The evolution of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in mutations not only in the spike protein,aiding immune evasion,but also in the NSP3/4/6 proteins,crucial for regulating double...The evolution of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in mutations not only in the spike protein,aiding immune evasion,but also in the NSP3/4/6 proteins,crucial for regulating double-membrane vesicle(DMV)formation.However,the functional consequences of these NSP3/4/6 mutations remain poorly understood.In this study,a systematic analysis was conducted to investigate the evolutionary patterns of NSP3/4/6 mutations and their impact on DMV formation.The findings revealed that the NSP4 T492I mutation,a prevalent mutation found in all Delta and Omicron sub-lineages,notably enhances DMV formation.Mechanistically,the NSP4 T492I mutation enhances its homodimerization,leading to an increase in the size of puncta induced by NSP3/4,and also augments endoplasmic reticulum(ER)membrane curvature,resulting in a higher DMV density per fluorescent puncta.This study underscores the significance of the NSP4 T492I mutation in modulating DMV formation,with potential implications for the transmission dynamics of SARS-CoV-2.It contributes valuable insights into how these mutations impact viral replication and pathogenesis.展开更多
基金supported by the National Natural Science Foundation of China(92469107 to Z.Li)the R&D Program of Guangzhou National Laboratory(ZL-SRPG2200205 to Z.Li)the Guangdong Province High-level Talent Youth Project(2021QN02Y939 to Z.Li).
文摘The evolution of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in mutations not only in the spike protein,aiding immune evasion,but also in the NSP3/4/6 proteins,crucial for regulating double-membrane vesicle(DMV)formation.However,the functional consequences of these NSP3/4/6 mutations remain poorly understood.In this study,a systematic analysis was conducted to investigate the evolutionary patterns of NSP3/4/6 mutations and their impact on DMV formation.The findings revealed that the NSP4 T492I mutation,a prevalent mutation found in all Delta and Omicron sub-lineages,notably enhances DMV formation.Mechanistically,the NSP4 T492I mutation enhances its homodimerization,leading to an increase in the size of puncta induced by NSP3/4,and also augments endoplasmic reticulum(ER)membrane curvature,resulting in a higher DMV density per fluorescent puncta.This study underscores the significance of the NSP4 T492I mutation in modulating DMV formation,with potential implications for the transmission dynamics of SARS-CoV-2.It contributes valuable insights into how these mutations impact viral replication and pathogenesis.
