TY - JOUR
T1 - Processing of the herpes simplex virus assembly protein ICP35 near its carboxy terminal end requires the product of the whole of the UL26 reading frame
AU - Preston, Valerie G.
AU - Rixon, Frazer J.
AU - McDougall, Iris M.
AU - McGregor, Mark
AU - Al Kobaisi, Muhannad F.
N1 - Funding Information:
We thank Professorl. H. Subak-Sharpe for his support and encouragement. We are also grateful to P. Sheldrick for supplying the mutant fs2 and parental virus, A. Cross for the gift of monoclonal antibodies specific for ICP35, A. Owsianka for the preparation of the oligopeptide, and D. 1. McGeoch for helpful comments on the manuscript. M. F. Al-Kobaisi received a scholarship from the Iraqi Scientific Research Council.
PY - 1992/1
Y1 - 1992/1
N2 - The herpes simplex virus (HSV) type 1 assembly protein ICP35 consists of a family of polypeptides, ranging in molecular weight from about 45,000-39,000. The lower molecular weight forms of ICP35 are derived from the higher molecular weight species by slow post-translational modification. The reading frame of gene UL26 and the region within this gene which exhibited homology to the cytomegalovirus assembly protein, the analogous protein to ICP35, were expressed separately under immediate-early (IE) gene regulation in a HSV vector containing a temperature-sensitive mutation in the major transcriptional regulator Vmwt 75. Monoclonal antibody specific for ICP35 immunoprecipitated several polypeptides with molecular weights around 75,000 from extracts of cells infected with a recombinant expressing the IE gene UL26 at the nonpermissive temperature (NPT). These results suggested that the UL26 gene specified a protein distinct from ICP35 but which had some antigenic sites in common with ICP35. In extracts of cells infected at the NPT with a recombinant expressing only the carboxy terminal half of UL26 coding sequences, the monoclonal antibody immunoprecipitated large amounts of the high molecular weight forms of ICP35. The lower molecular weight processed forms of ICP35, however, were not detectable. When cells were coinfected with both recombinants ICP35 was processed to its lower molecular weight forms. This processing step, which occurred near the carboxy terminus of ICP35, was not dependent on capsid formation. The work, together with previous information on the processing of the CMV assembly protein, suggests that UL26 product may be a protease.
AB - The herpes simplex virus (HSV) type 1 assembly protein ICP35 consists of a family of polypeptides, ranging in molecular weight from about 45,000-39,000. The lower molecular weight forms of ICP35 are derived from the higher molecular weight species by slow post-translational modification. The reading frame of gene UL26 and the region within this gene which exhibited homology to the cytomegalovirus assembly protein, the analogous protein to ICP35, were expressed separately under immediate-early (IE) gene regulation in a HSV vector containing a temperature-sensitive mutation in the major transcriptional regulator Vmwt 75. Monoclonal antibody specific for ICP35 immunoprecipitated several polypeptides with molecular weights around 75,000 from extracts of cells infected with a recombinant expressing the IE gene UL26 at the nonpermissive temperature (NPT). These results suggested that the UL26 gene specified a protein distinct from ICP35 but which had some antigenic sites in common with ICP35. In extracts of cells infected at the NPT with a recombinant expressing only the carboxy terminal half of UL26 coding sequences, the monoclonal antibody immunoprecipitated large amounts of the high molecular weight forms of ICP35. The lower molecular weight processed forms of ICP35, however, were not detectable. When cells were coinfected with both recombinants ICP35 was processed to its lower molecular weight forms. This processing step, which occurred near the carboxy terminus of ICP35, was not dependent on capsid formation. The work, together with previous information on the processing of the CMV assembly protein, suggests that UL26 product may be a protease.
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U2 - 10.1016/0042-6822(92)90063-U
DO - 10.1016/0042-6822(92)90063-U
M3 - Article
C2 - 1309284
AN - SCOPUS:0026516706
SN - 0042-6822
VL - 186
SP - 87
EP - 98
JO - Virology
JF - Virology
IS - 1
ER -