Interaction of the porcine reproductive and respiratory syndrome virus nucleocapsid protein with the inhibitor of MyoD family-a domain-containing protein.
Porcine reproductive and respiratory syndrome (PRRS) virus is an RNA virus that replicates in the cytoplasm, but the viral nucleocapsid (N) protein localizes specifically in the nucleus and nucleolus of virus-infected cells. Nuclear localization of N is non-essential for PRRSV replication in cultured cells but has been shown to modulate the pathogenesis of virus in pigs, suggesting that N plays an accessory role in the nucleus during infection. We identified by yeast two-hybrid screening the inhibitor of MyoD family-a (I-mfa) domain-containing protein (HIC) as a cellular partner for PRRS virus (PRRSV) N protein. This protein is a homolog of human HIC, a recently identified cellular transcription factor. The specific interaction of PRRSV N with HIC was confirmed in cells by mammalian two-hybrid assay and co-immunoprecipitation and in vitro by GST pull-down assay. HIC is a zinc-binding protein and confocal microscopy demonstrated co-localization of N with the HIC-p40 isomer in the nucleus and nucleolus, and in the cytoplasm with HIC-p32, which is the N-terminal truncation of HIC-p40. The porcine homolog of HIC is universally expressed in pig tissues including alveolar macrophages. The interaction of viral capsid with the cellular transcription factor implicates a possible regulation of host cell gene expression by the N protein during PRRSV infection.
Song
Cheng
C
Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Lu
Ray
R
Bienzle
Dorothee
D
Liu
Hsiao-Ching
HC
Yoo
Dongwan
D
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D017570:MyoD Protein / Q000037:antagonists & inhibitors*; D019590:Nucleocapsid Proteins / Q000378:metabolism*; D019316:Porcine respiratory and reproductive syndrome virus / Q000378:metabolism*; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine; D014764:Viral Proteins / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism
D017931:DNA Primers; D017570:MyoD Protein; D019590:Nucleocapsid Proteins; D014764:Viral Proteins; D015032:Zinc