Mass spectrometry detection of monkeypox virus: Comprehensive coverage for ranking the most responsive peptide markers

Sample Preparation and Processing for Quick, Universal, and Insightful Microbial Proteomics

Next-generation shotgun proteomics is one of the most valuable tools for gaining insight into the function of organisms. By providing a list of peptides and abundance information, proteomics enables the identification of proteins, their quantities, posttranslational modifications, and localization. The most refined shotgun proteomics workflow involves protein extraction, trypsin digestion, ultrahigh-performance liquid chromatography coupled to high-resolution tandem mass spectrometry, and confident assignment of resulting spectra to peptide sequences. In this study, we present a versatile, time- and cost-efficient experimental workflow for protein extraction, digestion, and analysis that can be applied to any type of microorganism. Our experimental procedure exhibits superior sensitivity compared to gel-based protocols and can be used for comparative microbial proteomics to highlight key players that explain phenotypic differences between conditions or for proteotyping new microbial isolates for taxonomic purposes.

Metaproteomic analysis of King Ghezo tomb wall (Abomey, Benin) confirms 19th century voodoo sacrifices

The palace of King Ghezo in Abomey, capital of the ancient kingdom of Dahomey (present-day Benin), houses two sacred huts which are specific funerary structures. It is claimed that the binder in their walls is made of human blood. In the study presented here, we conceived an original strategy to analyze the proteins present on minute amounts of the cladding sampled from the inner facade of the cenotaph wall and establish their origin. The extracted proteins were proteolyzed and the resulting peptides were characterized by high-resolution tandem mass spectrometry. Over 6397 distinct molecular entities were identified using cascading searches. Starting from without a priori searches of an extended generic database, the peptide repertoire was narrowed down to the most representative organisms-identified by means of taxon-specific peptides. A wide diversity of bacteria, fungi, plants, and animals were detected through the available protein material. This inventory was used to archaeologically reconstruct the voodoo rituals of consecration and maintenance of vitality. Several indicators attested to the presence of traces of human and poultry blood in the material taken. This study shows the essential advantages of paleoproteomics and metaproteomics for the study of ancient residues from archaeological excavations or historical monuments.

Methionine oxidation of carbohydrate-active enzymes during white-rot wood decay

White-rot fungi employ secreted carbohydrate-active enzymes (CAZymes) along with reactive oxygen species (ROS), like hydrogen peroxide (H2O2), to degrade lignocellulose in wood. H2O2 serves as a co-substrate for key oxidoreductases during the initial decay phase. While the degradation of lignocellulose by CAZymes is well documented, the impact of ROS on the oxidation of the secreted proteins remains unclear, and the identity of the oxidized proteins is unknown. Methionine (Met) can be oxidized to Met sulfoxide (MetO) or Met sulfone (MetO2) with potential deleterious, antioxidant, or regulatory effects. Other residues, like proline (Pro), can undergo carbonylation. Using the white-rot Pycnoporus cinnabarinus grown on aspen wood, we analyzed the Met content of the secreted proteins and their susceptibility to oxidation combining H218O2 with deep shotgun proteomics. Strikingly, their overall Met content was significantly lower (1.4%) compared to intracellular proteins (2.1%), a feature conserved in fungi but not in metazoans or plants. We evidenced that a catalase, widespread in white-rot fungi, protects the secreted proteins from oxidation. Our redox proteomics approach allowed the identification of 49 oxidizable Met and 40 oxidizable Pro residues within few secreted proteins, mostly CAZymes. Interestingly, many of them had several oxidized residues localized in hotspots. Some Met, including those in GH7 cellobiohydrolases, were oxidized up to 47%, with a substantial percentage of sulfone (13%). These Met are conserved in fungal homologs, suggesting important functional roles. Our findings reveal that white-rot fungi safeguard their secreted proteins by minimizing their Met content and by scavenging ROS and pinpoint redox-active residues in CAZymes.IMPORTANCEThe study of lignocellulose degradation by fungi is critical for understanding the ecological and industrial implications of wood decay. While carbohydrate-active enzymes (CAZymes) play a well-established role in lignocellulose degradation, the impact of hydrogen peroxide (H2O2) on secreted proteins remains unclear. This study aims at evaluating the effect of H2O2 on secreted proteins, focusing on the oxidation of methionine (Met). Using the model white-rot fungi Pycnoporus cinnabarinus grown on aspen wood, we showed that fungi protect their secreted proteins from oxidation by reducing their Met content and utilizing a secreted catalase to scavenge exogenous H2O2. The research identified key oxidizable Met within secreted CAZymes. Importantly, some Met, like those of GH7 cellobiohydrolases, undergone substantial oxidation levels suggesting important roles in lignocellulose degradation. These findings highlight the adaptive mechanisms employed by white-rot fungi to safeguard their secreted proteins during wood decay and emphasize the importance of these processes in lignocellulose breakdown.

