The coronavirus life cycle is depicted in a figure from Fung and Liu (2019). See below for a brief description.
The virus particle attaches to receptors on the cell surface (mostly ACE2 in the case of SARS-CoV-2). It is taken into the cell by endocytosis and then the viral membrane fuses with the host membrane releasing the viral RNA. The viral RNA is translated to produce the 1a and 1ab polyproteins, which are cleaved to produce 16 nonstructural proteins (nsps). Most of the nsps assemble to from the replication-transcription complex (RTC). [see Structure and expression of the SARS-CoV-2 (coronavirus) genome]
RTC transcribes the original (+) strand creating (-) strands that are subsequently copied to make more viral (+) strands. RTC also produces a cluster of nine (-) strand subgenomic RNAs (sgRNAs) that are transcribed to make (+) sgRNAs that serve as mRNAs for the production of the structural proteins. N protein (nucleocapsid) binds to the viral (+) strand RNAs to help form new viral particles. The other structural proteins are synthesized in the endoplasmic reticulum (ER) where they assemble to form the protein-membrane virus particle that engulfs the viral RNA.
New virus particles are released when the vesicles fuse with the plasma membrane.
The entire life cycle takes about 10-16 hours and about 100 new virus particles are released before the cell commits suicide by apoptosis.
The virus particle attaches to receptors on the cell surface (mostly ACE2 in the case of SARS-CoV-2). It is taken into the cell by endocytosis and then the viral membrane fuses with the host membrane releasing the viral RNA. The viral RNA is translated to produce the 1a and 1ab polyproteins, which are cleaved to produce 16 nonstructural proteins (nsps). Most of the nsps assemble to from the replication-transcription complex (RTC). [see Structure and expression of the SARS-CoV-2 (coronavirus) genome]
RTC transcribes the original (+) strand creating (-) strands that are subsequently copied to make more viral (+) strands. RTC also produces a cluster of nine (-) strand subgenomic RNAs (sgRNAs) that are transcribed to make (+) sgRNAs that serve as mRNAs for the production of the structural proteins. N protein (nucleocapsid) binds to the viral (+) strand RNAs to help form new viral particles. The other structural proteins are synthesized in the endoplasmic reticulum (ER) where they assemble to form the protein-membrane virus particle that engulfs the viral RNA.
New virus particles are released when the vesicles fuse with the plasma membrane.
The entire life cycle takes about 10-16 hours and about 100 new virus particles are released before the cell commits suicide by apoptosis.
Fung, T.S. and Liu, D.X. (2019) Human coronavirus: host-pathogen interaction. Annual review of microbiology 73:529-557. [doi: 10.1146/annurev-micro-020518-115759]
