Dataset Information

Binding of Avibirnavirus VP3 to the PIK3C3-PDPK1 complex inhibits autophagy by activating the AKT-MTOR pathway.

ABSTRACT: Macroautophagy/autophagy is a host natural defense response. Viruses have developed various strategies to subvert autophagy during their life cycle. Recently, we revealed that autophagy was activated by binding of Avibirnavirus to cells. In the present study, we report the inhibition of autophagy initiated by PIK3C3/VPS34 via the PDPK1-dependent AKT-MTOR pathway. Autophagy detection revealed that viral protein VP3 triggered inhibition of autophagy at the early stage of Avibirnavirus replication. Subsequent interaction analysis showed that the CC1 domain of VP3 disassociated PIK3C3-BECN1 complex by direct interaction with BECN1 and blocked autophagosome formation, while the CC3 domain of VP3 disrupted PIK3C3-PDPK1 complex via directly binding to PIK3C3 and inhibited both formation and maturation of autophagosome. Furthermore, we found that PDPK1 activated AKT-MTOR pathway for suppressing autophagy via binding to AKT. Finally, we proved that CC3 domain was critical for role of VP3 in regulating replication of Avibirnavirus through autophagy. Taken together, our study identified that Avibirnavirus VP3 links PIK3C3-PDPK1 complex to AKT-MTOR pathway and inhibits autophagy, a critical step for controlling virus replication.

Abbreviations

ATG14/Barkor: autophagy related 14; BECN1: beclin 1; CC: coiled-coil; ER: endoplasmic reticulum; hpi: hours post-infection; IBDV: infectious bursal disease virus; IP: co-immunoprecipitation; mAb: monoclonal antibody; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; PDPK1: 3-phosphoinositid-dependent protein kinase-1; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; SQSTM1: sequestosome 1; vBCL2: viral BCL2 apoptosis regulator.

SUBMITTER: Zhang Y

PROVIDER: S-EPMC8386615 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Binding of Avibirnavirus VP3 to the PIK3C3-PDPK1 complex inhibits autophagy by activating the AKT-MTOR pathway.

Zhang Yina Y Hu Boli B Li Yahui Y Deng Tingjuan T Xu Yuting Y Lei Jing J Zhou Jiyong J

Autophagy 20191229 9

Macroautophagy/autophagy is a host natural defense response. Viruses have developed various strategies to subvert autophagy during their life cycle. Recently, we revealed that autophagy was activated by binding of Avibirnavirus to cells. In the present study, we report the inhibition of autophagy initiated by PIK3C3/VPS34 via the PDPK1-dependent AKT-MTOR pathway. Autophagy detection revealed that viral protein VP3 triggered inhibition of autophagy at the early stage of Avibirnavirus</i ...[more]

PMID: 31885313

Similar Datasets

Project description:Autophagy is a lysosome-dependent degradation program to maintain cellular homeostasis in response to a variety of stressful conditions, such as long-lived or non-functional subcellular organelles, protein aggregates, nutrient limitation, and virus/bacteria infection. Accordingly, dysregulation of autophagy is closely associated with many human pathophysiological conditions, such as neurodegenerative diseases, aging, and cancer, and autophagy is highlighted as an important therapeutic target for these human diseases. In autophagy process, PIK3C3/VPS34 complex plays important roles in autophagosome biogenesis. Accumulating evidences that inhibition of PIK3C3/VPS34 complex successfully blocks autophagy make the complex as an attractive target for the development of autophagy-specific inhibitors. However, considering that various forms of PIK3C3/VPS34 complex exist and they are involved in many different cellular functions, the targeting of the pro-autophagy PIK3C3/VPS34 complex is required to specifically inhibit autophagy. To identify autophagy inhibitors targeting the pro-autophagy complex, we have performed the screening of a customized natural product library consisting of 35 herbal extracts which are widely used in the oriental medicine as anti-inflammation and/or anti-tumor reagents. We discovered that an alcoholic extract of Thuja orientalis L. leaves inhibits pro-autophagy complex formation by disrupting the interaction between autophagy-specific factor, ATG14L, and the complex core unit Vps34-Beclin 1 in vitro. Also, it inhibits the nutrient starvation induced autophagy and diminished pro-autophagy PIK3C3/VPS34 complex containing either ATG14L or UVRAG in several cell lines. Our results strongly suggest that Thuja orientalis L. leave extract functions as an autophagy-specific inhibitor not decreasing the complex activity nor the protein level, but preventing protein-protein interaction between autophagy-specific factor (ATG14L and UVRAG) and PIK3C3/VPS34 complex core unit, Vps34-Beclin 1, thereby specifically depleting the pro-autophagy complex to inhibit autophagy.

Project description:Ubiquitination is an important reversible post-translational modification. Many viruses hijack the host ubiquitin system to enhance self-replication. In the present study, we found that Avibirnavirus VP3 protein was ubiquitinated during infection and supported virus replication by ubiquitination. Mass spectrometry and mutation analysis showed that VP3 was ubiquitinated at residues K73, K135, K158, K193, and K219. Virus rescue showed that ubiquitination at sites K73, K193, and K219 on VP3 could enhance the replication abilities of infectious bursal disease virus (IBDV), and that K135 was essential for virus survival. Binding of the zinc finger domain of TRAF6 (TNF receptor associated factor 6) to VP3 mediated K11- and K33-linked ubiquitination of VP3, which promoted its nuclear accumulation to facilitate virus replication. Additionally, VP3 could inhibit TRAF6-mediated NFKB/NF-κB (nuclear factor kappa B) activation and IFNB/IFN-β (interferon beta) production to evade host innate immunity by inducing TRAF6 autophagic degradation in an SQSTM1/p62 (sequestosome 1)-dependent manner. Our findings demonstrated a macroautophagic/autophagic mechanism by which Avibirnavirus protein VP3 blocked NFKB-mediated IFNB production by targeting TRAF6 during virus infection, and provided a potential drug target for virus infection control.Abbreviations: ATG: autophagy related; BafA1: bafilomycin A1; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; Cas9: CRISPR-associated protein 9; CHX: cycloheximide; Co-IP: co-immunoprecipitation; CRISPR: clustered regularly interspaced short palindromic repeats; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GST: glutathione S-transferase; IBDV: infectious bursal disease virus; IF: indirect immunofluorescence; IFNB/IFN-β: interferon beta; mAb: monoclonal antibody; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; MS: mass spectrometry; NFKB/NF-κB: nuclear factor kappa B; NBR1: NBR1 autophagy cargo receptor; OPTN: optineurin; pAb: polyclonal antibody; PRRs: pattern recognition receptors; RNF125: ring finger protein 125; RNF135/Riplet: ring finger protein 135; SQSTM1/p62: sequestosome 1; TAX1BP1: tax1 binding protein1; TCID50: 50% tissue culture infective dose; TRAF3: TNF receptor associated factor 3; TRAF6: TNF receptor associated factor 6; TRIM25: tripartite motif containing 25; Ub: ubiquitin; Wort: wortmannin; WT: wild type.

Dataset Information

Binding of Avibirnavirus VP3 to the PIK3C3-PDPK1 complex inhibits autophagy by activating the AKT-MTOR pathway.

Abbreviations

Publications

Binding of <i>Avibirnavirus</i> VP3 to the PIK3C3-PDPK1 complex inhibits autophagy by activating the AKT-MTOR pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets