In a recent study published in the Proceedings of the National Academy of Sciences (PNAS), researchers evaluated the global succinylation of host cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Study: Global succinylation of SARS-CoV-2-infected host cells reveals drug targets. Image credit: Jezper / Shutterstock
Fund
Although vaccines against coronavirus disease 2019 (COVID-19) have played a key role in slowing the transmission of SARS-CoV-2, the decline in vaccine efficacy against new viral variants has become a matter of great concern. This has required the development of effective, broad-spectrum antiviral drugs against SARS-CoV-2 and its emerging variants.
About the study
In the present study, the researchers investigated the succinylation of host proteins and SARS-CoV-2 by succinylproteomic analysis based on quantitative mass spectrometry.
The team analyzed the effect of SARS-CoV-2 infection on post-translational modifications of the host protein (PTM) in the early stages of infection by determining viral infection conditions in Caco cells. -2. General profiles related to the five types of PTM were examined after SARS-CoV-2 infection, such as acetylation, lactoylation, malonylation, succinylation, and ubiquitination. In addition, the team collected Caco-2 cells in biological samples by tripling to zero, 12, and 24 hours after infection (hpi). Each sample was evaluated for variations in overall protein abundance, transcription, or succinylation. The infection group analyzed at zero hpi was used in all comparisons to estimate the fold changes corresponding to genes or proteins.
The interference probability of non-succinylated proteins was eliminated by comparing the observed fold changes to succinylated proteins and total proteins in abundance. In addition, the translation pattern of SARS-CoV-2 proteins was detected by analyzing the abundance of transcriptome and viral proteome observed at different times.
Results
The results of the study showed that protein succinylation was substantially regulated in the early stages of SARS-CoV-2 infection, which was positively associated with the period of infection. The team also observed that the number of host proteins decreased in abundance in the later stages of infection. In addition, the proportion of succinylated sites and proteins also increased, indicating that viral infection elicited a response from host succinylated proteins.
The team classified host succinylated proteins into four groups based on fold changes in abundance. This revealed that several succinylated proteins were present in the second cluster, indicating that succinylation levels of the host protein were positively associated with the viral infection process. This positive correlation was further verified by a deeper analysis of the nine protein abundance groups as well as the succinyl protein abundance during infection. In addition, the team noted that the abundance of succinylated proteins in the host was substantially regulated at 24 hpi, although the abundance of total proteins did not reveal any noticeable variation. This indicated that protein succinylation represented a crucial host response against COVID-19.
Detection of translation patterns showed that most viral transcripts were substantially regulated in the early stages of infection. Regarding viral abundance, the team observed that only four proteins, namely the SARS-CoV-2 membrane glycoprotein (M), the nucleocapsid (N), the open reading frame 3 (ORF3 ) and spike protein (S), were at detectable levels at detectable levels. 24 hpi. These results were consistent with the life cycle of SARS-CoV-2 in infected cells.
In addition, the team found that the modification in succinylation only occurred in N and M proteins at 24 hpi. On the other hand, both N and M proteins were in great abundance at 12 hpi, whereas succinyl modification was not detected at this point, indicating that succinylation of N and M proteins only occurred. after protein translation in the viral replication process. The team also observed that the succinylated sites located in the M protein were conserved in all SARS-like coronaviruses. This suggested that PTMs of SARS-CoV-2 proteins such as succinylation play a regulatory role in the viral replication process.
The researchers recognized that 1000 succinylated host proteins detected at 24 hpi, as well as 246 proteins were expressed differently. In addition, enrichment analysis revealed that succinylated host proteins showing positive regulation were also involved in pathways associated with proteasome, ribosome, and spliceosome metabolism, while downregulated proteins were involved. associated with systemic lupus erythematosus, neutrophil extracellular trap formation, alcoholism, and alcoholism. viral carcinogenesis.
Evaluation of succinylation inhibitors showed that ST1326, a carnitine palmitoyltransferase I (CPT1) inhibitor, showed antiviral activity in Caco-2 cells as well as in cells of the enzyme converting enzyme. angiotensin-2 (ACE-2) HEK293T. The adenosine monophosphate activated protein kinase (AMPK) inhibitor STO-609 also showed antiviral activity in Caco-2 cells, but comparatively lower antiviral activity in HEK293T-ACE2 cells.
Conclusion
Overall, the study’s findings showed that global succinylproteomic analysis could accurately reveal the impact of SARS-CoV-2 infection and the modification of viral protein succinylation on cell metabolic processes. · Host cells.