scholarly journals Characterisation of the Semliki Forest Virus-host cell interactome reveals the viral capsid protein as an inhibitor of nonsense-mediated mRNA decay

2020 ◽  
Author(s):  
Lara Contu ◽  
Giuseppe Balistreri ◽  
Michal Domanski ◽  
Anne-Christine Uldry ◽  
Oliver Mühlemann
Keyword(s):  
Host Cell ◽  
Capsid Protein ◽  
Mrna Decay ◽  
Semliki Forest Virus ◽  
Protein Protein Interaction ◽  
Host Cell Proteins ◽  
Complex Interactions ◽  
Nonsense Mediated Mrna Decay ◽  
Interaction Map ◽  
The Many

AbstractThe positive-sense, single-stranded RNA alphaviruses pose a potential epidemic threat. Understanding the complex interactions between the viral and the host cell proteins is crucial for elucidating the mechanisms underlying successful virus replication strategies and for developing specific antiviral interventions. Here we present the first comprehensive protein-protein interaction map between the proteins of Semliki Forest Virus (SFV), a mosquito-borne member of the alphaviruses, and host cell proteins. Among the many identified cellular interactors of SFV proteins, the enrichment of factors involved in translation and nonsense-mediated mRNA decay (NMD) was striking, reflecting the virus’ hijacking of the translation machinery and indicating viral countermeasures for escaping NMD by inhibiting NMD at later time points during the infectious cycle. In addition to observing a general inhibition of NMD about 4 hours post infection, we also demonstrate that transient expression of the SFV capsid protein is sufficient to inhibit NMD in cells, suggesting that the massive production of capsid protein during the SFV reproduction cycle is responsible for NMD inhibition.

scholarly journals Characterisation of the Semliki Forest Virus-host cell interactome reveals the viral capsid protein as an inhibitor of nonsense-mediated mRNA decay

2021 ◽  
Vol 17 (5) ◽  
pp. e1009603
Author(s):  
Lara Contu ◽  
Giuseppe Balistreri ◽  
Michal Domanski ◽  
Anne-Christine Uldry ◽  
Oliver Mühlemann
Keyword(s):  
Host Cell ◽  
Capsid Protein ◽  
Mrna Decay ◽  
Semliki Forest Virus ◽  
Protein Protein Interaction ◽  
Host Cell Proteins ◽  
Complex Interactions ◽  
Nonsense Mediated Mrna Decay ◽  
Interaction Map ◽  
The Many

The positive-sense, single-stranded RNA alphaviruses pose a potential epidemic threat. Understanding the complex interactions between the viral and the host cell proteins is crucial for elucidating the mechanisms underlying successful virus replication strategies and for developing specific antiviral interventions. Here we present the first comprehensive protein-protein interaction map between the proteins of Semliki Forest Virus (SFV), a mosquito-borne member of the alphaviruses, and host cell proteins. Among the many identified cellular interactors of SFV proteins, the enrichment of factors involved in translation and nonsense-mediated mRNA decay (NMD) was striking, reflecting the virus’ hijacking of the translation machinery and indicating viral countermeasures for escaping NMD by inhibiting NMD at later time points during the infectious cycle. In addition to observing a general inhibition of NMD about 4 hours post infection, we also demonstrate that transient expression of the SFV capsid protein is sufficient to inhibit NMD in cells, suggesting that the massive production of capsid protein during the SFV reproduction cycle is responsible for NMD inhibition.

scholarly journals Nonsense-Mediated mRNA Decay: Pathologies and the Potential for Novel Therapeutics

Cancers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 765 ◽  
Author(s):  
Kamila Pawlicka ◽  
Umesh Kalathiya ◽  
Javier Alfaro
Keyword(s):  
Messenger Rna ◽  
Mrna Decay ◽  
Tumour Progression ◽  
Transcript Abundance ◽  
Tumour Suppressor Genes ◽  
Nonsense Mediated Mrna Decay ◽  
The Many ◽  
Cycle Regulation ◽  
Fine Tune

Nonsense-mediated messenger RNA (mRNA) decay (NMD) is a surveillance pathway used by cells to control the quality mRNAs and to fine-tune transcript abundance. NMD plays an important role in cell cycle regulation, cell viability, DNA damage response, while also serving as a barrier to virus infection. Disturbance of this control mechanism caused by genetic mutations or dys-regulation of the NMD pathway can lead to pathologies, including neurological disorders, immune diseases and cancers. The role of NMD in cancer development is complex, acting as both a promoter and a barrier to tumour progression. Cancer cells can exploit NMD for the downregulation of key tumour suppressor genes, or tumours adjust NMD activity to adapt to an aggressive immune microenvironment. The latter case might provide an avenue for therapeutic intervention as NMD inhibition has been shown to lead to the production of neoantigens that stimulate an immune system attack on tumours. For this reason, understanding the biology and co-option pathways of NMD is important for the development of novel therapeutic agents. Inhibitors, whose design can make use of the many structures available for NMD study, will play a crucial role in characterizing and providing diverse therapeutic options for this pathway in cancer and other diseases.

scholarly journals Quantitation of HLA Class II Protein Incorporated into Human Immunodeficiency Type 1 Virions Purified by Anti-CD45 Immunoaffinity Depletion of Microvesicles

2003 ◽  
Vol 77 (23) ◽  
pp. 12699-12709 ◽  
Author(s):  
Charles M. Trubey ◽  
Elena Chertova ◽  
Lori V. Coren ◽  
Joanne M. Hilburn ◽  
Catherine V. Hixson ◽  
...  
Keyword(s):  
Host Cell ◽  
Integral Membrane Protein ◽  
Class Ii ◽  
Hla Class Ii ◽  
Protein Sequencing ◽  
Molar Ratio ◽  
Host Cell Proteins ◽  
The Many ◽  
Hiv 1

ABSTRACT Among the many host cell-derived proteins found in human immunodeficiency virus type 1 (HIV-1), HLA class II (HLA-II) appears to be selectively incorporated onto virions and may contribute to mechanisms of indirect imunopathogenesis in HIV infection and AIDS. However, the amount of HLA-II on the surface of HIV-1 particles has not been reliably determined due to contamination of virus preparations by microvesicles containing host cell proteins, including HLA-II. Even rigorous sucrose density centrifugation is unable to completely separate HIV-1 from microvesicles. CD45, a leukocyte integral membrane protein, is found on microvesicles, yet appears to be excluded from HIV-1 particles. Exploiting this observation, we have developed a CD45-based immunoaffinity depletion method for removing CD45-containing microvesicles that yields highly purified preparations of virions. Examination of CD45-depleted HIV-1MN by high-pressure liquid chromatography, protein sequencing, and amino acid analyses determined a molar ratio of HLA-II to Gag of 0.04 to 0.05 in the purified virions, corresponding to an estimated average of 50 to 63 native HLA-II complexes (i.e., a dimer of α and β heterodimers) per virion. These values are approximately 5- to 10-fold lower than those previously determined for other virion preparations that contained microvesicles. Our observations demonstrate the utility of CD45 immunoaffinity-based approaches for producing highly purified retrovirus preparations for applications that would benefit from the use of virus that is essentially free of microvesicles.

scholarly journals The Cellular NMD Pathway Restricts Zika Virus Infection and Is Targeted by the Viral Capsid Protein

mBio ◽  
2018 ◽  
Vol 9 (6) ◽  
Author(s):  
Krystal A. Fontaine ◽  
Kristoffer E. Leon ◽  
Mir M. Khalid ◽  
Sakshi Tomar ◽  
David Jimenez-Morales ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Zika Virus ◽  
Neurological Disorders ◽  
Mrna Decay ◽  
Neural Progenitor ◽  
Viral Capsid ◽  
Zikv Infection ◽  
Viral Capsid Protein ◽  
Quality Control Process ◽  
Nonsense Mediated Mrna Decay

ABSTRACT Zika virus (ZIKV) infection of neural progenitor cells (NPCs) in utero is associated with neurological disorders, such as microcephaly, but a detailed molecular understanding of ZIKV-induced pathogenesis is lacking. Here we show that in vitro ZIKV infection of human cells, including NPCs, causes disruption of the nonsense-mediated mRNA decay (NMD) pathway. NMD is a cellular mRNA surveillance mechanism that is required for normal brain size in mice. Using affinity purification-mass spectrometry, we identified multiple cellular NMD factors that bind to the viral capsid protein, including the central NMD regulator up-frameshift protein 1 (UPF1). Endogenous UPF1 interacted with the ZIKV capsid protein in coimmunoprecipitation experiments, and capsid expression posttranscriptionally downregulated UPF1 protein levels, a process that we confirmed occurs during ZIKV infection. Cellular fractionation studies show that the ZIKV capsid protein specifically targets nuclear UPF1 for degradation via the proteasome. A further decrease in UPF1 levels by RNAi significantly enhanced ZIKV infection in NPC cultures, consistent with a model in which NMD restricts ZIKV infection in the fetal brain. We propose that ZIKV, via the capsid protein, has evolved a strategy to lower UPF1 levels and dampen antiviral activities of NMD, which in turn contributes to neuropathology in vivo. IMPORTANCE Zika virus (ZIKV) is a significant global health threat, as infection has been linked to serious neurological complications, including microcephaly. Using a human stem cell-derived neural progenitor model system, we find that a critical cellular quality control process called the nonsense-mediated mRNA decay (NMD) pathway is disrupted during ZIKV infection. Importantly, disruption of the NMD pathway is a known cause of microcephaly and other neurological disorders. We further identify an interaction between the capsid protein of ZIKV and up-frameshift protein 1 (UPF1), the master regulator of NMD, and show that ZIKV capsid targets UPF1 for degradation. Together, these results offer a new mechanism for how ZIKV infection can cause neuropathology in the developing brain.

Sign in / Sign up

Export Citation Format

Share Document