Interactions between coronavirus nucleocapsid protein and viral RNAs: implications for viral transcription.
The interaction of the mouse hepatitis virus (MHV) nucleocapsid protein (N) and viral RNA was examined. Monoclonal antibody specific for N protein coimmunoprecipitated MHV genomic RNA as well as all six MHV subgenomic mRNAs found in MHV-infected cells. In contrast, monoclonal antibodies to the MHV E2 or E1 envelope glycoproteins, an anti-I-A monoclonal antibody, and serum samples from lupus patients did not immunoprecipitate the MHV mRNAs. Moreover, the anti-N monoclonal antibody did not coimmunoprecipitate vesicular stomatitis virus RNA or host cell RNA under conditions which immunoprecipitated all MHV RNAs. These data suggest a specific interaction between the N protein and the virus-specific mRNAs. Both the membrane-bound and cytosolic small MHV leader-specific RNAs of greater than 65 nucleotides long were immunoprecipitated only by anti-N monoclonal antibody. These data suggest that an N binding site is present within the leader RNA sequences at a site at least 65 nucleotides from the 5' end of genomic RNA and all six subgenomic mRNAs. The larger leader-containing RNAs originating from mRNA 1 and mRNA 6, as well as the MHV negative-stranded RNA, were also immunoprecipitated by the anti-N monoclonal antibody. These data indicate that the MHV N protein is associated with MHV-specific RNAs and RNA intermediates and may play an important functional role during MHV transcription and replication.
Baric
R S
RS
Department of Parasitology and Laboratory Practice, University of North Carolina School of Public Health, Chapel Hill 27514.
Nelson
G W
GW
Fleming
J O
JO
Deans
R J
RJ
Keck
J G
JG
Casteel
N
N
Stohlman
S A
SA
D000911:Antibodies, Monoclonal; D001483:Base Sequence; D001665:Binding Sites; D002213:Capsid / Q000378:metabolism* / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology; D006517:Murine hepatitis virus / Q000235:genetics* / Q000378:metabolism; D011233:Precipitin Tests; D012367:RNA, Viral / Q000096:biosynthesis / Q000378:metabolism* / Q000502:physiology; D016601:RNA-Binding Proteins; D014158:Transcription, Genetic; D014721:Vesicular stomatitis Indiana virus / Q000378:metabolism; D014758:Viral Core Proteins / Q000378:metabolism* / Q000502:physiology; D014776:Virus Cultivation
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D014758:Viral Core Proteins