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Temporal characterization of the non-structural Adenovirus type 2 proteome and phosphoproteome using high-resolving mass spectrometry. Virology 2017; 511:240-248. [PMID: 28915437 DOI: 10.1016/j.virol.2017.08.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/21/2017] [Accepted: 08/25/2017] [Indexed: 01/20/2023]
Abstract
The proteome and phosphoproteome of non-structural proteins of Adenovirus type 2 (Ad2) were time resolved using a developed mass spectrometry approach. These proteins are expressed by the viral genome and important for the infection process, but not part of the virus particle. We unambiguously confirm the existence of 95% of the viral proteins predicted to be encoded by the viral genome. Most non-structural proteins peaked in expression at late time post infection. We identified 27 non-redundant sites of phosphorylation on seven different non-structural proteins. The most heavily phosphorylated protein was the DNA binding protein (DBP) with 15 different sites. The phosphorylation occupancy rate could be calculated and monitored with time post infection for 15 phosphorylated sites on various proteins. In the DBP, phosphorylations with time-dependent relation were observed. The findings show the complexity of the Ad2 non-structural proteins and opens up a discussion for potential new drug targets.
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2
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Ramke M, Lee JY, Dyer DW, Seto D, Rajaiya J, Chodosh J. The 5'UTR in human adenoviruses: leader diversity in late gene expression. Sci Rep 2017; 7:618. [PMID: 28377580 PMCID: PMC5429599 DOI: 10.1038/s41598-017-00747-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 03/14/2017] [Indexed: 01/05/2023] Open
Abstract
Human adenoviruses (HAdVs) shut down host cellular cap-dependent mRNA translation while initiating the translation of viral late mRNAs in a cap-independent manner. HAdV 5′ untranslated regions (5′UTRs) are crucial for cap-independent initiation, and influence mRNA localization and stability. However, HAdV translational regulation remains relatively uncharacterized. The HAdV tripartite leader (TPL), composed of three introns (TPL 1–3), is critical to the translation of HAdV late mRNA. Herein, we annotated and analyzed 72 HAdV genotypes for the HAdV TPL and another previously described leader, the i-leader. Using HAdV species D, type 37 (HAdV-D37), we show by reverse transcription PCR and Sanger sequencing that mRNAs of the HAdV-D37 E3 transcription unit are spliced to the TPL. We also identified a polycistronic mRNA for RID-α and RID-β. Analysis of the i-leader revealed a potential open reading frame within the leader sequence and the termination of this potential protein in TPL3. A potential new leader embedded within the E3 region was also detected and tentatively named the j-leader. These results suggest an underappreciated complexity of post-transcriptional regulation, and the importance of HAdV 5′UTRs for precisely coordinated viral protein expression along the path from genotype to phenotype.
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Affiliation(s)
- Mirja Ramke
- Howe Laboratory, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 243 Charles Street, Boston, Massachusetts, USA
| | - Jeong Yoon Lee
- Howe Laboratory, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 243 Charles Street, Boston, Massachusetts, USA
| | - David W Dyer
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Donald Seto
- Bioinformatics and Computational Biology Program, School of Systems Biology, George Mason University, Manassas, Virginia, USA
| | - Jaya Rajaiya
- Howe Laboratory, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 243 Charles Street, Boston, Massachusetts, USA.
| | - James Chodosh
- Howe Laboratory, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, 243 Charles Street, Boston, Massachusetts, USA.
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Zhao H, Chen M, Pettersson U. A new look at adenovirus splicing. Virology 2014; 456-457:329-41. [DOI: 10.1016/j.virol.2014.04.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 01/23/2014] [Accepted: 04/03/2014] [Indexed: 10/25/2022]
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Abstract
Genes within the E3 transcription unit of human adenoviruses modulate host immune responses to infection. A comprehensive genomics and bioinformatics analysis of the E3 transcription unit for 38 viruses within human adenovirus species D (HAdV-D) revealed distinct and surprising patterns of homologous recombination. Homologous recombination was identified in open reading frames for E3 CR1α, CR1β, and CR1γ, similar to that previously observed with genes encoding the three major structural capsid proteins, the penton base, hexon, and fiber.
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Shah AH, Cianciola NL, Mills JL, Sönnichsen FD, Carlin C. Adenovirus RIDalpha regulates endosome maturation by mimicking GTP-Rab7. ACTA ACUST UNITED AC 2007; 179:965-80. [PMID: 18039930 PMCID: PMC2099200 DOI: 10.1083/jcb.200702187] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The small guanosine triphosphatase Rab7 regulates late endocytic trafficking. Rab7-interacting lysosomal protein (RILP) and oxysterol-binding protein-related protein 1L (ORP1L) are guanosine triphosphate (GTP)-Rab7 effectors that instigate minus end-directed microtubule transport. We demonstrate that RILP and ORP1L both interact with the group C adenovirus protein known as receptor internalization and degradation alpha (RIDalpha), which was previously shown to clear the cell surface of several membrane proteins, including the epidermal growth factor receptor and Fas (Carlin, C.R., A.E. Tollefson, H.A. Brady, B.L. Hoffman, and W.S. Wold. 1989. Cell. 57:135-144; Shisler, J., C. Yang, B. Walter, C.F. Ware, and L.R. Gooding. 1997. J. Virol. 71:8299-8306). RIDalpha localizes to endocytic vesicles but is not homologous to Rab7 and is not catalytically active. We show that RIDalpha compensates for reduced Rab7 or dominant-negative (DN) Rab7(T22N) expression. In vitro, Cu(2+) binding to RIDalpha residues His75 and His76 facilitates the RILP interaction. Site-directed mutagenesis of these His residues results in the loss of RIDalpha-RILP interaction and RIDalpha activity in cells. Additionally, expression of the RILP DN C-terminal region hinders RIDalpha activity during an acute adenovirus infection. We conclude that RIDalpha coordinates recruitment of these GTP-Rab7 effectors to compartments that would ordinarily be perceived as early endosomes, thereby promoting the degradation of selected cargo.
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Affiliation(s)
- Ankur H Shah
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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6
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Chin YR, Horwitz MS. Adenovirus RID complex enhances degradation of internalized tumour necrosis factor receptor 1 without affecting its rate of endocytosis. J Gen Virol 2006; 87:3161-3167. [PMID: 17030848 DOI: 10.1099/vir.0.82001-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The receptor internalization and degradation (RID) complex of adenovirus plays an important role in modulating the immune response by downregulating the surface levels of tumour necrosis factor receptor 1 (TNFR1), thereby inhibiting NF-κB activation. Total cellular content of TNFR1 is also reduced in the presence of RID, which can be inhibited by treatment with lysosomotropic agents. In this report, surface biotinylation experiments revealed that, although RID and TNFR1 were able to form a complex on the cell surface, the rate of TNFR1 endocytosis was not affected by RID. However, the degradation of internalized TNFR1 was enhanced significantly in the presence of RID. Therefore, these data suggest that RID downregulates TNFR1 levels by altering the fate of internalized TNFR1 that becomes associated with RID at the plasma membrane, probably by promoting its sorting into endosomal/lysosomal degradation compartments.
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Affiliation(s)
- Y Rebecca Chin
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Forchheimer Building, Room 411, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Marshall S Horwitz
- Division of Infectious Diseases, Department of Pediatrics, Albert Einstein College of Medicine, Forchheimer Building, Room 411, 1300 Morris Park Avenue, Bronx, NY 10461, USA
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Forchheimer Building, Room 411, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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7
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Chin YR, Horwitz MS. Mechanism for removal of tumor necrosis factor receptor 1 from the cell surface by the adenovirus RIDalpha/beta complex. J Virol 2005; 79:13606-17. [PMID: 16227281 PMCID: PMC1262606 DOI: 10.1128/jvi.79.21.13606-13617.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Proteins encoded in adenovirus early region 3 have important immunoregulatory properties. We have recently shown that the E3-10.4K/14.5K (RIDalpha/beta) complex downregulates tumor necrosis factor receptor 1 (TNFR1) expression at the plasma membrane. To study the role of the RIDbeta tyrosine sorting motif in the removal of surface TNFR1, tyrosine 122 on RIDbeta was mutated to alanine or phenylalanine. Both RIDbeta mutations not only abolished the downregulation of surface TNFR1 but paradoxically increased surface TNFR1 levels. RID also downregulates other death receptors, such as FAS; however, surface FAS expression was not increased by RIDbeta mutants, suggesting that regulation of TNFR1 and that of FAS by RID are mechanistically different. In the mixing experiments, the wild-type (WT) RID-mediated TNFR1 downregulation was partially inhibited in the presence of RIDbeta mutants, indicating that the mutants compete for TNFR1 access. Indeed, an association between RIDbeta and TNFR1 was shown by coimmunoprecipitation. In contrast, the mutants did not affect the WT RID-induced downregulation of FAS. These differential effects support a model in which RID associates with TNFR1 on the plasma membrane, whereas RID probably associates with FAS in a cytoplasmic compartment. By using small interfering RNA against the mu2 subunit of adaptor protein 2, dominant negative dynamin construct K44A, and the lysosomotropic agents bafilomycin A1 and ammonium chloride, we also demonstrated that surface TNFR1 was internalized by RID by a clathrin-dependent process involving mu2 and dynamin, followed by degradation of TNFR1 via an endosomal/lysosomal pathway.
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Affiliation(s)
- Y Rebecca Chin
- Department of Microbiology and Immunology, Forchheimer Building, Room 411, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA.
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8
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Toth K, Doronin K, Kuppuswamy M, Ward P, Tollefson AE, Wold WSM. Adenovirus immunoregulatory E3 proteins prolong transplants of human cells in immunocompetent mice. Virus Res 2005; 108:149-59. [PMID: 15681065 DOI: 10.1016/j.virusres.2004.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 09/01/2004] [Accepted: 09/01/2004] [Indexed: 11/26/2022]
Abstract
The majority of proteins encoded in the early 3 (E3) region of human subgroup C adenoviruses function to modulate the host immune response. For example, gp19K, one of these E3 proteins, prevents the major histocompatibility complex type I (MHC-I) from presenting viral antigens on the surface of the infected cell. Other E3 proteins, such as the RID and 14.7K proteins, counteract the effector phase of the cellular immune response. In order to study further the effects of these proteins, we constructed an E1-/E3- adenovirus vector, Ad/E3, that contains all the E3 genes with the exception of the cytolytic adp gene, inserted into the deleted E1 region. The transcription of the E3 genes in this vector is driven by a CMV promoter in place of the native E3 promoter. Ad/E3 expressed close to wild-type adenovirus levels of all E3 proteins, and these proteins appear to function normally in cell culture. For example, in Ad/E3-infected cells, surface expression of MHC-I was down-regulated, as was cell surface display of death receptors Fas and TRAIL Receptor 1. A human cell line of lung origin (A549), which was rapidly rejected after transplantation into C57BL/6 mice, was protected for an extended time from the host immune response after infection with an Ad/E3, and went through a number of divisions in immunocompetent mice. These latter results indicate that the E3 proteins protect cells from destruction by the immune system.
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Affiliation(s)
- Karoly Toth
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1402 South Grand Blvd., Saint Louis, MO 63104, USA.
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9
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Lichtenstein DL, Doronin K, Toth K, Kuppuswamy M, Wold WSM, Tollefson AE. Adenovirus E3-6.7K protein is required in conjunction with the E3-RID protein complex for the internalization and degradation of TRAIL receptor 2. J Virol 2004; 78:12297-307. [PMID: 15507617 PMCID: PMC525093 DOI: 10.1128/jvi.78.22.12297-12307.2004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Accepted: 06/23/2004] [Indexed: 11/20/2022] Open
Abstract
Adenoviruses (Ads) encode several proteins within the early region 3 (E3) transcription unit that help protect infected cells from elimination by the immune system. Among these immunomodulatory proteins, the receptor internalization and degradation (RID) protein complex, which is composed of the RIDalpha (formerly E3-10.4K) and RIDbeta (formerly E3-14.5K) subunits, stimulates the internalization and degradation of certain members of the tumor necrosis factor (TNF) receptor superfamily, thus blocking apoptosis initiated by Fas and TNF-related apoptosis-inducing ligand (TRAIL). The experiments reported here show that TRAIL receptor 2 (TR2) is cleared from the cell surface in Ad-infected cells. Virus mutants containing deletions that span E3 were used to show that the RID and E3-6.7K proteins are both necessary for the internalization and degradation of TR2, whereas only the RID protein is required for TRAIL receptor 1 downregulation. In addition, replication-defective Ad vectors that express individual E3 proteins were used to establish that the RID and E3-6.7K proteins are sufficient to clear TR2. These data demonstrate that E3-6.7K is an important component of the antiapoptosis arsenal encoded by the E3 transcription unit of subgroup C Ads.
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Affiliation(s)
- Drew L Lichtenstein
- Department of Molecular Microbiology and Immunology, School of Medicine, Saint Louis University, 1402 South Grand Blvd., St. Louis, MO 63104, USA
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Lichtenstein DL, Toth K, Doronin K, Tollefson AE, Wold WSM. Functions and mechanisms of action of the adenovirus E3 proteins. Int Rev Immunol 2004; 23:75-111. [PMID: 14690856 DOI: 10.1080/08830180490265556] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In the evolutionary battle between viruses and their hosts, viruses have armed themselves with weapons to defeat the host's attacks on infected cells. Various proteins encoded in the adenovirus (Ad) E3 transcription unit protect cells from killing mediated by cytotoxic T cells and death-inducing cytokines such as tumor necrosis factor (TNF), Fas ligand, and TNF-related apoptosis-inducing ligand (TRAIL). The viral protein E3-gp19 K blocks MHC class-I-restricted antigen presentation, which diminishes killing by cytotoxic T cells. The receptor internalization and degradation (RID) complex (formerly E3-10.4 K/14.5 K) stimulates the clearance from the cell surface and subsequent degradation of the receptors for Fas ligand and TRAIL, thereby preventing the action of these important immune mediators. RID also downmodulates the epidermal growth factor receptor (EGFR), although what role, if any, this function has in immune regulation is uncertain. In addition, RID antagonizes TNF-mediated apoptosis and inflammation through a mechanism that does not primarily involve receptor downregulation. E3-6.7 K functions together with RID in downregulating some TRAIL receptors and may block apoptosis independently of other E3 proteins. Furthermore, E3-14.7 K functions as a general inhibitor of TNF-mediated apoptosis and blocks TRAIL-induced apoptosis. Finally, after expending great effort to maintain cell viability during the early part of the virus replication cycle, Ads lyse the cell to allow efficient virus release and dissemination. To perform this task subgroup C Ads synthesize a protein late in infection named ADP (formerly E3-11.6 K) that is required for efficient virus release. This review focuses on recent experiments aimed at discovering the mechanism of action of these critically important viral proteins.
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Affiliation(s)
- Drew L Lichtenstein
- Department of Molecular Microbiology and Immunology, Saint Louis University Health Sciences Center, St. Louis, Missouri 63104, USA
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11
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Zanardi TA, Yei S, Lichtenstein DL, Tollefson AE, Wold WSM. Distinct domains in the adenovirus E3 RIDalpha protein are required for degradation of Fas and the epidermal growth factor receptor. J Virol 2003; 77:11685-96. [PMID: 14557654 PMCID: PMC229367 DOI: 10.1128/jvi.77.21.11685-11696.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adenovirus (Ad) types 2 and 5 encode at least five proteins within the E3 transcription unit that help the virus evade the immune system. Two such proteins, RIDalpha (formerly E3-10.4K) and RIDbeta (formerly E3-14.5K), form the RID (receptor internalization and degradation) complex (formerly E3-10.4K/14.5K). RID mediates clearance from the cell surface and lysosomal degradation of a number of important members in the tumor necrosis factor receptor (TNFR) superfamily and the receptor tyrosine kinase receptor family. Affected receptors include Fas, TRAIL (TNF-related apoptosis-inducing ligand) receptor 1 (TR1), TR2, and epidermal growth factor receptor (EGFR). Degradation of Fas and TRAIL receptors protects Ad-infected cells from apoptosis. To investigate the mechanism of action of RIDalpha, 14 mutant RIDalpha proteins, each containing a three- to five-amino-acid deletion, were constructed and then expressed from the E3 region of a replication-competent recombinant Ad in the same context as wild-type RIDalpha. Each mutant protein was characterized with regard to five physical properties associated with wild-type RIDalpha, namely, protein stability, proteolytic cleavage, insertion into the membrane, complex formation with RIDbeta, and transport to the cell surface. Additionally, the mutant proteins were tested for their ability to mediate internalization and degradation of EGFR and Fas and to protect cells from Fas-mediated apoptosis. The majority of mutant RIDalpha proteins (8 out of 14) were physically similar to wild-type RIDalpha. With regard to functional characteristics, the cytoplasmic domain of RIDalpha is largely unimportant for receptor internalization and degradation and the extracellular domain of RIDalpha is important for down-regulation of EGFR but not Fas.
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Affiliation(s)
- Tom A Zanardi
- Department of Molecular Microbiology and Immunology, Saint Louis University Health Sciences Center, St. Louis, Missouri 63104, USA
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12
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Lichtenstein DL, Krajcsi P, Esteban DJ, Tollefson AE, Wold WSM. Adenovirus RIDbeta subunit contains a tyrosine residue that is critical for RID-mediated receptor internalization and inhibition of Fas- and TRAIL-induced apoptosis. J Virol 2002; 76:11329-42. [PMID: 12388693 PMCID: PMC136796 DOI: 10.1128/jvi.76.22.11329-11342.2002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The adenovirus-encoded receptor internalization and degradation (RID) protein (previously named E3-10.4K/14.5K), which is composed of RIDalpha and RIDbeta subunits, down-regulates a number of cell surface receptors in the tumor necrosis factor (TNF) receptor superfamily, namely Fas, TRAIL receptor 1, and TRAIL receptor 2. Down-regulation of these "death" receptors protects adenovirus-infected cells from apoptosis induced by the death receptor ligands Fas ligand and TRAIL. RID also down-regulates certain tyrosine kinase cell surface receptors, especially the epidermal growth factor receptor (EGFR). RID-mediated Fas and EGFR down-regulation occurs via endocytosis of the receptors into endosomes followed by transport to and degradation within lysosomes. However, the molecular interactions underlying this function of RID are unknown. To investigate the molecular determinants of RIDbeta that are involved in receptor down-regulation, mutations within the cytoplasmic tail of RIDbeta were constructed and the mutant proteins were analyzed for their capacity to internalize and degrade Fas and EGFR and to protect cells from death receptor ligand-induced apoptosis. The results demonstrated the critical nature of a tyrosine residue near the RIDbeta C terminus; mutation of this residue to alanine abolished RID function. Mutating the tyrosine to phenylalanine did not abolish the function of RID, arguing that phosphorylation of the tyrosine is not required for function. These data suggest that this tyrosine residue forms part of a tyrosine-based sorting signal (Yxxphi). Additional mutations that target another potential sorting motif and several possible protein-protein interaction motifs had no discernible effect on RID function. It was also demonstrated that mutation of serine 116 to alanine eliminated phosphorylation of RIDbeta but did not affect any of the functions of RID that were examined. These results suggest a model in which the tyrosine-based sorting signal in RID plays a role in RID's ability to down-regulate receptors.
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Affiliation(s)
- Drew L Lichtenstein
- Department of Molecular Microbiology and Immunology, Saint Louis University Health Sciences Center, St. Louis, Missouri 63104, USA
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McNees AL, Garnett CT, Gooding LR. The adenovirus E3 RID complex protects some cultured human T and B lymphocytes from Fas-induced apoptosis. J Virol 2002; 76:9716-23. [PMID: 12208950 PMCID: PMC136506 DOI: 10.1128/jvi.76.19.9716-9723.2002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Human group C adenoviruses cause an acute infection in respiratory epithelia and establish a long-term or persistent infection, possibly in lymphocytes. The mechanism by which this persistence is maintained is unknown; however, it would require that persistently infected lymphocytes not be deleted. The adenovirus genome encodes proteins that prevent the immune system from eliminating the virus-infected cell, including the E3 receptor internalization and degradation (RID) complex. The RID complex prevents death of infected cells by blocking apoptosis initiated through death domain-containing receptors of the tumor necrosis factor receptor (TNFR) superfamily, including TNFR1 (L. R. Gooding, T. S. Ranheim, A. E. Tollefson, L. Aquino, P. Duerksen-Hughes, T. M. Horton, and W. S. Wold, J. Virol. 65:4114-4123, 1991), TNF-related apoptosis-inducing ligand receptors (TRAIL-R1 and -R2) (C. A. Benedict, P. S. Norris, T. I. Prigozy, J. L. Bodmer, J. A. Mahr, C. T. Garnett, F. Martinon, J. Tschopp, L. R. Gooding, and C. F. Ware, J. Biol. Chem. 276:3270-3278, 2001; A. E. Tollefson, K. Toth, K. Doronin, M. Kuppuswamy, O. A. Doronina, D. L. Lichtenstein, T. W. Hermiston, C. A. Smith, and W. S. Wold, J. Virol. 75:8875-8887, 2001), and Fas (J. Shisler, C. Yang, B. Walter, C. F. Ware, and L. R. Gooding, J. Virol. 71:8299-8306, 1997). Here, we test the ability of RID to protect human lymphocytes from apoptosis induced by ligation of Fas, a mechanism important for regulating lymphocyte populations. Using a retrovirus expressing RID to infect six human lymphocyte cell lines, we found that RID functions in the absence of other viral proteins to downregulate surface Fas on some, but not all, cell lines. Total cellular levels of Fas decrease as measured by Western blotting, and this loss of Fas correlates with protection from apoptosis induced by ligation of Fas in every cell line tested. Although in some cases, RID causes loss of only a fraction of surface Fas, the presence of RID completely blocks the immediate events downstream of Fas ligation (i.e., Fas-FADD association and caspase-8 cleavage) in susceptible cell lines. Nonetheless, the ability of RID to block Fas signaling is independent of the Fas signaling pathway used (type I or type II). Interestingly, among the four T-cell lines tested, RID caused loss of Fas in the two T-cell lines bearing a relatively immature phenotype, while having no activity in T cells with mature phenotypes. Collectively, these data suggest that RID functions to prevent apoptosis of some human lymphocytes by internalizing surface Fas receptors. It is possible that the expression of RID facilitates long-term infection by preventing Fas-mediated deletion of persistently infected lymphocytes.
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Affiliation(s)
- Adrienne L McNees
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Toth K, Kuppuswamy M, Doronin K, Doronina O, Lichtenstein D, Tollefson A, Wold W. Construction and characterization of E1-minus replication-defective adenovirus vectors that express E3 proteins from the E1 region. Virology 2002; 301:99-108. [PMID: 12359450 DOI: 10.1006/viro.2002.1580] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous research has indicated that the adenovirus protein complex named RID, derived from the E3 transcription unit, functions to remove the receptors named Fas/Apo1/CD95 (Fas) and epidermal growth factor receptor (EGFR) from the surface of cells. (The RID complex is composed of the RIDalpha and RIDbeta polypeptides, previously named 10.4K and 14.5K, respectively.) In response to RID, Fas and EGFR appear to be internalized into endosomes and degraded in lysosomes. Fas is a death receptor in the tumor necrosis factor (TNF) receptor superfamily. RID inhibits apoptosis via the Fas pathway, presumably because RID gets rid of Fas. Earlier work further showed that another adenovirus E3-coded protein, E3-14.7K, inhibits apoptosis induced by TNF. Most of the above studies have been conducted using viable virus mutants that lack one or more of the genes for RID, E3-14.7K, or E1B-19K (this protein, coded by the E1B transcription unit, also inhibits apoptosis via the TNF and Fas pathways). Some studies have also been conducted with the genes for RID or E3-14.7K transiently or stably transfected into cells. We now report a new approach to studying the E3 genes. We have constructed four E1-minus replication-defective vectors that have all the E3 genes deleted from their natural position and then reinserted, in different permutations, into the deleted E1 region under control of the cytomegalovirus immediate early promoter. Vector Ad/RID only has the genes for RIDalpha and RIDbeta. Vector Ad/14.7K only has the gene for E3-14.7K. Vector Ad/RID/14.7K only has the genes for RIDalpha, RIDbeta, and E3-14.7K. Vector Ad/E3 has all E3 genes, but there are two missense mutations in the gene for Adenovirus Death Protein. These vectors expressed RID and/or E3-14.7K, as expected. The RID-expressing vectors forced the internalization and degradation of Fas and EGFR, and they inhibited apoptosis induced through the Fas pathway. These vectors should be useful reagents to study the E3 proteins.
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Affiliation(s)
- Karoly Toth
- Department of Molecular Microbiology and Immunology, Saint Louis Unversity School of Medicine, Saint Louis, Missouri 63104, USA
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15
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Abstract
Adenoviruses (Ads) are endemic in the human population and the well-studied group C Ads typically cause an acute infection in the respiratory epithelium. A growing body of evidence suggests that these viruses also establish a persistent infection. The Ad genome encodes several proteins that counteract the host anti-viral mechanisms, which function to limit viral infections. This review describes the adenovirus immuno-regulatory proteins and how they function to block apoptosis of infected cells. In addition to facilitating the successful completion of the viral replication cycle and spread of progeny virus, these functions may help maintain the virus in a persistent state.
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Affiliation(s)
- Adrienne L McNees
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
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Tollefson AE, Toth K, Doronin K, Kuppuswamy M, Doronina OA, Lichtenstein DL, Hermiston TW, Smith CA, Wold WS. Inhibition of TRAIL-induced apoptosis and forced internalization of TRAIL receptor 1 by adenovirus proteins. J Virol 2001; 75:8875-87. [PMID: 11533151 PMCID: PMC114456 DOI: 10.1128/jvi.75.19.8875-8887.2001] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2001] [Accepted: 06/04/2001] [Indexed: 11/20/2022] Open
Abstract
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis through two receptors, TRAIL-R1 (also known as death receptor 4) and TRAIL-R2 (also known as death receptor 5), that are members of the TNF receptor superfamily of death domain-containing receptors. We show that human adenovirus type 5 encodes three proteins, named RID (previously named E3-10.4K/14.5K), E3-14.7K, and E1B-19K, that independently inhibit TRAIL-induced apoptosis of infected human cells. This conclusion was derived from studies using wild-type adenovirus, adenovirus replication-competent mutants that lack one or more of the RID, E3-14.7K, and E1B-19K genes, and adenovirus E1-minus replication-defective vectors that express all E3 genes, RID plus E3-14.7K only, RID only, or E3-14.7K only. RID inhibits TRAIL-induced apoptosis when cells are sensitized to TRAIL either by adenovirus infection or treatment with cycloheximide. RID induces the internalization of TRAIL-R1 from the cell surface, as shown by flow cytometry and indirect immunofluorescence for TRAIL-R1. TRAIL-R1 was internalized in distinct vesicles which are very likely to be endosomes and lysosomes. TRAIL-R1 is degraded, as indicated by the disappearance of the TRAIL-R1 immunofluorescence signal. Degradation was inhibited by bafilomycin A1, a drug that prevents acidification of vesicles and the sorting of receptors from late endosomes to lysosomes, implying that degradation occurs in lysosomes. RID was also shown previously to internalize and degrade another death domain receptor, Fas, and to prevent apoptosis through Fas and the TNF receptor. RID was shown previously to force the internalization and degradation of the epidermal growth factor receptor. E1B-19K was shown previously to block apoptosis through Fas, and both E1B-19K and E3-14.7K were found to prevent apoptosis through the TNF receptor. These findings suggest that the receptors for TRAIL, Fas ligand, and TNF play a role in limiting virus infections. The ability of adenovirus to inhibit killing through these receptors may prolong acute and persistent infections.
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Affiliation(s)
- A E Tollefson
- Department of Molecular Microbiology and Immunology, St. Louis University Health Sciences Center, St. Louis, Missouri 63104, USA
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17
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Hawkins LK, Johnson L, Bauzon M, Nye JA, Castro D, Kitzes GA, Young MD, Holt JK, Trown P, Hermiston TW. Gene delivery from the E3 region of replicating human adenovirus: evaluation of the 6.7 K/gp19 K region. Gene Ther 2001; 8:1123-31. [PMID: 11509942 DOI: 10.1038/sj.gt.3301507] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2000] [Accepted: 05/22/2001] [Indexed: 11/09/2022]
Abstract
The use of genetically engineered, replication-selective viruses to treat cancer is being realized with viruses such as ONYX-015, a human adenovirus that selectively destroys p53 mutant cancer cells. To enhance further the clinical efficacy of ONYX-015 and viruses like it, we have developed a novel gene delivery system for replicating adenoviruses. This system has two unique features. First, it uses the endogenous adenoviral gene expression machinery (promoter, splicing, polyadenylation) to drive transgene expression. Second, a single region or gene in the multi-gene E3 transcription unit is selectively substituted for by the therapeutic transgene(s). Analyzing various transgene substitutions for the 6.7 K/gp19 K region of E3, we demonstrate the following: (1) transgene expression in this system is predictable and mimics the substituted endogenous gene expression pattern, (2) expression of surrounding E3 genes can be retained, (3) the insertion site choice can effect both the transgene expression level and the viral life cycle, and, (4) expression levels from this system are superior to those generated from a replication-defective virus using the HCMV enhancer-promoter and this is dependent on viral DNA replication. This unique methodology has broad application to the rapidly evolving field of replicating virus-based therapies.
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Affiliation(s)
- L K Hawkins
- Onyx Pharmaceuticals, 3031 Research Drive, Richmond, CA 94806, USA
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18
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Idamakanti N, Reddy PS, Babiuk LA, Tikoo SK. Transcription mapping and characterization of 284R and 121R proteins produced from early region 3 of bovine adenovirus type 3. Virology 1999; 256:351-9. [PMID: 10191200 DOI: 10.1006/viro.1999.9626] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We established the transcription map of early region (E) 3 of bovine adenovirus 3 (BAV-3) by Northern blot, S1 nuclease protection assays, cDNA sequencing, and RT-PCR analysis. Five major classes of mRNAs were identified, which shared the 3' ends. Four classes of mRNAs transcribed from the E3 promoter also shared the 5' end, while one major class of mRNA transcribed from the major late promoter contained a tripartite leader sequence at the 5' end. These five transcripts have the potential to encode four proteins, namely 284R, 121R, 86R, and 82R. To identify the proteins, rabbit antiserum was prepared using a bacterial fusion protein encoding 284R or 121R protein. Serum against 284R immunoprecipitated protein of 26-32 kDa in in vitro translated and transcribed mRNA and three proteins of 48, 67, and 125 kDa from BAV-3-infected cells. Western blots and enzymatic digestions confirmed that the 284R protein is a glycoprotein, which contains only N-linked oligosaccharides, both high mannose (48 kDa) and complex types (67 kDa). Serum against 121R immunoprecipitated a protein of 14.5 kDa from in vitro translated and transcribed mRNA and BAV-3-infected cells. Although 121R protein shows limited sequence similarity to a 14.7-kDa protein of human adenovirus 5, the 284R protein appears to be unique to BAV-3. Since proteins encoded by the E3 region appear to influence adenovirus pathogenesis, the 284R protein may contribute to the unique pathogenic properties of BAV-3.
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Affiliation(s)
- N Idamakanti
- Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada
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19
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Abstract
Adenovirus is a human pathogen that infects mainly respiratory and gastrointestinal epithelia. While the pathology caused by this virus is generally not life threatening in immunocompetent individuals, there is a large literature describing its ability to establish a persistent infection. These persistent infections typically occur in apparently healthy individuals with no outward signs of disease. Such a long term and benign interaction between virus and immune system requires adenoviruses to dampen host antiviral effector mechanisms that would otherwise eliminate the virus and cause immune-mediated pathology to the host. Adenovirus devotes a significant portion of its genome to gene products whose sole function seems to be the modulation of host immune responses. This review focuses on what is currently understood about how these immunomodulatory mechanisms work and how they might play a role in maintaining the virus in a persistent state.
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Affiliation(s)
- J A Mahr
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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20
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Edwards KM, Davis JE, Browne KA, Sutton VR, Trapani JA. Anti-viral strategies of cytotoxic T lymphocytes are manifested through a variety of granule-bound pathways of apoptosis induction. Immunol Cell Biol 1999; 77:76-89. [PMID: 10101689 DOI: 10.1046/j.1440-1711.1999.00799.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cytotoxic T cells and natural killer cells together constitute a major defence against virus infection, through their ability to induce apoptotic death in infected cells. These cytolytic lymphocytes kill their targets through two principal mechanisms, and one of these, granule exocytosis, is essential for an effective in vivo immune response against many viruses. In recent years, the authors and other investigators have identified several distinct mechanisms that can induce death in a targeted cell. In the present article, it is postulated that the reason for this redundancy of lethal mechanisms is to deal with the array of anti-apoptotic molecules elaborated by viruses to extend the life of infected cells. The fate of such a cell therefore reflects the balance of pro-apoptotic (immune) and anti-apoptotic (viral) strategies that have developed over eons of evolutionary time.
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Affiliation(s)
- K M Edwards
- John Connell Laboratory, Austin Research Institute, Heidelberg, Victoria, Australia.
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21
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Adenovirus E3 Proteins: 14.7K, RID, and gp19K Inhibit Immune-Induced Cell Death; Adenovirus Death Protein Promotes Cell Death. ACTA ACUST UNITED AC 1998. [DOI: 10.1006/smvy.1998.0156] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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22
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Tollefson AE, Hermiston TW, Lichtenstein DL, Colle CF, Tripp RA, Dimitrov T, Toth K, Wells CE, Doherty PC, Wold WS. Forced degradation of Fas inhibits apoptosis in adenovirus-infected cells. Nature 1998; 392:726-30. [PMID: 9565035 DOI: 10.1038/33712] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
DNA viruses have evolved elaborate mechanisms to overcome host antiviral defences. In adenovirus-infected cells, programmed cell death (apoptosis) induced by the cytokine tumour necrosis factor (TNF) is inhibited by several adenovirus-encoded proteins. Occupation of the cell-surface receptor Fas, a member of the TNF-receptor superfamily that is expressed on most cell types, triggers apoptosis of that cell. Here we show that the adenovirus RID (for receptor internalization and degradation) protein complex, which is an inhibitor of TNF-induced apoptosis, mediates internalization of cell-surface Fas and its destruction inside lysosomes within the cell. Fas has not previously been shown to be internalized and then degraded. RID also mediates internalization of the receptor for epidermal growth factor, but it does not affect the transferrin receptor or class I antigens of the major histocompatibility complex. Removal of Fas from the surface of adenovirus-infected cells expressing RID may allow infected cells to resist Fas-mediated cell death and thus promote their survival.
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Affiliation(s)
- A E Tollefson
- Department of Molecular Microbiology and Immunology, St Louis University School of Medicine, Missouri 63104-1004, USA
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23
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Dimitrov T, Krajcsi P, Hermiston TW, Tollefson AE, Hannink M, Wold WS. Adenovirus E3-10.4K/14.5K protein complex inhibits tumor necrosis factor-induced translocation of cytosolic phospholipase A2 to membranes. J Virol 1997; 71:2830-7. [PMID: 9060638 PMCID: PMC191407 DOI: 10.1128/jvi.71.4.2830-2837.1997] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We have reported that three adenovirus (Ad) proteins, named E3-10.4K/14.5K, E3-14.7K, and E1B-19K, independently inhibit tumor necrosis factor (TNF)-induced apoptosis in Ad-infected cells. E3-10.4K/14.5K and E3-14.7K also inhibit TNF-induced release of arachidonic acid (AA). TNF-induced apoptosis and AA release are thought to require TNF-activation of the 85-kDa cytosolic phospholipase A2 (cPLA2). cPLA2 normally exists in a latent form in the cytosol; it is activated by phosphorylation by mitogen-activated protein kinase, and in the presence of agents that mobilize intracellular Ca2+, cPLA2 translocates to membranes where it cleaves AA from membrane phospholipids. We now report that TNF induces translocation of cPLA2 from the cytosol to membranes in Ad-infected human A549 cells and that E3-10.4K/14.5K but not E3-14.7K or E1B-19K is required to inhibit TNF-induced translocation of cPLA2. Ad infection also inhibited TNF-induced release of AA. Under the same conditions, Ad infection did not inhibit TNF-induced phosphorylation of cPLA2 or TNF activation of NFkappaB. Ad infection also inhibited cPLA2 translocation in response to the Ca2+ ionophore A23187 and to cycloheximide, but this inhibition did not require E3-10.4K/14.5K. Ad infection did not inhibit cPLA2 translocation in response to interleukin-1beta or platelet-derived growth factor. We propose that E3-10.4K/14.5K inhibits TNF-induced AA release and apoptosis by directly or indirectly inhibiting TNF-induced translocation of cPLA2 from the cytosol to membranes. AA formed by cPLA2 can be metabolized to prostaglandins, leukotrienes, and lipoxyns, molecules that amplify inflammation. E3-10.4K/14.5K probably functions in Ad infections to inhibit both TNF-induced apoptosis and inflammation.
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Affiliation(s)
- T Dimitrov
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine, Missouri 63104, USA
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24
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Krajcsi P, Dimitrov T, Hermiston TW, Tollefson AE, Ranheim TS, Vande Pol SB, Stephenson AH, Wold WS. The adenovirus E3-14.7K protein and the E3-10.4K/14.5K complex of proteins, which independently inhibit tumor necrosis factor (TNF)-induced apoptosis, also independently inhibit TNF-induced release of arachidonic acid. J Virol 1996; 70:4904-13. [PMID: 8763993 PMCID: PMC190440 DOI: 10.1128/jvi.70.8.4904-4913.1996] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Tumor necrosis factor (TNF) is an inflammatory cytokine that inhibits the replication of many viruses in cultured cells. We have reported that adenovirus (Ad) infection of TNF-resistant mouse cells renders them susceptible to lysis by TNF and that two sets of proteins encoded by the E3 transcription unit block TNF cytolysis. The E3 protein sets are named E3-14.7K (14,700 kDa) and E3-10.4K/14.5K (a complex of two proteins of 10,400 and 14,500 kDa). TNF activation of the 85-kDa cytosolic phospholipase A2 (cPLA2) is thought to be essential for TNF cytolysis (i.e.,TNF-induced apoptosis). Here we provide evidence that cPLA2 is important in the response of Ad-infected cells to TNF and that the mechanism by which E3-14.7K and E3-10.4K/14.5K inhibit TNF cytolysis is by inhibiting TNF activation of cPLA2. cPLA2 cleaves arachidonic acid (AA) specifically from membrane phospholipids; therefore, cPLA2 activity was measured by the release of 3H-AA from cells prelabeled with 3H-AA. Uninfected cells or cells infected with wild-type Ad were not lysed and did not release 3H-AA in response to TNF. In contrast, TNF treatment induced cytolysis and 3H-AA release in uninfected cells sensitized to TNF by treatment with cycloheximide and also in infected cells sensitized to TNF by expression of E1A. In C127 cells, in which either E3-14.7K or E3-10.4K/14.5K inhibits TNF cytolysis, either set of proteins inhibited TNF-induced release of 3H-AA. In C3HA cells, in which E3-14.7K but not E3-10.4K/14.5K prevents TNF cytolysis, E3-14.7K but not E3-10.4K/14.5K prevented TNF-induced release of 3H-AA. When five virus mutants with lesions in E3-14.7K were examined, there was a perfect correlation between a mutant's ability to inhibit both TNF-induced cytolysis and release of 3H-AA. E3-14.7K expressed in two stably transfected C127 cell lines prevented both TNF-cycloheximide-induced cytolysis and release of 3H-AA. The E3 proteins also prevented TNF-induced cytolysis and release of 3H-AA in mouse L929 cells, which are spontaneously sensitive to TNF. TNF cytolysis was blocked by dexamethasone, an inhibitor of PLA2 activity, and by nordihydroquaiaretic acid, which inhibits the metabolism of AA to the leukotrienes. Indomethacin, which blocks the formation of prostaglandins from AA, did not inhibit TNF cytolysis. The leukotrienes and prostaglandins are amplifiers of the inflammatory response. We propose that E3-14.7K and E3-10.4K/14.5K function independently in Ad infection to inhibit both cytolysis and inflammation induced by TNF.
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Affiliation(s)
- P Krajcsi
- Department of Molecular Microbiology and Immunology, St. Louis University Schoolof Medicine, Missouri 63104, USA
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25
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Sparer TE, Tripp RA, Dillehay DL, Hermiston TW, Wold WS, Gooding LR. The role of human adenovirus early region 3 proteins (gp19K, 10.4K, 14.5K, and 14.7K) in a murine pneumonia model. J Virol 1996; 70:2431-9. [PMID: 8642671 PMCID: PMC190086 DOI: 10.1128/jvi.70.4.2431-2439.1996] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Products of human adenovirus (Ad) early region 3 (E3) inhibit both specific (cytotoxic T lymphocytes [CTLs]) and innate (tumor necrosis factor alpha [TNF-alpha]) immune responses in vitro. The E3 gp19K protein prevents CTL recognition of Ad-infected fibroblasts by sequestering major histocompatibility complex class I proteins in the endoplasmic reticulum. E3 proteins 10.4K, 14.5K, and 14.7K function to protect infected cells from TNF-alpha cytolysis. To address the in vivo functions of these proteins, Ad mutants that lack the E3 genes encoding these proteins were inoculated intranasally into C57BL/10SnJ (H-2b) mice. Mutants that lack the gp19K gene failed to alter CTL generation or to affect Ad-induced pulmonary infiltrates. Since gamma interferon (IFN-gamma) is capable of overcoming gp19K suppression of CTL lysis in vitro, mice were depleted of IFN-gamma and inoculated with gp19K mutants. Even when IFN-gamma was depleted, gp19K was incapable of altering pulmonary lesions. These resuls are not in accord with the function of gp19K in vitro and suggest that gp19K does not affect immune recognition in vivo during an acute virus infection, yet they do not exclude the possibility that gp19K blocks immune recognition of Ad during a persistent infection. In contrast, when mice were inoculated with Ad mutants that lack the TNF resistance genes (14.7K and either 10.4K or 14.5K), there was a marked increase in alveolar infiltration and no change in the amounts of perivascular/peribronchiolar infiltration compared with wild-type-Ad-induced pathology. These findings demonstrate the importance of TNF susceptibility and TNF by-products for recruiting inflammatory cells into the lungs during Ad infections.
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Affiliation(s)
- T E Sparer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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26
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Stewart AR, Tollefson AE, Krajcsi P, Yei SP, Wold WS. The adenovirus E3 10.4K and 14.5K proteins, which function to prevent cytolysis by tumor necrosis factor and to down-regulate the epidermal growth factor receptor, are localized in the plasma membrane. J Virol 1995; 69:172-81. [PMID: 7983708 PMCID: PMC188561 DOI: 10.1128/jvi.69.1.172-181.1995] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The adenovirus type 2 and 5 E3 10,400- and 14,500-molecular-weight (10.4K and 14.5K) proteins are both required to protect some cell lines from lysis by tumor necrosis factor and to down-regulate the epidermal growth factor receptor. We have shown previously that both 10.4K and 14.5K are integral membrane proteins and that 14.5K is phosphorylated and O glycosylated. The 10.4K protein coimmunoprecipitates with 14.5K, indicating that the two proteins function as a complex. Here we show, using immunofluorescence and two different cell surface-labeling techniques, that both proteins are localized in the plasma membrane. In addition, we show that trafficking of each protein to the plasma membrane depends on concomitant expression of the other protein. Finally, neither protein could be immunoprecipitated from conditioned media, indicating that neither is secreted. Taken together, these results suggest that the plasma membrane is the site at which 10.4K and 14.5K function to inhibit cytolysis by tumor necrosis factor and to down-regulate the epidermal growth factor receptor.
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Affiliation(s)
- A R Stewart
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine, Missouri 63104
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27
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Affiliation(s)
- W S Wold
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine, MO 63104, USA
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28
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Kleiboeker SB. Sequence analysis of putative E3, pVIII, and fiber genomic regions of a porcine adenovirus. Virus Res 1994; 31:17-25. [PMID: 8165866 DOI: 10.1016/0168-1702(94)90067-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The complete nucleotide sequence of the putative early transcriptional region 3 (E3), plus the hexon-associated polypeptide VIII (pVIII) gene, and the N-terminus of the fiber protein gene of a porcine adenovirus isolate, NADC-1, was determined. The E3 region of NADC-1 was found to be 1879 bp and located between 80 and 85.8 map units. Eight open reading frames (ORFs) and three polyadenylation signals were identified in the r strand. The amino acid sequences predicted to be encoded by ORFs 1 and 8 were compared to the amino acid sequences of human adenovirus type 2 (Ad2) pVIII and fiber protein and found to be 60% and 55% similar, respectively. The amino acid sequence predicted to be encoded by ORF 4 was compared to the human Ad5 14.7 kDa protein and the C-terminus of the amino acid sequence predicted to be encoded by ORF 11 of the bovine Ad3 E3 region and found to be 36% and 41% similar, respectively. A potential signal sequence was identified in ORF 5.
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Affiliation(s)
- S B Kleiboeker
- Virology Swine Research Unit, National Animal Disease Center, USDA, Ames, IA 50010
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29
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Tufariello J, Cho S, Horwitz MS. The adenovirus E3 14.7-kilodalton protein which inhibits cytolysis by tumor necrosis factor increases the virulence of vaccinia virus in a murine pneumonia model. J Virol 1994; 68:453-62. [PMID: 8254756 PMCID: PMC236306 DOI: 10.1128/jvi.68.1.453-462.1994] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The 14.7-kilodalton protein (14.7K protein) encoded by the adenovirus (Ad) E3 region inhibits tumor necrosis factor alpha (TNF-alpha)-mediated lysis of cells in tissue culture experiments, but the relevance of this effect in vivo is incompletely understood. To examine the effect of the ability of the Ad 14.7K protein to block TNF lysis upon viral pathogenesis in a murine model, we cloned the 14.7K protein-encoding gene into vaccinia virus (VV), permitting its study in isolation from other Ad E3 immunomodulatory proteins. The gene for murine TNF-alpha was inserted into the same VV containing the 14.7K gene to ensure that each cell infected with the VV recombinant would express both the agonist (TNF) and its antagonist (14.7K). VV was utilized as the vector because it accommodates large and multiple inserts of foreign DNA with faithful, high-level expression of the protein products. In addition, infection of mice with VV induces disease with quantifiable morbidity, mortality, and virus replication. The results of intranasal infections of BALB/c mice with these VV recombinants indicate that the Ad 14.7K protein increases the virulence of VV carrying the TNF-alpha gene by reversing the attenuating effect of TNF-alpha on VV pathogenicity. This was demonstrated by increased mortality, pulmonary pathology, and viral titers in lung tissue following infection with VV coexpressing the 14.7K protein and TNF-alpha, compared with the control virus expressing TNF-alpha alone. These results suggest that the 14.7K protein, which is nonessential for Ad replication in tissue culture, is an immunoregulatory protein which functions in vivo to help counteract the antiviral effects of TNF-alpha.
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Affiliation(s)
- J Tufariello
- Department of Microbiology, Albert Einstein College of Medicine, Bronx, New York 10461
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30
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Ranheim TS, Shisler J, Horton TM, Wold LJ, Gooding LR, Wold WS. Characterization of mutants within the gene for the adenovirus E3 14.7-kilodalton protein which prevents cytolysis by tumor necrosis factor. J Virol 1993; 67:2159-67. [PMID: 8445725 PMCID: PMC240323 DOI: 10.1128/jvi.67.4.2159-2167.1993] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The 14,700-Da protein (14.7K protein) encoded by the E3 region of adenovirus has previously been shown to protect mouse cells from cytolysis by tumor necrosis factor (TNF). Delineating the sequences in the 14.7K protein that are required for this activity may provide insight into the mechanism of protection from TNF by 14.7K as well as the mechanism of TNF cytolysis. In the present study, we examined the ability of 14.7K mutants to protect cells from lysis by TNF. In-frame deletions as well as Cys-to-Ser mutations in the 14.7K gene were generated by site-directed mutagenesis and then built into the genome of a modified adenovirus type 5 (dl7001) that lacks all E3 genes. dl7001, which replicates to the same titers as does adenovirus type 5 in cultured cells, has the largest E3 deletion analyzed to date. 51Cr release was used to assay TNF cytolysis. Our results indicate that most mutations in the 14.7K gene result in a loss of function, suggesting that nearly the entire protein rather than a specific domain functions to prevent TNF cytolysis.
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Affiliation(s)
- T S Ranheim
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine, Missouri 63104
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31
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Kuivinen E, Hoffman BL, Hoffman PA, Carlin CR. Structurally related class I and class II receptor protein tyrosine kinases are down-regulated by the same E3 protein coded for by human group C adenoviruses. J Cell Biol 1993; 120:1271-9. [PMID: 8094718 PMCID: PMC2119731 DOI: 10.1083/jcb.120.5.1271] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Receptor tyrosine kinases (RTKs) are grouped into subcategories based on shared sequence and structural features. Human group C adenoviruses down-regulate EGF receptors, which are members of the class I family of RTKs, during the early stages of infection. Adenovirus appears to utilize a nonsaturable intracellular pathway since it causes EGF-R down-regulation even in cells that significantly overexpress EGF-R. Adenovirus-induced down-regulation is mediated by a small hydrophobic molecule coded for by the E3 early transcription region that has recently been localized to plasma membrane. Here we examine intracellular trafficking of other RTKs in adenovirus-infected cells, to better understand the molecular basis for the action of the E3 protein. Although p185c-neu, which is a class I RTK closely related to the EGF receptor, is down-regulated in cells expressing physiological concentrations of this molecule, it is not down-regulated in tumor cell lines that significantly overexpress p185c-neu. Cell surface receptors for insulin and IGF1, which are class II RTKs, are also reduced in cells expressing the E3 protein, although to a slightly lesser extent than the EGF receptor. Moreover, whereas EGF receptors are degraded between 3- and 9-h postinfection, insulin and IGF1 receptors are degraded between 6- and 12-h postinfection under identical conditions. In contrast to the class I and class II RTKs, there is no difference in the expression of the class III receptors for PDGF and aFGF in cells infected with a virus with an intact E3 region versus a virus mutant with an internal deletion in the relevant E3 gene. These results suggest that the E3 protein provides an internalization and degradative sorting signal for some class I and class II RTKs, although down-regulation of class II RTKs is somewhat less efficient. Molecular recognition of class I and class II RTKs during adenovirus infection may not be due strictly to amino acid structure, however, since EGF-R but not p185c-neu is down-regulated in cells where it is significantly overexpressed.
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Affiliation(s)
- E Kuivinen
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4970
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Scaria A, Tollefson AE, Saha SK, Wold WS. The E3-11.6K protein of adenovirus is an Asn-glycosylated integral membrane protein that localizes to the nuclear membrane. Virology 1992; 191:743-53. [PMID: 1448922 DOI: 10.1016/0042-6822(92)90250-s] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The 11,600 MW (101 amino acids; 11.6K) protein of adenovirus 2 (Ad2) is a protein of unknown function which is synthesized in low amounts during early stages of infection but in very high amounts at late stages. The 11.6K protein migrates as three major groupings of diffuse bands of ca. 14K, 21K, and 31K on SDS-PAGE, indicating that 11.6K undergoes post-translational modification. We show here that 11.6K is Asn-glycosylated with complex (endo H-resistant) oligosaccharides and that 11.6K is an integral membrane protein. Immunofluorescence indicated that 11.6K initially is associated with the endoplasmic reticulum and Golgi apparatus and that it ultimately localizes to the nuclear membrane. The 11.6K protein is predicted to have a single signal-anchor sequence at residues 41-62 and only one potential Asn-linked glycosylation site at residue 14; thus, 11.6K must be oriented in the membranes with its NH2-terminus in the lumen and its COOH-terminus in the cytoplasm. The signal-anchor and glycosylation features of 11.6K are preserved in Ad2 and Ad5 (group C), and in Ad3 and Ad7 (group B), but the sequence of 11.6K is more diverged among these serotypes than is the sequence of most other adenovirus proteins.
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Affiliation(s)
- A Scaria
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine, Missouri 63104
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33
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Mei YF, Wadell G. The nucleotide sequence of adenovirus type 11 early 3 region: comparison of genome type Ad11p and Ad11a. Virology 1992; 191:125-33. [PMID: 1413499 DOI: 10.1016/0042-6822(92)90173-m] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The early 3 region (E3) of two strains (genome type Ad11p and Ad11a) of human adenovirus serotype 11, causing persistent urinary and acute respiratory illnesses, respectively, has been identified and partially sequenced. The sequenced E3 regions of Ad11p and Ad11a were 1980 and 1966 bp long and encoded three complete ORFs, 18.5, 20.3, 20.6k within the Ad11p genome and 18.5, 20.3, 20.2k within the Ad11a genome. The sequence analysis of the 18.5k gene product demonstrated that a transmembrane domain and a cytoplasmic domain of Ad11p, Ad11a, and Ad35 was identical. Ad11p and Ad35 were homologous in the signal sequence. There was one amino acid mismatch between Ad11p and Ad11a, represented by an alanine instead of a proline. The endoplasmic reticulum lumenal domain, which binds to class I MHC, was relatively conserved between Ad11p and Ad11a with the exception of Glu80 and Glu104 in Ad11p, which were replaced by Gln80 and Lys104 in Ad11a. Within the 20.2k protein of Ad11a, the amino acid sequence Thr-Thr-Ser-His was deleted from a position immediately upstream the transmembrane region of the Ad11p 20.6k protein. The 9.0k E3 open reading frame (ORF) of Ad3 was deleted in the genomes of Ad11p and Ad11a. It is noteworthy that Ad11p and Ad35 which both cause persistent infection of the urinary tract display a remarkable similarity in several ORFs of the E3 region.
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Affiliation(s)
- Y F Mei
- Department of Virology, University of Umeå, Sweden
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34
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Brady HA, Scaria A, Wold WS. Map of cis-acting sequences that determine alternative pre-mRNA processing in the E3 complex transcription unit of adenovirus. J Virol 1992; 66:5914-23. [PMID: 1388210 PMCID: PMC241468 DOI: 10.1128/jvi.66.10.5914-5923.1992] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The E3 complex transcription unit of adenovirus encodes four major mRNAs (a, c, f, and h) and two minor (d and e) mRNAs with overlapping exons, alternative splice sites, and two polyadenylation sites, termed E3A (upstream) and E3B (downstream). mRNAs a and d use the E3A polyadenylation site, and mRNAs c, e, f, and h use the E3B site. We have analyzed virus mutants with deletions throughout the E3 region in order to identify cis-acting sequences that function in E3 pre-mRNA processing. The results presented in this report as well as previous results are summarized as follows. (i) Deletions in the first (5') intron at nucleotides (nt) 372 to 768 in E3 had no effect unless they removed the consensus sequence for the nt 372 5' splice site; however, the overall pattern of E3 mRNAs did not change significantly. (ii) Deletions in region I (nt 1441 to 2044) eliminated mRNAs a and c and resulted in corresponding increases in mRNAs f and h; we propose that region I contains sequences that suppress splicing. (iii) Mutations in region II (nt 2161 to 2243) resulted in nearly exclusive synthesis of mRNA f; this phenotype is understood and is discussed. (iv) Changing the AUUAAA component of the E3A poly(A) addition signal to AAUAAA resulted in increased mRNA a levels, suggesting that the E3A poly(A) addition signal is intrinsically inefficient. (v) Deletions in region III (nt 2488 to 3002) decreased mRNA a levels about two- to threefold and specifically increased mRNA f levels; we suggest that region III facilitates use of the E3A polyadenylation site. (vi) Deletions in region IV (nt 2904 to 3251) increased mRNA a levels about two- to threefold; we suggest that region IV may contain sequences that facilitate use of the E3B polyadenylation site. A map of sequences that determine alternative pre-mRNA processing in region E3 is now nearly complete.
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Affiliation(s)
- H A Brady
- Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110
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35
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Abstract
There is an open reading frame between ATG291 and TGA612 in the early region E3 transcription unit of adenovirus 2 (Ad2) that could encode a protein of 12,500 MW (12.5K). To address whether this protein is synthesized, we generated an antiserum against a TrpE-12.5K fusion protein which was expressed in Escherichia coli. This antiserum immunoprecipitated a doublet of about 12.5K apparent MW from [35S]Cys-labeled cells infected with Ad2, Ad5, and various mutants in other E3 genes. Mutants in the 12.5K gene did not produce this protein, and an in-frame deletion mutant showed a protein with a corresponding decrease in size. Cell-free translation of hybridization-purified RNA indicated that 12.5K is coded by E3 mRNA i. mRNA i is relatively scarce, and 12.5K is synthesized in correspondingly small amounts. The 12.5K protein was synthesized at early and late stages of infection in comparable amounts. Pulse-chase experiments indicated that 12.5K has a half-life of about 10 hr. The function of 12.5K is unknown, and the 12.5K gene can be deleted without affecting virus growth in cell culture. However, 12.5K is likely to be important in vivo because the gene is highly conserved in both Ad2 and Ad5 (group C adenoviruses), and also in Ad3 (group B).
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Affiliation(s)
- L K Hawkins
- Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110
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36
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Krajcsi P, Tollefson AE, Wold WS. The E3-14.5K integral membrane protein of adenovirus that is required for down-regulation of the EGF receptor and for prevention of TNF cytolysis is O-glycosylated but not N-glycosylated. Virology 1992; 188:570-9. [PMID: 1533979 DOI: 10.1016/0042-6822(92)90511-m] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The adenovirus E3-14.5K protein is a cytoplasmic integral membrane protein that functions in concert with the E3-10.4K protein to down-regulate the epidermal growth factor receptor and to prevent tumor necrosis factor cytolysis in adenovirus-infected cells. The 14.5K protein migrates as multiple bands in SDS-PAGE, indicating that it undergoes post-translational modification. The 14.5K protein is known to be phosphorylated on serine. We show here that 14.5K can be metabolically labeled with [3H]glucosamine, that the label is labile to alkali, and that the SDS-PAGE band pattern is simplified in a cell line that is defective in O-glycosylation. Thus, 14.5K is O-glycosylated, probably at a single site in the NH2-terminal lumenal domain. The protein was not metabolically labeled with [3H]mannose, and its SDS-PAGE band pattern was not affected by tunicamycin treatment in vivo or endo F treatment in vitro; thus, 14.5K is not N-glycosylated. There was no evidence that the 10.4K protein is glycosylated, and the 10.4K protein was not required for glycosylation of 14.5K. Virtually all 14.5K molecules appear to contain the core disaccharide Gal beta 1-3GalNAc alpha 1-Ser/Thr which is commonly found on mucin-type O-glycoproteins, and neuraminidase digestion experiments indicated that this disaccharide contains terminal sialic acid.
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Affiliation(s)
- P Krajcsi
- Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110
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37
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Krajcsi P, Wold WS. The adenovirus E3-14.5K protein which is required for prevention of TNF cytolysis and for down-regulation of the EGF receptor contains phosphoserine. Virology 1992; 187:492-8. [PMID: 1532104 DOI: 10.1016/0042-6822(92)90451-t] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The E3-14.5K and E3-10.4K proteins form a complex and function to down-regulate the epidermal growth factor receptor and to prevent tumor necrosis factor cytolysis in adenovirus-infected cells. Both 14.5K and 10.4K are cytoplasmic membrane proteins with a Ccyt orientation in the membrane. We show here that 14.5K is phosphorylated on serine residues in cells infected by adenoviruses that synthesize both 14.5K and 10.4K. 14.5K is phosphorylated on both serine and threonine in cells infected by a mutant that does not synthesize 10.4K; thus, the presence or absence of 10.4K affects the phosphorylation of 14.5K. Phosphotyrosine was not detected. 14.5K is also phosphorylated when translated in vitro in a rabbit reticulocyte extract. Both in vivo and in vitro, at least one of the phosphorylation sites is near the C-terminus, in the cytoplasmic domain of 14.5K. This C-terminal region of 14.5K is the most conserved among Ad5, Ad2, Ad3, and Ad7, and it is essential for 14.5K to prevent tumor necrosis factor cytolysis.
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Affiliation(s)
- P Krajcsi
- Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110
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38
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Krajcsi P, Tollefson AE, Anderson CW, Wold WS. The adenovirus E3 14.5-kilodalton protein, which is required for down-regulation of the epidermal growth factor receptor and prevention of tumor necrosis factor cytolysis, is an integral membrane protein oriented with its C terminus in the cytoplasm. J Virol 1992; 66:1665-73. [PMID: 1531370 PMCID: PMC240906 DOI: 10.1128/jvi.66.3.1665-1673.1992] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We previously reported that the adenovirus type 5 E3 14.5-kilodalton protein (14.5K) forms a complex with E3 10.4K and that both proteins are required to down-regulate the epidermal growth factor receptor in adenovirus-infected human cells. Both proteins are also required to prevent cytolysis by tumor necrosis factor of most mouse cell lines infected by adenovirus mutants that lack E3 14.7K. The E3 14.5K amino acid sequence suggests that 14.5K is an integral membrane protein with an N-terminal signal sequence for membrane insertion. Here we show that 14.5K was found exclusively in cytoplasmic membrane fractions. Radiochemical sequencing of 14.5K indicated that the N-terminal signal sequence is cleaved predominantly between Cys-18 and Ser-19. With a mutant that does not express 10.4K, cleavage occurs predominantly between Phe-17 and Cys-18, indicating that the presence or absence of 10.4K affects the signal cleavage site. 14.5K was extracted into the detergent phase with Triton X-114, it remained associated with membranes after extraction with Na2CO3 at pH 11.5, and it was partially protected by membranes from proteinase K digestion; these observations indicate that 14.5K is an integral membrane protein. Proteinase K digestion followed by immunoprecipitation with antipeptide antisera directed against the N or C terminus of mature 14.5K indicated that 14.5K is oriented in the membrane with its N terminus in the lumen and its C terminus in the cytoplasm. Thus, 14.5K is a type I bitopic membrane protein. Previous studies indicated that 10.4K is also an integral membrane protein oriented with its C terminus in the cytoplasm. Altogether, these findings suggest that cytoplasmic membranes are the site of action when 10.4K and 14.5K down-regulate the epidermal growth factor receptor and prevent tumor necrosis factor cytolysis.
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Affiliation(s)
- P Krajcsi
- Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110
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39
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Krajcsi P, Tollefson AE, Anderson CW, Stewart AR, Carlin CR, Wold WS. The E3-10.4K protein of adenovirus is an integral membrane protein that is partially cleaved between Ala22 and Ala23 and has a Ccyt orientation. Virology 1992; 187:131-44. [PMID: 1531278 DOI: 10.1016/0042-6822(92)90302-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Ad2 E3-10.4K protein is required together with the E3-14.5K protein to down-regulate the epidermal growth factor receptor in adenovirus-infected cells. Both proteins are also required to prevent tumor necrosis factor cytolysis under certain conditions. 10.4K is a 91 amino acid membrane-associated protein that migrates as two bands, upper and lower, on SDS-PAGE. We show here that the upper band is the primary translation product which initiates at AUG2173 in the E3 transcription unit of Ad2. The upper band is processed slowly (greater than 4 hr to complete) into the lower band by proteolytic cleavage between residues Ala22 and Ala23 by a microsome-associated protease. The upper and lower bands become equal in abundance, after which they are very stable. The N-terminus of the in vivo-derived upper band is not blocked to sequencing and it retains its initiating Met. 10.4K has a hydrophobic domain (H1) near its N-terminus that is probably a signal sequence for membrane insertion; cleavage of this signal is atypical because it was not cotranslational in vivo and it was not complete. 10.4K has a second hydrophobic domain (H2) located within residues 35-60. H2 appears to be a transmembrane (stop transfer) domain because both the upper and the lower 10.4K bands remained associated with membranes after extraction at pH 11.5, because both bands were extracted into the detergent phase with Triton X-114, and because both bands were only partially reduced in size when 10.4K-containing microsomes were digested with proteinase K. These proteinase K-digested bands were immunoprecipitated with an antipeptide antiserum against residues 19-34 but not with an antiserum against residues 68-80 or 77-91, indicating that both 10.4K bands are orientated in the membrane with the C-terminus in the cytoplasm. We conclude that the lower band of 10.4K is a type I bitopic membrane protein and suggest that the upper band is a polytopic membrane protein with both the H1 and the H2 hydrophobic domains spanning the membrane.
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MESH Headings
- Adenovirus Early Proteins
- Adenoviruses, Human/chemistry
- Adenoviruses, Human/genetics
- Adenoviruses, Human/metabolism
- Amino Acid Sequence
- Antigens, Viral, Tumor/chemistry
- Antigens, Viral, Tumor/genetics
- Antigens, Viral, Tumor/metabolism
- Cell Line
- Endopeptidase K
- Humans
- Microsomes/metabolism
- Molecular Sequence Data
- Oncogene Proteins, Viral/chemistry
- Oncogene Proteins, Viral/genetics
- Oncogene Proteins, Viral/metabolism
- Precipitin Tests
- Serine Endopeptidases/metabolism
- Viral Envelope Proteins/chemistry
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/metabolism
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Affiliation(s)
- P Krajcsi
- Institute for Molecualr Virology, St. Louis University School of Medicine, Missouri 63110
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40
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Abstract
Five structural features in mRNAs have been found to contribute to the fidelity and efficiency of initiation by eukaryotic ribosomes. Scrutiny of vertebrate cDNA sequences in light of these criteria reveals a set of transcripts--encoding oncoproteins, growth factors, transcription factors, and other regulatory proteins--that seem designed to be translated poorly. Thus, throttling at the level of translation may be a critical component of gene regulation in vertebrates. An alternative interpretation is that some (perhaps many) cDNAs with encumbered 5' noncoding sequences represent mRNA precursors, which would imply extensive regulation at a posttranscriptional step that precedes translation.
