scholarly journals Association of Mumps Virus V Protein with RACK1 Results in Dissociation of STAT-1 from the Alpha Interferon Receptor Complex

2002 ◽  
Vol 76 (24) ◽  
pp. 12676-12682 ◽  
Author(s):  
Toru Kubota ◽  
Noriko Yokosawa ◽  
Shin-ichi Yokota ◽  
Nobuhiro Fujii
Keyword(s):  
Signal Transduction Pathway ◽  
Adaptor Protein ◽  
Mumps Virus ◽  
Virus Protein ◽  
V Protein ◽  
Long Form ◽  
Infected Cells ◽  
Intracellular Target ◽  
Two Hybrid ◽  
Hybrid Screening

ABSTRACT It has been reported that mumps virus protein V or the C-terminal Cys-rich region of protein V (Vsp) is associated with blocking of the interferon (IFN) signal transduction pathway through a decrease in STAT-1 production. The intracellular target of the V protein was investigated by using a two-hybrid screening system with Vsp as bait. Full-length V protein and Vsp were able to bind to RACK1, and the interaction did not require two WD domains, WD1 and WD2, in RACK1. A significant interaction between V protein and RACK1 was also demonstrated in cells persistently infected with mumps virus (FLMT cells), and the formation of the complex was not affected by treatment with IFN. On the other hand, in uninfected cells, STAT-1 was associated with the long form of the β subunit of the alpha IFN receptor, and this association was mediated by the function of RACK1 as an adaptor protein. Immunoprecipitation and glutathione S-transferase pull-down experiments revealed that the association of RACK1 or mumps virus V protein with the IFN receptor was undetectable in mumps virus-infected cells. Furthermore, RACK1 interacted with mumps virus V protein with a higher affinity than STAT-1 did. Therefore, it is suggested that mumps virus V protein has the ability to interact strongly with RACK1 and consequently to bring about the disruption of the complex formed from STAT-1, RACK1, and the IFN receptor.

The mumps virus V protein is unstable in virus infected cells

1993 ◽  
Vol 133 (1-2) ◽  
pp. 201-209 ◽  
Author(s):  
A. Hu ◽  
S. Schwartz ◽  
G. Utter ◽  
C. �rvell ◽  
J. K�vamees ◽  
...  
Keyword(s):  
Mumps Virus ◽  
V Protein ◽  
Infected Cells

scholarly journals Mumps Virus V Protein Antagonizes Interferon without the Complete Degradation of STAT1

2005 ◽  
Vol 79 (7) ◽  
pp. 4451-4459 ◽  
Author(s):  
Toru Kubota ◽  
Noriko Yokosawa ◽  
Shin-ichi Yokota ◽  
Nobuhiro Fujii ◽  
Masato Tashiro ◽  
...  
Keyword(s):  
Protein Function ◽  
Nuclear Translocation ◽  
Cysteine Residue ◽  
Mumps Virus ◽  
Unique Region ◽  
V Protein ◽  
Complete Degradation ◽  
Infected Cells ◽  
Induced Signal ◽  
Viral Components

ABSTRACT Mumps virus (MuV) has been shown to antagonize the antiviral effects of interferon (IFN) through proteasome-mediated complete degradation of STAT1 by using the viral V protein (T. Kubota et al., Biochem. Biophys. Res. Commun. 283:255-259, 2001). However, we found that MuV could inhibit IFN signaling and the generation of a subsequent antiviral state long before the complete degradation of cellular STAT1 in infected cells. In MuV-infected cells, nuclear translocation and phosphorylation of STAT1 and STAT2 tyrosine residue (Y) at 701 and 689, respectively, by IFN-β were significantly inhibited but the phosphorylation of Jak1 and Tyk2 was not inhibited. The transiently expressed MuV V protein also inhibited IFN-β-induced Y701-STAT1 and Y689-STAT2 phosphorylation, suggesting that the V protein could block IFN-β-induced signal transduction without the aid of other viral components. Finally, a substitution of an alanine residue in place of a cysteine residue in the C-terminal V-unique region known to be required for STAT1 degradation and inhibition of anti-IFN signaling resulted in the loss of V protein function to inhibit the Y701-STAT1 and Y689-STAT2 phosphorylation.

scholarly journals Human cytomegalovirus interactome analysis identifies degradation hubs, domain associations and viral protein functions

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Luis V Nobre ◽  
Katie Nightingale ◽  
Benjamin J Ravenhill ◽  
Robin Antrobus ◽  
Lior Soday ◽  
...  
Keyword(s):  
Viral Replication ◽  
Human Cytomegalovirus ◽  
Protein Interactions ◽  
Adaptor Protein ◽  
Host Cells ◽  
Virus Protein ◽  
Protein Functions ◽  
Mechanism Of Degradation ◽  
Human Proteins ◽  
Infected Cells

Human cytomegalovirus (HCMV) extensively modulates host cells, downregulating >900 human proteins during viral replication and degrading ≥133 proteins shortly after infection. The mechanism of degradation of most host proteins remains unresolved, and the functions of many viral proteins are incompletely characterised. We performed a mass spectrometry-based interactome analysis of 169 tagged, stably-expressed canonical strain Merlin HCMV proteins, and two non-canonical HCMV proteins, in infected cells. This identified a network of >3400 virus-host and >150 virus-virus protein interactions, providing insights into functions for multiple viral genes. Domain analysis predicted binding of the viral UL25 protein to SH3 domains of NCK Adaptor Protein-1. Viral interacting proteins were identified for 31/133 degraded host targets. Finally, the uncharacterised, non-canonical ORFL147C protein was found to interact with elements of the mRNA splicing machinery, and a mutational study suggested its importance in viral replication. The interactome data will be important for future studies of herpesvirus infection.

scholarly journals The Cellular RNA Helicase DDX1 Interacts with Coronavirus Nonstructural Protein 14 and Enhances Viral Replication

2010 ◽  
Vol 84 (17) ◽  
pp. 8571-8583 ◽  
Author(s):  
Linghui Xu ◽  
Siti Khadijah ◽  
Shouguo Fang ◽  
Li Wang ◽  
Felicia P. L. Tay ◽  
...  
Keyword(s):  
Nonstructural Protein ◽  
Rna Helicase ◽  
Host Proteins ◽  
Bait Protein ◽  
Infectious Bronchitis ◽  
Infected Cells ◽  
Interfering Rna ◽  
Discontinuous Transcription ◽  
Two Hybrid ◽  
Hybrid Screening

ABSTRACT The involvement of host proteins in the replication and transcription of viral RNA is a poorly understood area for many RNA viruses. For coronaviruses, it was long speculated that replication of the giant RNA genome and transcription of multiple subgenomic mRNA species by a unique discontinuous transcription mechanism may require host cofactors. To search for such cellular proteins, yeast two-hybrid screening was carried out by using the nonstructural protein 14 (nsp14) from the coronavirus infectious bronchitis virus (IBV) as a bait protein, leading to the identification of DDX1, a cellular RNA helicase in the DExD/H helicase family, as a potential interacting partner. This interaction was subsequently confirmed by coimmunoprecipitation assays with cells coexpressing the two proteins and with IBV-infected cells. Furthermore, the endogenous DDX1 protein was found to be relocated from the nucleus to the cytoplasm in IBV-infected cells. In addition to its interaction with IBV nsp14, DDX1 could also interact with the nsp14 protein from severe acute respiratory syndrome coronavirus (SARS-CoV), suggesting that interaction with DDX1 may be a general feature of coronavirus nsp14. The interacting domains were mapped to the C-terminal region of DDX1 containing motifs V and VI and to the N-terminal portion of nsp14. Manipulation of DDX1 expression, either by small interfering RNA-induced knockdown or by overexpression of a mutant DDX1 protein, confirmed that this interaction may enhance IBV replication. This study reveals that DDX1 contributes to efficient coronavirus replication in cell culture.

