title: Negatively charged residues in the endodomain are critical for specific assembly of spike protein into murine coronavirus.
abstract: Coronavirus spike (S) protein assembles into virions via its carboxy-terminus, which is composed of a transmembrane domain and an endodomain. Here, the carboxy-terminal charge-rich motif in the endodomain was verified to be critical for the specificity of S assembly into mouse hepatitis virus (MHV). Recombinant MHVs exhibited a range of abilities to accommodate the homologous S endodomains from the betacoronaviruses bovine coronavirus and human SARS-associated coronavirus, the alphacoronavirus porcine transmissible gastroenteritis virus (TGEV), and the gammacoronavirus avian infectious bronchitis virus respectively. Interestingly, in TGEV endodomain chimeras the reverting mutations resulted in stronger S incorporation into virions, and a net gain of negatively charged residues in the charge-rich motif accounted for the improvement. Additionally, MHV S assembly could also be rescued by the acidic carboxy-terminal domain of the nucleocapsid protein. These results indicate an important role for negatively charged endodomain residues in the incorporation of MHV S protein into assembled virions.
authors.affiliation: Department of Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Yao
authors.forename: Paul S
authors.initials: PS
authors.lastname: Masters
authors.forename: Rong
authors.initials: R
authors.lastname: Ye
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002460:Cell Line; D017938:Coronavirus, Bovine / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D006517:Murine hepatitis virus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D017434:Protein Structure, Tertiary / Q000235:genetics; D045473:Severe acute respiratory syndrome-related coronavirus; D064370:Spike Glycoprotein, Coronavirus; D005760:Transmissible gastroenteritis virus / Q000235:genetics / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019065:Virus Assembly
chemical_list: D008562:Membrane Glycoproteins; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus