The capsid protein of infectious bursal disease virus contains a functional alpha 4 beta 1 integrin ligand motif.
Infectious bursal disease virus (IBDV), a member of the dsRNA Birnaviridae family, is an important immunosuppressive avian pathogen. We have identified a strictly conserved amino acid triplet matching the consensus sequence used by fibronectin to bind the alpha 4 beta 1 integrin within the protruding domain of the IBDV capsid polypeptide. We show that a single point mutation on this triplet abolishes the cell-binding activity of IBDV-derived subviral particles (SVP), and abrogates the recovering of infectious IBDV by reverse genetics without affecting the overall SVP architecture. Additionally, we demonstrate that the presence of the alpha 4 beta 1 heterodimer is a critical determinant for the susceptibility of murine BALB/c 3T3 cells to IBDV binding and infectivity. Our data suggests that the IBDV might also use the alpha 4 beta 1 integrin as a specific binding receptor in avian cells.
Delgui
Laura
L
Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología-CSIC, Cantoblanco, Calle Darwin no. 3,28049 Madrid, Spain.
Oña
Ana
A
Gutiérrez
Sylvia
S
Luque
Daniel
D
Navarro
Aitor
A
Castón
José R
JR
Rodríguez
José F
JF
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D041702:BALB 3T3 Cells; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D016384:Consensus Sequence; D007243:Infectious bursal disease virus / Q000235:genetics* / Q000378:metabolism; D039041:Integrin alpha4beta1 / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D017354:Point Mutation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012367:RNA, Viral / Q000235:genetics; D011991:Receptors, Virus / Q000378:metabolism; D016415:Sequence Alignment; D015678:Viral Structural Proteins / Q000235:genetics* / Q000378:metabolism
D036022:Capsid Proteins; D039041:Integrin alpha4beta1; D008024:Ligands; D012367:RNA, Viral; D011991:Receptors, Virus; C082513:VP2 protein, infectious bursal disease virus; D015678:Viral Structural Proteins