scholarly journals STAT3 Ubiquitylation and Degradation by Mumps Virus Suppress Cytokine and Oncogene Signaling

2003 ◽  
Vol 77 (11) ◽  
pp. 6385-6393 ◽  
Author(s):  
Christina M. Ulane ◽  
Jason J. Rodriguez ◽  
Jean-Patrick Parisien ◽  
Curt M. Horvath
Keyword(s):  
Tyrosine Kinases ◽  
Protein A ◽  
Infectious Agent ◽  
Mumps Virus ◽  
Virus Protein ◽  
Transcriptional Responses ◽  
V Protein ◽  
Antiviral Responses ◽  
Cellular Components ◽  
Nonreceptor Tyrosine Kinases

ABSTRACT Mumps virus is a common infectious agent of humans, causing parotitis, meningitis, encephalitis, and orchitis. Like other paramyxoviruses in the genus Rubulavirus, mumps virus catalyzes the proteasomal degradation of cellular STAT1 protein, a means for escaping antiviral responses initiated by alpha/beta and gamma interferons. We demonstrate that mumps virus also eliminates cellular STAT3, a protein that mediates transcriptional responses to cytokines, growth factors, nonreceptor tyrosine kinases, and a variety of oncogenic stimuli. STAT1 and STAT3 are independently targeted by a single mumps virus protein, called V, that assembles STAT-directed ubiquitylation complexes from cellular components, including STAT1, STAT2, STAT3, DDB1, and Cullin4A. Consequently, mumps virus V protein prevents responses to interleukin-6 and v-Src signals and can induce apoptosis in STAT3-dependent multiple myeloma cells and transformed murine fibroblasts. These findings demonstrate a unique cytokine and oncogene evasion property of mumps virus that provides a molecular basis for its observed oncolytic properties.

scholarly journals Interactions of Rotavirus VP4 Spike Protein with the Endosomal Protein Rab5 and the Prenylated Rab Acceptor PRA1

2003 ◽  
Vol 77 (12) ◽  
pp. 7041-7047 ◽  
Author(s):  
Vincent Enouf ◽  
Serge Chwetzoff ◽  
Germain Trugnan ◽  
Jean Cohen
Keyword(s):  
Amino Acids ◽  
Cell Attachment ◽  
Small Gtpase ◽  
Spike Protein ◽  
Deletion Mutants ◽  
Vesicular Traffic ◽  
Early Endosomes ◽  
Infected Cells ◽  
Two Hybrid ◽  
Hybrid Screening

ABSTRACT Rotavirus spike protein VP4 is implicated in several important functions, such as cell attachment, penetration, hemagglutination, neutralization, virulence, and host range. It is present at the plasma membrane and colocalizes with the cytoskeleton in infected cells. We looked for cellular partners responsible for the localization of VP4 by two-hybrid screening of a monkey CV1 cell cDNA library. In the screen we isolated repeatedly three cDNAs encoding either two isoforms (a and c) of Rab5 protein or the prenylated Rab acceptor (PRA1). The small GTPase Rab5 is a molecule regulating the vesicular traffic and the motility of early endosomes along microtubules. Rab5 interacts with a large number of effectors, in particular with PRA1. Interactions of VP4 with both partners, Rab5 and PRA1, were confirmed by coimmunoprecipitation from infected- or transfected-cell lysates. Interaction of Rab5 and PRA1 was restricted to free VP4, since neither triple-layered particles nor NSP4-VP4-VP7 heterotrimeric complexes could be coprecipitated. Site-directed and deletion mutants of VP4 were used to map a VP4 domain(s) interacting with Rab5 or PRA1. Of the 10 mutants tested, 2 interacted exclusively with a single partner. In contrast, the domain extending from amino acids 560 to 722 of VP4 is essential for both interactions. These results suggest that Rab5 and PRA1 may be involved in the localization and trafficking of VP4 in infected cells.

