Interaction of Bombyx mori nucleopolyhedrovirus BRO-A and host cell protein laminin.
The Bombyx mori nucleopolyhedrovirus (BmNPV) contains five baculovirus repeated ORF ( bro) genes, all of which are expressed as delayed early genes. We have recently reported that BmNPV BRO proteins, specially BRO-A and BRO-C, contain a nucleic acid binding activity and are involved in nucleosome structures in nuclei of infected cells. To further understand the function of bro-a gene, we looked for factors interacting with BmNPV BRO-A using the yeast two-hybrid system. Fifteen clones obtained from a cDNA library of mock-infected cells and one from a library prepared at 2 h postinfection (p.i.) were found to comprise one distinct gene, which was identified as the Bombyx homolog (bLaminin) of Drosophila laminin beta1. A direct interaction between BRO-A and N-terminal region of bLaminin was demonstrated by in vitro pull-down experiments. Further pull-down assays using BmN cell extracts and anti-laminin antibodies also showed interaction of both proteins. In addition, two more clones were obtained from cDNA library of 12 h p.i. and were found to encode BRO-A itself, indicating that BRO-A forms an oligomer. Taken together, we propose that BRO-A may function as a laminin binding protein.
Kang
W K
WK
Laboratory of Molecular Entomology and Baculovirology, RIKEN, Wako, Japan. wkkang@postman.riken.go.jp
Imai
N
N
Suzuki
M
M
Iwanaga
M
M
Matsumoto
S
S
Zemskov
E A
EA
D024509:3' Flanking Region; D020413:3' Untranslated Regions; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000821:virology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D007797:Laminin / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D017924:Nucleopolyhedroviruses / Q000235:genetics / Q000378:metabolism*; D009698:Nucleoproteins / Q000378:metabolism; D016366:Open Reading Frames; D017386:Sequence Homology, Amino Acid
D020413:3' Untranslated Regions; D004268:DNA-Binding Proteins; D007797:Laminin; D009698:Nucleoproteins