Transcriptome and proteomic analysis of mpox virus F3L-expressing cells

Background

Monkeypox or mpox virus (mpox) is a double-stranded DNA virus that poses a significant threat to global public health security. The F3 protein, encoded by mpox, is an apoenzyme believed to possess a double-stranded RNA-binding domain (dsRBD). However, limited research has been conducted on its function. In this study, we present data on the transcriptomics and proteomics of F3L-transfected HEK293T cells, aiming to enhance our comprehension of F3L.

Methods

The gene expression profiles of pCAGGS-HA-F3L transfected HEK293T cells were analyzed using RNA-seq. Proteomics was used to identify and study proteins that interact with F3L. Real-time PCR was used to detect mRNA levels of several differentially expressed genes (DEGs) in HEK293T cells (or Vero cells) after the expression of F3 protein.

Results

A total of 14,822 genes were obtained in cells by RNA-Seq and 1,672 DEGs were identified, including 1,156 up-regulated genes and 516 down-regulated genes. A total of 27 cellular proteins interacting with F3 proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and 19 cellular proteins with large differences in abundance ratios were considered to be candidate cellular proteins. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the DEGs were significantly enriched in immune-related pathways, including type I interferon signaling pathway, response to virus, RIG-I-like receptor signaling pathway, NOD-like receptor signaling pathway, etc. Moreover, some selected DEGs were further confirmed by real-time PCR and the results were consistent with the transcriptome data. Proteomics data show that cellular proteins interacting with F3 proteins are mainly related to RNA splicing and protein translation.

Conclusions

Our analysis of transcriptomic and proteomic data showed that (1) F3L up-regulates the transcript levels of key genes in the innate immune signaling pathway, such as RIGI, MDA5, IRF5, IRF7, IRF9, ISG15, IFNA14, and elicits a broad spectrum of antiviral immune responses in the host. F3L also increases the expression of the FOS and JNK genes while decreasing the expression of TNFR2, these factors may ultimately induce apoptosis. (2) F3 protein interacts with host proteins involved in RNA splicing and protein translation, such as SNRNP70, POLR2H, HNRNPA1, DDX17, etc. The findings of this study shed light on the function of the F3 protein.

Organ-oriented proteogenomics functional atlas of three aquatic invertebrate sentinel species

Proteogenomic methodologies have enabled the identification of protein sequences in wild species without annotated genomes, shedding light on molecular mechanisms affected by pollution. However, proteomic resources for sentinel species are limited, and organ-level investigations are necessary to expand our understanding of their molecular biology. This study presents proteomic resources obtained from proteogenomic analyses of key organs (hepatopancreas, gills, hemolymph) from three established aquatic sentinel invertebrate species of interest in ecotoxicological/ecological research and environmental monitoring: Gammarus fossarum, Dreissena polymorpha, and Palaemon serratus. Proteogenomic analyses identified thousands of proteins for each species, with over 90% of them being annotated to putative function. Functional analysis validated the relevance of the proteomic atlases by revealing similarities in functional annotation of catalogues of proteins across analogous organs in the three species, while deep contrasts between functional profiles are delimited across different organs in the same organism. These organ-level proteomic atlases are crucial for future research on these sentinel animals, aiding in the evaluation of aquatic environmental risks and providing a valuable resource for ecotoxicological studies.

Oral Infection, Oral Pathology and Salivary Diagnostics of Mpox Disease: Relevance in Dentistry and OMICs Perspectives

In this narrative review, we aim to point out the close relationship between mpox virus (MPXV) infection and the role of saliva as a diagnostic tool for mpox, considering the current molecular approach and in the perspective of OMICs application. The MPXV uses the host cell's rough endoplasmic reticulum, ribosomes, and cytoplasmic proteins to replicate its genome and synthesize virions for cellular exit. The presence of oral mucosa lesions associated with mpox infection is one of the first signs of infection; however, current diagnostic tools find it difficult to detect the virus before the rashes begin. MPXV transmission occurs through direct contact with an infected lesion and infected body fluids, including saliva, presenting a potential use of this fluid for diagnostic purposes. Currently available diagnostic tests for MPXV detection are performed either by real-time quantitative PCR (RT-qPCR) or ELISA, which presents several limitations since they are invasive tests. Despite current clinical trials with restricted sample size, MPXV DNA was detected in saliva with a sensitivity of 85%-100%. In this context, the application of transcriptomics, metabolomics, lipidomics, or proteomics analyses coupled with saliva can identify novel disease biomarkers. Thus, it is important to note that the identification and quantification of salivary DNA, RNA, lipid, protein, and metabolite can provide novel non-invasive biomarkers through the use of OMICs platforms aiding in the early detection and diagnosis of MPXV infection. Untargeted mass spectrometry (MS)-based proteomics reveals that some proteins also expressed in saliva were detected with greater expression differences in blood plasma when comparing mpox patients and healthy subjects, suggesting a promising alternative to be applied in screening or diagnostic platforms for mpox salivary diagnostics coupled to OMICs.

Insights into peculiar fungal LPMO family members holding a short C-terminal sequence reminiscent of phosphate binding motifs

Lytic polysaccharide monooxygenases (LPMOs) are taxonomically widespread copper-enzymes boosting biopolymers conversion (e.g. cellulose, chitin) in Nature. White-rot Polyporales, which are major fungal wood decayers, may possess up to 60 LPMO-encoding genes belonging to the auxiliary activities family 9 (AA9). Yet, the functional relevance of such multiplicity remains to be uncovered. Previous comparative transcriptomic studies of six Polyporales fungi grown on cellulosic substrates had shown the overexpression of numerous AA9-encoding genes, including some holding a C-terminal domain of unknown function ("X282"). Here, after carrying out structural predictions and phylogenetic analyses, we selected and characterized six AA9-X282s with different C-term modularities and atypical features hitherto unreported. Unexpectedly, after screening a large array of conditions, these AA9-X282s showed only weak binding properties to cellulose, and low to no cellulolytic oxidative activity. Strikingly, proteomic analysis revealed the presence of multiple phosphorylated residues at the surface of these AA9-X282s, including a conserved residue next to the copper site. Further analyses focusing on a 9 residues glycine-rich C-term extension suggested that it could hold phosphate-binding properties. Our results question the involvement of these AA9 proteins in the degradation of plant cell wall and open new avenues as to the divergence of function of some AA9 members.

Deep Paleoproteotyping and Microtomography Revealed No Heart Defect nor Traces of Embalming in the Cardiac Relics of Blessed Pauline Jaricot

Scientific examination of the heart of Blessed Pauline Jaricot-a French missionary figure-was carried out in 2022. As tandem mass spectrometry proteotyping has proven to be valuable to obtain the broad taxonomic repertoire of a given sample without any a priori information, we aimed at exploring the conditions of preservation of the relics and possible conditions of death. Metaproteomics and high-resolution microtomography imaging approaches were combined. A dataset comprising 6731 high-resolution MS/MS spectra was acquired and 968 of these spectra could be assigned to specific peptidic biomolecules. Based on the taxonomical information encompassed by the identified peptide sequences, 5 phyla were identified amongst eukaryota (94% of the biomass): Ascomycota (55%), with the species Aspergillus versicolor, Trichophyton mentagrophytes and Aspergillus glaucus, corresponding to expected cadaverous fungal flora; Chordata (42%), represented by a unique species, Homo sapiens; Streptophyta (3%); and Arthropoda (traces). Bacteria (6% of the biomass) were poorly represented. No trace of embalming substance could be retrieved, nor any pathogens. Imaging evidenced no heart defect nor embalming traces. No evidence that was inconsistent with natural and spontaneous conservation could be retrieved. This study prefigures the power of modern molecular techniques such as paleoproteotyping coupled to microtomography to gain insight into historical relics.

The pathophysiological and immunological background of the monkeypox virus infection: An update

In addition to the COVID-19 waves, the globe is facing global monkeypox (MPX) outbreak. MPX is an uncommon zoonotic infection characterized by symptoms similar to smallpox. It is caused by the monkeypox virus (MPXV), a double-stranded DNA virus that belongs to the genus Orthopoxvirus (OPXV). MPXV, which causes human disease, has been confined to Africa for many years, with only a few isolated cases in other areas. Outside of Africa, the continuing MPXV outbreak in multiple countries in 2022 is the greatest in recorded history. The current outbreak, with over 10 000 confirmed cases in over 50 countries between May and July 2022, demonstrates that MPXV may travel rapidly among humans and pose a danger to human health worldwide. The rapid spread of such outbreaks in recent times has elevated MPX to the status of a rising zoonotic disease with significant epidemic potential. While the MPXV is not as deadly or contagious as the variola virus that causes smallpox, it poses a threat because it could evolve into a more potent human pathogen. This review assesses the potential threat to the human population and provides a brief overview of what is currently known about this reemerging virus. By analyzing the biological effects of MPXV on human health, its shifting epidemiological footprint, and currently available therapeutic options, this review has presented the most recent insights into the biology of the virus. This study also clarifies the key potential causes that could be to blame for the present MPX outbreak and draw attention to major research questions and promising new avenues for combating the current MPX epidemic.