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Affiliation(s)
- M Kozak
- Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Piscataway 08854
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41
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Wold WS, Gooding LR. Region E3 of adenovirus: a cassette of genes involved in host immunosurveillance and virus-cell interactions. Virology 1991; 184:1-8. [PMID: 1831308 DOI: 10.1016/0042-6822(91)90815-s] [Citation(s) in RCA: 196] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- W S Wold
- Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110
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42
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Gooding LR, Ranheim TS, Tollefson AE, Aquino L, Duerksen-Hughes P, Horton TM, Wold WS. The 10,400- and 14,500-dalton proteins encoded by region E3 of adenovirus function together to protect many but not all mouse cell lines against lysis by tumor necrosis factor. J Virol 1991; 65:4114-23. [PMID: 1830111 PMCID: PMC248844 DOI: 10.1128/jvi.65.8.4114-4123.1991] [Citation(s) in RCA: 121] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We have reported that the E3 14,700-dalton protein (E3 14.7K protein) protects adenovirus-infected mouse C3HA fibroblasts against lysis by tumor necrosis factor (TNF) (L. R. Gooding, L. W. Elmore, A. E. Tollefson, H. A. Brady, and W. S. M. Wold, Cell 53:341-346, 1988). We have also observed that the E1B 19K protein protects adenovirus-infected human but not mouse cells against TNF lysis (L. R. Gooding, L. Aquino, P. J. Duerksen-Hughes, D. Day, T. M. Horton, S. Yei, and W. S. M. Wold, J. Virol. 65:3083-3094, 1991). We now report that, in the absence of E3 14.7K, the E3 10.4K and E3 14.5K proteins are both required to protect C127 as well as several other mouse cell lines against TNF lysis. The 14.7K protein can also protect these cells from TNF in the absence of the 10.4K and 14.5K proteins. This protection by the 10.4K and 14.5K proteins was not observed in the C3HA cell line. These conclusions are based on 51Cr release assays of cells infected with virus E3 mutants that express the 14.7K protein alone, that express both the 10.4K and 14.5K proteins, and that delete the 14.7K in combination with either the 10.4K or 14.5K protein. The 10.4K protein was efficiently coimmunoprecipitated together with the 14.5K protein by using an antiserum to the 14.5K protein, suggesting that the 10.4K and 14.5K proteins exist as a complex in the infected mouse cells and consistent with the notion that they function in concert. Considering that three sets of proteins (E3 14.7K, E1B 19K, and E3 10.4K/14.5K proteins) exist in adenovirus to prevent TNF cytolysis of different cell types, it would appear that TNF is a major antiadenovirus defense of the host.
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Affiliation(s)
- L R Gooding
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322
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43
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Tollefson AE, Stewart AR, Yei SP, Saha SK, Wold WS. The 10,400- and 14,500-dalton proteins encoded by region E3 of adenovirus form a complex and function together to down-regulate the epidermal growth factor receptor. J Virol 1991; 65:3095-105. [PMID: 1851870 PMCID: PMC240965 DOI: 10.1128/jvi.65.6.3095-3105.1991] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In adenovirus-infected cells, the epidermal growth factor receptor (EGF-R) is internalized from the cell surface via endosomes and is degraded, and the E3 10,400-dalton protein (10.4K protein) is required for this effect (C. R. Carlin, A. E. Tollefson, H. A. Brady, B. L. Hoffman, and W. S. M. Wold, Cell 57:135-144, 1989). We now report that both the E3 10.4K and E3 14.5K proteins are required for this down-regulation of EGF-R in adenovirus-infected cells. Down-regulation of cell surface EGF-R was demonstrated by results from several methods, namely the absence of EGF-R autophosphorylation in an immune complex kinase assay, the inability to iodinate EGF-R on the cell surface, the formation of endosomes containing EGF-R as detected by immunofluorescence, and the degradation of the metabolically [35S]Met-labeled fully processed 170K species of EGF-R. No effect on the initial synthesis of EGF-R was observed. This down-regulation was ascribed to the 10.4K and 14.5K proteins through the analysis of cells infected with rec700 (wild-type), dl748 (10.4K-, 14.5K+), or dl764 (10.4K+, 14.5K-) or coinfected with dl748 plus dl764. Further evidence that the 10.4K and 14.5K proteins function in concert was obtained by demonstrating that the 10.4K protein was coimmunoprecipitated with the 14.5K protein by using three different antisera to the 14.5K protein, strongly implying that the 10.4K and 14.5K proteins exist as a complex. Together, these results indicate that the 10.4K and 14.5K proteins function as a complex to stimulate endosome-mediated internalization and degradation of EGF-R in adenovirus-infected cells.
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Affiliation(s)
- A E Tollefson
- Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110
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44
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Gooding LR, Aquino L, Duerksen-Hughes PJ, Day D, Horton TM, Yei SP, Wold WS. The E1B 19,000-molecular-weight protein of group C adenoviruses prevents tumor necrosis factor cytolysis of human cells but not of mouse cells. J Virol 1991; 65:3083-94. [PMID: 1827845 PMCID: PMC240964 DOI: 10.1128/jvi.65.6.3083-3094.1991] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Tumor necrosis factor (TNF) is a multifunctional immunoregulatory protein that is secreted by activated macrophages and is believed to have antiviral activities. We reported earlier that when mouse C3HA fibroblasts are infected with human adenoviruses, the 289R and 243R proteins encoded by region E1A render the cells susceptible to lysis by TNF, and a 14,700-molecular-weight protein (14.7K protein) encoded by region E3 protects the cells against lysis by TNF. We now report that the 19,000-molecular-weight (19K) (176R) protein encoded by the E1B transcription unit can protect human HEL-299 fibroblasts and human ME-180 cervical carcinoma cells against lysis by TNF. This was determined by infecting cells with adenovirus double mutants that lack region E3 and do or do not express the E1B-19K protein and by measuring cytolysis by using a short-term (18-h) 51Cr-release assay. Under these assay conditions, the 51Cr release was specific to TNF and was not a consequence of the cyt phenotype associated with E1B-19K protein-negative mutants. Also, by using virus double mutants that lack E3 in combination with other early regions, we found that E1A, the E1B-55K protein-encoding gene, E3, and E4 are not required to protect HEL-299 cells against TNF cytolysis. Three additional human cancer cell lines (HeLa, HCT8, and RC29) and a simian virus 40-transformed WI38 cell line (VA-13) also required E1B for protection against TNF cytolysis, indicating that the E1B-19K protein is required to protect many if not all human cell types against lysis by TNF when infected by adenovirus. The E1B-19K protein was not able to protect six different adenovirus-infected mouse cell lines against TNF lysis, even though the protein was shown to be efficiently expressed in one of the cell lines. HEL-299 or ME-180 cells infected by a mutant that lacks the E1B-19K protein but retains region E3 were not lysed by TNF, indicating that one or more of the E3 proteins can protect these cells against TNF lysis in the absence of the E1B-19K protein. Thus, the E3-14.7K but not the E1B-19K protein can protect adenovirus-infected mouse cells against TNF cytolysis, whereas the E1B-19K protein as well as one or more of the E3 proteins can protect adenovirus-infected human cells against TNF cytolysis.
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Affiliation(s)
- L R Gooding
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322
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45
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Wilson-Rawls J, Saha SK, Krajcsi P, Tollefson AE, Gooding LR, Wold WS. A 6700 MW membrane protein is encoded by region E3 of adenovirus type 2. Virology 1990; 178:204-12. [PMID: 1697127 DOI: 10.1016/0042-6822(90)90395-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
There is an open reading frame between ATG1022 and TGA1205 in the E3 transcription unit of adenovirus 2 that could encode a protein of MW 6700 (6.7K) (61 amino acids). To address whether this protein is expressed, we prepared an antiserum against a synthetic peptide corresponding to residues 47-61 in the 6.7K protein. This antiserum immunoprecipitated two series of protein bands, a 7K-8K doublet and a 15K-16K doublet or triplet, as observed by electrophoresis on 10-18% gradient SDS-polyacrylamide gels. These bands were not obtained from cells infected with mutants that lack the 6.7K gene. Most, if not all, of the 7K-8K and 15K-16K bands were detected by immunoblot, indicating that they are modified versions of the 6.7K protein. Only an 8K band was observed after cell-free translation of hybridization-purified mRNA, suggesting that this may be the primary translation product. As judged by DNA sequence, the 6.7K protein has a hydrophobic domain of at least 22 residues (residues 16-37), suggesting that 6.7K may be a membrane protein. Consistent with this, the 7K-8K and 15K-16K bands were observed in the crude membrane but not the cytosol or nuclear fractions of biochemically fractionated cells. The 6.7K protein was underproduced by mutants which underproduce E3 mRNAs a and c, indicating that 6.7K is translated from these mRNAs. Since the E3-gp 19K protein is also translated from mRNAs a and c, these mRNAs are bicistronic. The 6.7K protein is well-conserved in Ad5 (Ad2 and Ad5 are group C adenoviruses), and appears to be marginally conserved in Ad3 (group B).
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Affiliation(s)
- J Wilson-Rawls
- Institute for Molecular Virology, St. Louis University Medical Center, Missouri 63110
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