A rational strategy was introduced for the synthesis of a novel dual functionalized metal–organic framework nanocomposite (AuGC/ZIF-8) with ultra-hydrophilicity to enhance glycopeptide enrichment.
MERS is a life-threatening disease and MERS-CoV has the potential to cause the next pandemic. Protein acetylation is known to play a crucial role in host response to viral infection. Acetylation of viral proteins encoded by other RNA viruses have been reported to affect viral replication. It is therefore of interest to see whether MERS-CoV proteins are also acetylated. Viral proteins obtained from infected cells were trypsin-digested into peptides. Acetylated peptides were enriched by immunoprecipitation and subject to nano-LC-Orbitrap analysis. Bioinformatic analysis was performed to assess the conservation level of identified acetylation sites and to predict the upstream regulatory factors. A total of 12 acetylation sites were identified from 7 peptides, which all belong to the replicase polyprotein pp1ab. All identified acetylation sites were found to be highly conserved across MERS-CoV sequences in NCBI database. Upstream factors, including deacetylases of the SIRT1 and HDAC families as well as acetyltransferases of the TIP60 family, were predicted to be responsible for regulating the acetylation events identified. Western blot confirms that acetylation events indeed occur on pp1ab protein by expressing NSP4 in HEK293 cells. Acetylation events on MERS-CoV viral protein pp1ab were identified for the first time, which indicate that MERS-CoV might use the host acetylation machinery to regulate its enzyme activity and to achieve optimal replication. Upstream factors were predicted, which might facilitate further analysis of the regulatory mechanism of MERS-CoV replication.
Currently, there is no effective antiviral medication for coronavirus disease 2019 and the knowledge on the potential therapeutic target is in great need. Guided by a time-course transmission electron microscope (TEM) imaging, we analyzed early phosphorylation dynamics within the first 15 min during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral entry. Based on alterations in the phosphorylation events, we found that kinase activities such as protein kinase C (PKC), interleukin-1 receptor-associated kinase 4 (IRAK4), MAP/microtubule affinity-regulating kinase 3 (MARK3), and TANK-binding kinase 1 (TBK1) were affected within 15 min of infection. Application of the corresponding kinase inhibitors of PKC, IRAK4, and p38 showed significant inhibition of SARS-CoV-2 replication. Additionally, proinflammatory cytokine production was reduced by applying PKC and p38 inhibitors. By an acquisition of a combined image data using positiveand negative-sense RNA probes, as well as pseudovirus entry assay, we demonstrated that PKC contributed to viral entry into the host cell, and therefore, could be a potential COVID-19 therapeutic target.
1‐Nitropyrene (1‐NP) is one of the most representative diesel exhaust‐sourced components existing in fine particulate matter (PM2.5) and a potential carcinogen. 1‐NP demonstrates a significant higher cytotoxicity than its structural analogs and precursor. Herein, 1‐NP with its structural analog 3‐nitrofluoranthene and precursor pyrene in human lung epithelial cell lines are compared. An acute reactive oxygen species (ROS) accompanied with cell death is observed for 1‐NP. Using compound‐centric redox proteomics analysis, it is shown that 1‐NP significantly remodeled the redox proteome and specifically targeted on ROS reduction pathway. Superoxide dismutase 1 (SOD1) is identified as a potential target. It is demonstrated that 1‐NP directly acts on cysteine residue Cys111 and inhibits SOD activity. The position of nitroxide determines its direct target and contributes to the unique mechanism of 1‐NP. A novel mechanism for 1‐NP cytotoxicity and ROS induction is therefore proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.