Reichel, A.* ; Stilp, A.C.* ; Scherer, M.* ; Reuter, N.* ; Lukassen, S.* ; Kasmapour, B.* ; Schreiner, S. ; Cicin-Sain, L.* ; Winterpacht, A.* ; Stamminger, T.*
Chromatin-remodeling factor SPOC1 acts as a cellular restriction factor against human cytomegalovirus by repressing the major immediate early promoter.
J. Virol. 92:e00342-18 (2018)
The cellular protein SPOC1 (survival time-associated PHD [plant homeodomain] finger protein in ovarian cancer 1) acts as a regulator of chromatin structure and the DNA damage response. It binds H3K4me2/3-containing chromatin and promotes DNA condensation by recruiting corepressors such as KAP-1 and H3K9 methyltransferases. Previous studies identified SPOC1 as a restriction factor against human adenovirus (HAdV) infection that is antagonized by E1B-55K/E4-orf6-dependent proteasomal degradation. Here, we demonstrate that, in contrast to HAdV-infected cells, SPOC1 is transiently upregulated during the early phase of human cytomegalovirus (HCMV) replication. We show that the expression of immediate early protein 1 (IE1) is sufficient and necessary to induce SPOC1. Additionally, we discovered that during later stages of infection, SPOC1 is downregulated in a glycogen synthase kinase 3 beta (GSK-3 beta)-dependent manner. We provide evidence that SPOC1 overexpression severely impairs HCMV replication by repressing the initiation of viral immediate early (IE) gene expression. Consistently, we observed that SPOC1-depleted primary human fibroblasts displayed an augmented initiation of viral IE gene expression. This occurs in a multiplicity of infection (MOI)-dependent manner, a defining hallmark of intrinsic immunity. Interestingly, repression requires the presence of high SPOC1 levels at the start of infection, while later upregulation had no negative impact, suggesting distinct temporal roles of SPOC1 during the HCMV replicative cycle. Mechanistically, we observed a highly specific association of SPOC1 with the major immediate early promoter (MIEP), strongly suggesting that SPOC1 inhibits HCMV replication by MIEP binding and the subsequent recruitment of heterochromatin-building factors. Thus, our data add SPOC1 as a novel factor to the endowment of a host cell to restrict cytomegalovirus infections.IMPORTANCE Accumulating evidence indicates that during millennia of coevolution, host cells have developed a sophisticated compilation of cellular factors to restrict cytomegalovirus infections. Defining this equipment is important to understand cellular barriers against viral infection and to develop strategies to utilize these factors for antiviral approaches. So far, constituents of PML nuclear bodies and interferon gamma-inducible protein 16 (IFI16) were known to mediate intrinsic immunity against HCMV. In this study, we identify the chromatin modulator SPOC1 as a novel restriction factor against HCMV. We show that preexisting high SPOC1 protein levels mediate a silencing of HCMV gene expression via a specific association with an important viral cis-regulatory element, the major immediate early promoter. Since SPOC1 expression varies between cell types, this factor may play an important role in tissue-specific defense against HCMV.
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Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
Human Cytomegalovirus ; Immediate Early ; Intrinsic Immunity ; Restriction Factor; Viral Gene-expression; Homology-directed Repair; Dna-damage Response; Open Reading Frame; Nuclear Domain 10; Covalent Modification; Permissive Cells; Protein; Infection; Pml
Keywords plus
Sprache
Veröffentlichungsjahr
2018
Prepublished im Jahr
HGF-Berichtsjahr
2018
ISSN (print) / ISBN
0022-538X
e-ISSN
1098-5514
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 92,
Heft: 14,
Seiten: ,
Artikelnummer: e00342-18
Supplement: ,
Reihe
Verlag
American Society for Microbiology (ASM)
Verlagsort
1752 N St Nw, Washington, Dc 20036-2904 Usa
Tag d. mündl. Prüfung
0000-00-00
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Prüfer
Topic
Hochschule
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Veröffentlichungsdatum
0000-00-00
Anmeldedatum
0000-00-00
Anmelder/Inhaber
weitere Inhaber
Anmeldeland
Priorität
Begutachtungsstatus
Peer reviewed
POF Topic(s)
30203 - Molecular Targets and Therapies
Forschungsfeld(er)
Immune Response and Infection
PSP-Element(e)
G-502700-007
Förderungen
Copyright
Erfassungsdatum
2018-06-26