scholarly journals Two LIM Domain Proteins and UNC-96 Link UNC-97/PINCH to Myosin Thick Filaments in Caenorhabditis elegans Muscle

2007 ◽  
Vol 18 (11) ◽  
pp. 4317-4326 ◽  
Author(s):  
Hiroshi Qadota ◽  
Kristina B. Mercer ◽  
Rachel K. Miller ◽  
Kozo Kaibuchi ◽  
Guy M. Benian
Keyword(s):  
Caenorhabditis Elegans ◽  
Binding Assays ◽  
Lim Domain ◽  
Yeast Two Hybrid ◽  
Lim Domains ◽  
Thick Filaments ◽  
Vitro Binding ◽  
Two Hybrid ◽  
Hybrid Screening

By yeast two-hybrid screening, we found three novel interactors (UNC-95, LIM-8, and LIM-9) for UNC-97/PINCH in Caenorhabditis elegans. All three proteins contain LIM domains that are required for binding. Among the three interactors, LIM-8 and LIM-9 also bind to UNC-96, a component of sarcomeric M-lines. UNC-96 and LIM-8 also bind to the C-terminal portion of a myosin heavy chain (MHC), MHC A, which resides in the middle of thick filaments in the proximity of M-lines. All interactions identified by yeast two-hybrid assays were confirmed by in vitro binding assays using purified proteins. All three novel UNC-97 interactors are expressed in body wall muscle and by antibodies localize to M-lines. Either a decreased or an increased dosage of UNC-96 results in disorganization of thick filaments. Our previous studies showed that UNC-98, a C2H2 Zn finger protein, acts as a linkage between UNC-97, an integrin-associated protein, and MHC A in myosin thick filaments. In this study, we demonstrate another mechanism by which this linkage occurs: from UNC-97 through LIM-8 or LIM-9/UNC-96 to myosin.

scholarly journals A Novel Human Ada2 Homologue Functions with Gcn5 or Brg1 To Coactivate Transcription

2003 ◽  
Vol 23 (19) ◽  
pp. 6944-6957 ◽  
Author(s):  
Nickolai A. Barlev ◽  
Alexander V. Emelyanov ◽  
Paola Castagnino ◽  
Philip Zegerman ◽  
Andrew J. Bannister ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
Chromatin Remodeling ◽  
Adaptor Protein ◽  
Saga Complex ◽  
Yeast Two Hybrid ◽  
Functional Assays ◽  
Two Hybrid ◽  
Histone Acetyltransferase Activity

ABSTRACT In yeast, the transcriptional adaptor yeast Ada2 (yAda2) is a part of the multicomponent SAGA complex, which possesses histone acetyltransferase activity through action of the yGcn5 catalytic enzyme. yAda2, among several SAGA proteins, serves to recruit SAGA to genes via interactions with promoter-bound transcription factors. Here we report identification of a new human Ada2 homologue, hAda2β. Ada2β differs both biochemically and functionally from the previously characterized hAda2α, which is a stable component of the human PCAF (human Gcn5 homologue) acetylase complex. Ada2β, relative to Ada2α, interacted selectively, although not stably, with the Gcn5-containing histone acetylation complex TFTC/STAGA. In addition, Ada2β interacted with Baf57 (a component of the human Swi/Snf complex) in a yeast two-hybrid screen and associated with human Swi/Snf in vitro. In functional assays, hAda2β (but not Ada2α), working in concert with Gcn5 (but not PCAF) or Brg1 (the catalytic component of hSwi/Snf complex), increased transcription via the B-cell-specific transcription factor Pax5/BSAP. These findings support the view that Gcn5 and PCAF have distinct roles in vivo and suggest a new mechanism of coactivator function, in which a single adaptor protein (Ada2β) can coordinate targeting of both histone acetylation and chromatin remodeling activities.

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