ T cells. Immunity 18, 535-547]. In vitro ubiquitination studies support the E3 ubiquitin ligase activity of h-Goliath. In human, the protein is expressed under 3 isoforms, a major one at 28 kDa and two others at 46 and 55 kDa. These proteins come from a common precursor (44 kDa) as we observed using in vitro transcription-translation. Using immunohistochemistry on blood or bone marrow smears, of healthy or leukemia samples, we found that the protein expression was restricted to the cytoplasm of progenitors and fully differentiated leukocyte populations. We did not observe any modification of h-Goliath expression or localization in leukemia. In these cells, this new E3 ubiquitin ligase protein does not seem associated with a differentiation state of the cell or with apoptosis.
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Affiliation(s)
- Adeline Guais
- INSERM U581, Hôpital H. Mondor, 94010 Créteil, France
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