Genetic evidence for a structural interaction between the carboxy termini of the membrane and nucleocapsid proteins of mouse hepatitis virus.
The coronavirus membrane (M) protein is the most abundant virion protein and the key component in viral assembly and morphogenesis. The M protein of mouse hepatitis virus (MHV) is an integral membrane protein with a short ectodomain, three transmembrane segments, and a large carboxy-terminal endodomain facing the interior of the viral envelope. The carboxy terminus of MHV M has previously been shown to be extremely sensitive to mutation, both in a virus-like particle expression system and in the intact virion. We have constructed a mutant, M(Delta)2, containing a two-amino-acid truncation of the M protein that was previously thought to be lethal. This mutant was isolated by means of targeted RNA recombination with a powerful host range-based selection allowed by the interspecies chimeric virus fMHV (MHV containing the ectodomain of the feline infectious peritonitis virus S protein). Analysis of multiple second-site revertants of the M(Delta)2 mutant has revealed changes in regions of both the M protein and the nucleocapsid (N) protein that can compensate for the loss of the last two residues of the M protein. Our data thus provide the first genetic evidence for a structural interaction between the carboxy termini of the M and N proteins of MHV. In addition, this work demonstrates the efficacy of targeted recombination with fMHV for the systematic genetic analysis of coronavirus structural protein interactions.
Kuo
Lili
L
Wadsworth Center, New York State Department of Health, Albany, New York 12201-2002, USA.
Masters
Paul S
PS
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D000086862:Coronavirus M Proteins; D008562:Membrane Glycoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D006517:Murine hepatitis virus / Q000378:metabolism*; D009154:Mutation; D019251:Nucleocapsid / Q000235:genetics* / Q000378:metabolism; D019590:Nucleocapsid Proteins; D011485:Protein Binding; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins / Q000235:genetics; D014763:Viral Matrix Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
D000086862:Coronavirus M Proteins; D008562:Membrane Glycoproteins; D019590:Nucleocapsid Proteins; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; D014763:Viral Matrix Proteins; C099600:nucleocapsid protein, Hepatitis virus; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus