An SH3 binding motif within the nucleocapsid protein of porcine reproductive and respiratory syndrome virus interacts with the host cellular signaling proteins STAMI, TXK, Fyn, Hck, and cortactin.

Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) causes an economically important global swine disease, and has a complicated virus-host immunomodulation that often leads to a weak Th2 immune response and viral persistence. In this study, we identified a Src homology 3 (SH3) binding motif, PxxPxxP, that is conserved within the N protein of PRRSV strains. Subsequently, we identified five host cellular proteins [signal transducing adaptor molecule (STAM)I, TXK tyrosine kinase (TXK), protein tyrosine kinase fyn (Fyn), hematopoietic cell kinase (Hck), and cortactin] that interact with this SH3 motif. We demonstrated that binding of SH3 proteins with PRRSV N protein depends on at least one intact PxxP motif as disruption of P53 within the motif significantly reduced interaction of each of the 5 proteins. The first PxxP motif appears to be more important for STAMI-N protein interactions whereas the second PxxP motif was more important for Hck interaction. Both STAMI and Hck interactions with PRRSV N protein required an unhindered C-terminal domain as the interaction was only observed with STAMI and Hck proteins with N-terminal but not C-terminal fluorescent tags. We showed that the P56 residue within the SH3 motif is critical for virus lifecycle as mutation resulted in a loss of virus infectivity, however the P50 and P53 mutations did not abolish virus infectivity suggesting that these highly conserved proline residues within the SH3 motif may provide a selective growth advantage through interactions with the host rather than a vital functional element. These results have important implications in understanding PRRSV-host interactions.

• Authors: Scott P Kenney, Xiang-Jin Meng
• Journal: Virus research (Virus Res) Vol. 204 Pg. 31-9 (Jun 02 2015) ISSN: 1872-7492 [Electronic] Netherlands
• PMID: 25882913 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical References

• Adaptor Proteins, Signal Transducing
• Cortactin
• Nucleocapsid Proteins
• Tec protein-tyrosine kinase
• Protein-Tyrosine Kinases
• Proto-Oncogene Proteins c-hck

Topics

• Adaptor Proteins, Signal Transducing (genetics, metabolism)
• Amino Acid Sequence
• Animals
• Cell Line
• Cortactin (genetics, metabolism)
• Cricetinae
• Genes, Reporter
• Haplorhini
• Humans
• Molecular Sequence Data
• Nucleocapsid Proteins (genetics, metabolism)
• Porcine Reproductive and Respiratory Syndrome (virology)
• Porcine respiratory and reproductive syndrome virus (genetics, metabolism)
• Protein Binding
• Protein-Tyrosine Kinases (genetics, metabolism)
• Proto-Oncogene Proteins c-hck (genetics, metabolism)
• Sequence Alignment
• Swine
• src Homology Domains