L* protein of Theiler's murine encephalomyelitis virus is required for virus growth in a murine macrophage-like cell line.
We sought to confirm the importance of L* protein for growth of Theiler's murine encephalomyelitis virus (TMEV) in a macrophage-like cell line, J774-1. The protein is out of frame with the polyprotein and synthesized in DA but not GDVII subgroup strains of TMEV. A recombinant virus, DANCL*/GD, which substitutes the DA 5' noncoding and L* coding regions for the corresponding regions of GDVII and synthesizes L* protein, grew with little restriction in J774-1 cells. In contrast, another recombinant virus, DANCL*-1/GD, which has an ACG rather than an AUG as the starting codon of L* protein at nucleotide 1079, resulting in no synthesis of L* protein, did not grow well. No significant difference between the rates of adsorption to J774-1 cells of these viruses was observed. RNase protection assay demonstrated that DANCL*/GD viral RNA significantly increased, whereas only a minimal increase was observed for DANCL*-1/GD. The present study suggests that L* protein is required for virus growth in macrophages.
Obuchi
M
M
Departments of Microbiology, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan.
Yamamoto
J
J
Odagiri
T
T
Uddin
M N
MN
Iizuka
H
H
Ohara
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D007700:Kinetics; D008264:Macrophages / Q000821:virology*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D017945:Theilovirus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*
C096897:L(asterisk) protein, Theiler's encephalomyelitis virus; D008565:Membrane Proteins; D011994:Recombinant Proteins; D014764:Viral Proteins; D012260:Ribonucleases