In-vitro acetylation of SARS-CoV and SARS-CoV-2 nucleocapsid proteins by human PCAF and GCN5

Abstract

Recently, the novel coronavirus (SARS-CoV-2), which has spread from China to the world, was declared a global public health emergency, which causes lethal respiratory infections. Acetylation of several proteins plays essential roles in various biological processes, such as viral infections. We reported that the nucleoproteins of influenza virus and Zaire Ebolavirus were acetylated, suggesting that these modifications contributed to the molecular events involved in viral replication. Similar to influenza virus and Ebolavirus, the coronavirus also contains single-stranded RNA, as its viral genome interacts with the nucleocapsid (N) proteins. In this study, we report that SARS-CoV and SARS-CoV-2 N proteins are strongly acetylated by human histone acetyltransferases, P300/CBP-associated factor (PCAF), and general control nonderepressible 5 (GCN5), but not by CREB-binding protein (CBP) in vitro . Liquid chromatography-mass spectrometry analyses identified 2 and 12 acetyl-lysine residues from SARS-CoV and SARS-CoV-2 N proteins, respectively. Particularly in the SARS-CoV-2 N proteins, the acetyl-lysine residues were localized in or close to several functional sites, such as the RNA interaction domains and the M-protein interacting site. These results suggest that acetylation of SARS-CoV-2 N proteins plays crucial roles in their functions.

N6-Acetyl-L-Lysine and p-Cresol as Key Metabolites in the Pathogenesis of COVID-19 in Obese Patients

“…Our analysis identified a set of metabolites that were significantly altered in COVID-19 overweight-obese patients when compared to COVID-19 lean patients. Data showed significantly upregulated levels of n6-acetyl-l-lysine ( p < 0.01; Figure 3A ), a metabolite that belongs to a class of organic compounds known as l-alpha-amino acids ( 34 ), and is known for its role in chronic inflammation and viral function induction ( 34 , 35 ). In addition to n6-acetyl-l-lysine, data showed significantly upregulated levels of the protein-bound uremic retention solute p-cresol ( p < 0.05) in COVID-19 overweight-obese patients when compared to COVID-19 lean patients ( Figure 3B ).…”

“…Similarly, SARS-CoV and SARS-CoV-2 N proteins are shown to be strongly acetylated by human histone acetyltransferases, forming acetyl-lysine residues. These acetylated lysine residues are mainly localized at the N- terminal and C-terminal functional interacting sites of RNA and the membrane (M)-protein ( 35 ), which was shown to play a role in viral infectivity and antigenicity ( 42 ). Although the bi-directional virus-host and chromatin regulation are not yet fully understood, histone modifications have been proven to affect viral chromatin which possibly influence epigenetic factors that mediate viral survival and function, allowing it to escape the immune system ( 43 ).…”

Point-of-care diagnosis of COVID-19 disease based on antigen tests

“…N protein (55,56), S protein (57-59) and M protein (60) are the most common targets for an antigen assay. A wide number of assays can be covered under the term antigen or antigenic tests and assays like ELISA (61) can be used for the antigen tests and chromatographic and mass spectrometry assays (62)(63)(64)(65) are also suitable for the assay purpose; however, lateral fl ow tests (or lateral fl ow immunochromatographic assay or lateral fl ow immunochromatography) are relevant in the current clinical praxis of COVID-19 diagnosis (66). The lateral fl ow tests are also well suited for the point-of-care conditions.…”

Acetylation of the influenza A virus polymerase subunit PA in the N‐terminal domain positively regulates its endonuclease activity

“…Moreover, several viral proteins represent targets of acetylation, such as the Tat protein of HIV [5], the latency-Abbreviations CBB, Coomassie Brilliant Blue; CBP, CREB-binding protein; GCN5, general control nonderepressible 5; HATs, histone acetyltransferases; LC-MS/MS, liquid chromatography with tandem mass spectrometry; MDCK, Madin-Darby canine kidney; NP, nucleoprotein; PCAF, P300/CBP-associated factor; SEM, standard error of the mean; SWATH, sequential window acquisition of all theoretical fragment ion spectra; TwST, Twin-Strep-tagÒ. associated nuclear antigen of Kaposi's sarcomaassociated herpesvirus [6], the E2 protein of human papillomavirus [7,8], the replicase polyprotein pp1ab of MERS coronavirus [9], capsid proteins of recombinant adeno-associated virus [10], foamy virus transactivator Tas [11], nucleoprotein (NP) and VP40 of Zaire ebolavirus [12], and SARS-CoV and SARS-CoV-2 nucleocapsid proteins [13].…”

“…Numerous nonhistone proteins can also serve as targets of acetylation; this phenomenon is widely involved in biological processes, including metabolism, cancer, and memory consolidation [2–4]. Moreover, several viral proteins represent targets of acetylation, such as the Tat protein of HIV [5], the latency‐associated nuclear antigen of Kaposi's sarcoma‐associated herpesvirus [6], the E2 protein of human papillomavirus [7,8], the replicase polyprotein pp1ab of MERS coronavirus [9], capsid proteins of recombinant adeno‐associated virus [10], foamy virus transactivator Tas [11], nucleoprotein (NP) and VP40 of Zaire ebolavirus [12], and SARS‐CoV and SARS‐CoV‐2 nucleocapsid proteins [13].…”