scholarly journals Cell-penetrating peptide inhibits retromer-mediated human papillomavirus trafficking during virus entry

2020 ◽  
Vol 117 (11) ◽  
pp. 6121-6128 ◽  
Author(s):  
Pengwei Zhang ◽  
Ruben Moreno ◽  
Paul F. Lambert ◽  
Daniel DiMaio

Virus replication requires critical interactions between viral proteins and cellular proteins that mediate many aspects of infection, including the transport of viral genomes to the site of replication. In human papillomavirus (HPV) infection, the cellular protein complex known as retromer binds to the L2 capsid protein and sorts incoming virions into the retrograde transport pathway for trafficking to the nucleus. Here, we show that short synthetic peptides containing the HPV16 L2 retromer-binding site and a cell-penetrating sequence enter cells, sequester retromer from the incoming HPV pseudovirus, and inhibit HPV exit from the endosome, resulting in loss of viral components from cells and in a profound, dose-dependent block to infection. The peptide also inhibits cervicovaginal HPV16 pseudovirus infection in a mouse model. These results confirm the retromer-mediated model of retrograde HPV entry and validate intracellular virus trafficking as an antiviral target. More generally, inhibiting virus replication with agents that can enter cells and disrupt essential protein-protein interactions may be applicable in broad outline to many viruses.

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1864
Author(s):  
Isabel Pagani ◽  
Guido Poli ◽  
Elisa Vicenzi

Viral invasion of target cells triggers an immediate intracellular host defense system aimed at preventing further propagation of the virus. Viral genomes or early products of viral replication are sensed by a number of pattern recognition receptors, leading to the synthesis and production of type I interferons (IFNs) that, in turn, activate a cascade of IFN-stimulated genes (ISGs) with antiviral functions. Among these, several members of the tripartite motif (TRIM) family are antiviral executors. This article will focus, in particular, on TRIM22 as an example of a multitarget antiviral member of the TRIM family. The antiviral activities of TRIM22 against different DNA and RNA viruses, particularly human immunodeficiency virus type 1 (HIV-1) and influenza A virus (IAV), will be discussed. TRIM22 restriction of virus replication can involve either direct interaction of TRIM22 E3 ubiquitin ligase activity with viral proteins, or indirect protein–protein interactions resulting in control of viral gene transcription, but also epigenetic effects exerted at the chromatin level.


2021 ◽  
Vol 17 (5) ◽  
pp. e1008988
Author(s):  
Nikolina ŠoŠtarić ◽  
Vera van Noort

Post-translational modifications (PTMs) play a vital, yet often overlooked role in the living cells through modulation of protein properties, such as localization and affinity towards their interactors, thereby enabling quick adaptation to changing environmental conditions. We have previously benchmarked a computational framework for the prediction of PTMs’ effects on the stability of protein-protein interactions, which has molecular dynamics simulations followed by free energy calculations at its core. In the present work, we apply this framework to publicly available data on Saccharomyces cerevisiae protein structures and PTM sites, identified in both normal and stress conditions. We predict proteome-wide effects of acetylations and phosphorylations on protein-protein interactions and find that acetylations more frequently have locally stabilizing roles in protein interactions, while the opposite is true for phosphorylations. However, the overall impact of PTMs on protein-protein interactions is more complex than a simple sum of local changes caused by the introduction of PTMs and adds to our understanding of PTM cross-talk. We further use the obtained data to calculate the conformational changes brought about by PTMs. Finally, conservation of the analyzed PTM residues in orthologues shows that some predictions for yeast proteins will be mirrored to other organisms, including human. This work, therefore, contributes to our overall understanding of the modulation of the cellular protein interaction networks in yeast and beyond.


Author(s):  
Caroline Benz ◽  
Eszter Kassa ◽  
Elias Tjärnhage ◽  
Sara Bergström Lind ◽  
Ylva Ivarsson

2019 ◽  
Author(s):  
Christina K. Kim ◽  
Kelvin F. Cho ◽  
Min Woo Kim ◽  
Alice Y. Ting

Technologies that convert transient protein-protein interactions (PPIs) into stable expression of a reporter gene are useful for genetic selections, high-throughput screening, and multiplexing with omics technologies. We previously reported SPARK (Kim et al., 2017), a transcription factor that is activated by the coincidence of blue light and a PPI. Here, we report an improved, second-generation SPARK2 that incorporates a luciferase moiety to control the light-sensitive LOV domain. SPARK2 can be temporally gated by either external light or addition of a small-molecule luciferin, which causes luciferase to open LOV via proximity-dependent BRET. Furthermore, the nested “AND” gate design of SPARK2—in which both protease recruitment to the membrane-anchored transcription factor and LOV domain opening are regulated by the PPI of interest—yields a lower-background system and improved PPI specificity. We apply SPARK2 to high-throughput screening for GPCR agonists and for the detection of trans-cellular contacts, all with versatile transcriptional readout.


2020 ◽  
Vol 21 (21) ◽  
pp. 7980
Author(s):  
Guillem Dayer ◽  
Mehran L. Masoom ◽  
Melissa Togtema ◽  
Ingeborg Zehbe

High-risk strains of human papillomavirus are causative agents for cervical and other mucosal cancers, with type 16 being the most frequent. Compared to the European Prototype (EP; A1), the Asian-American (AA; D2/D3) sub-lineage seems to have increased abilities to promote carcinogenesis. Here, we studied protein–protein interactions (PPIs) between host proteins and sub-lineages of the key transforming E6 protein. We transduced human keratinocyte with EP or AA E6 genes and co-immunoprecipitated E6 proteins along with interacting cellular proteins to detect virus–host binding partners. AAE6 and EPE6 may have unique PPIs with host cellular proteins, conferring gain or loss of function and resulting in varied abilities to promote carcinogenesis. Using liquid chromatography-mass spectrometry and stringent interactor selection criteria based on the number of peptides, we identified 25 candidates: 6 unique to AAE6 and EPE6, along with 13 E6 targets common to both. A novel approach based on pathway selection discovered 171 target proteins: 90 unique AAE6 and 61 unique EPE6 along with 20 common E6 targets. Interpretations were made using databases, such as UniProt, BioGRID, and Reactome. Detected E6 targets were differentially implicated in important hallmarks of cancer: deregulating Notch signaling, energetics and hypoxia, DNA replication and repair, and immune response.


2019 ◽  
Author(s):  
Ageo Miccoli ◽  
Binar A. Dhiani ◽  
Peter J. Thornton ◽  
Olivia A. Lambourne ◽  
Edward James ◽  
...  

Many cellular protein-protein interactions (PPIs) are mediated by phosphoserine. The specific targeting of these PPIs by phosphoserine-containing small molecules has been scarce due to the dephosphorylation of phosphoserine and its charged nature at physiological pH, which hinders its uptake into cells. To address these issues, we herein report the masking of the phosphate group of phosphoserine with biocleavable aryloxy triester phosphoramidate groups. A combination of <i>in vitro</i> enzymatic assays and <i>in silico</i> studies, using carboxypeptidase Y and Hint-1 respectively, showed that the phosphate masking groups are metabolized to release phosphoserine. To probe the applicability of this phosphoserine masking approach, it was applied to a phosphoserine-containing inhibitor of 14-3-3 dimerization, and this generated molecules with improved pharmacological activity in cells compared to their unmasked phosphoserine-containing parent compound. Collectively, the data showcases the masking of phosphoserine with biocleavable aryloxy triester phosphoramidate masking groups as an efficient intracellular delivery system for phosphoserine-containing molecules.


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