tetano
Editor, Senior Moderator
Biochem Biophys Res Commun
. 2020 Aug 20;529(2):251-256.
doi: 10.1016/j.bbrc.2020.06.058. Epub 2020 Jun 16.
Proteasome activator PA28γ-dependent degradation of coronavirus disease (COVID-19) nucleocapsid protein
Haiyang Zhang[SUP] 1 [/SUP], Jialu Tu[SUP] 1 [/SUP], Chulei Cao[SUP] 1 [/SUP], Ting Yang[SUP] 1 [/SUP], Liangcai Gao[SUP] 2 [/SUP]
Affiliations
Abstract
The nucleocapsid protein is significant in the formation of viral RNA of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), accounting for the largest proportion of viral structural proteins. Here, we report for the first time that the 11S proteasomal activator PA28γ regulates the intracellular abundance of the SARS-CoV-2 N protein (nCoV N). Furthermore, we have identified proteasome activator PA28γ as a nCoV N binding protein by co-immunoprecipitation assay. As a result of their interaction, nCoV N could be degraded by PA28γ-20S in vitro degradation assay. This was also demonstrated by blocking de novo protein synthesis with cycloheximide. The stability of nCoV N in PA28γ-knockout cells was greater than in PA28γ-wildtype cells. Notably, immunofluorescence staining revealed that knockout of the PA28γ gene in cells led to the transport of nCoV N from the nucleus to the cytoplasm. Overexpression of PA28γ enhanced proteolysis of nCoV N compared to that in PA28γ-N151Y cells containing a dominant-negative PA28γ mutation, which reduced this process. These results suggest that PA28γ binding is important in regulating 20S proteasome activity, which in turn regulates levels of the critical nCoV N nucleocapsid protein of SARS-CoV-2, furthering our understanding of the pathogenesis of COVID-19.
Keywords: COVID-19; PA28γ; Protein degradation; SARS-CoV-2; nCoV N.
. 2020 Aug 20;529(2):251-256.
doi: 10.1016/j.bbrc.2020.06.058. Epub 2020 Jun 16.
Proteasome activator PA28γ-dependent degradation of coronavirus disease (COVID-19) nucleocapsid protein
Haiyang Zhang[SUP] 1 [/SUP], Jialu Tu[SUP] 1 [/SUP], Chulei Cao[SUP] 1 [/SUP], Ting Yang[SUP] 1 [/SUP], Liangcai Gao[SUP] 2 [/SUP]
Affiliations
- PMID: 32703419
- DOI: 10.1016/j.bbrc.2020.06.058
Abstract
The nucleocapsid protein is significant in the formation of viral RNA of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), accounting for the largest proportion of viral structural proteins. Here, we report for the first time that the 11S proteasomal activator PA28γ regulates the intracellular abundance of the SARS-CoV-2 N protein (nCoV N). Furthermore, we have identified proteasome activator PA28γ as a nCoV N binding protein by co-immunoprecipitation assay. As a result of their interaction, nCoV N could be degraded by PA28γ-20S in vitro degradation assay. This was also demonstrated by blocking de novo protein synthesis with cycloheximide. The stability of nCoV N in PA28γ-knockout cells was greater than in PA28γ-wildtype cells. Notably, immunofluorescence staining revealed that knockout of the PA28γ gene in cells led to the transport of nCoV N from the nucleus to the cytoplasm. Overexpression of PA28γ enhanced proteolysis of nCoV N compared to that in PA28γ-N151Y cells containing a dominant-negative PA28γ mutation, which reduced this process. These results suggest that PA28γ binding is important in regulating 20S proteasome activity, which in turn regulates levels of the critical nCoV N nucleocapsid protein of SARS-CoV-2, furthering our understanding of the pathogenesis of COVID-19.
Keywords: COVID-19; PA28γ; Protein degradation; SARS-CoV-2; nCoV N.