Identification and characterization of a Marek's disease virus gene homologous to glycoprotein L of herpes simplex virus.
We have identified three Marek's disease virus (MDV) open reading frames (ORFs) within the BamHI D fragment of MDV genome. The predicted polypeptides are homologous to UL1 (glycoprotein L, gL), UL2 (uracil-DNA glycosylase), and UL3 (nuclear localizing phosphoprotein) of herpes simplex virus type 1 (HSV-1). Comparison of the deduced amino acid sequences of these three ORFs with HSV-1 counterparts revealed overall identities of 18, 43, and 49%, respectively. In spite of the low overall amino acid identity with HSV-1 gL, the first open reading frame was identified as a gL homolog of HSV-1 based not only on the gene arrangement but also on a limited amino acid conservation among gL homologs of alpha-herpesviruses. To characterize the expression of the MDV gL gene, an antiserum to a hydrophilic region of the gene expressed in a bacterial expression vector was produced. Immunoprecipitation with this antiserum revealed a 25,000-Da polypeptide in MDV-infected cells. Furthermore, the 25,000-Da polypeptide migrated as a 18,000-Da polypeptide following PNGase F treatment. This result is consistent with the predicted molecular weight of MDV gL, considering the two potential N-glycosylation sites and the predicted N-terminal signal sequence. A recombinant fowlpox virus expressing the MDV gL gene was generated to characterize this glycoprotein. Unlike gL in MDV-infected cells, gL expressed by recFPV-gL was highly sensitive to Endo H, indicating that it was probably retained in the endoplasmic reticulum and was not properly processed to a mature form. Therefore, similar to HSV-1 coexpression and complex formation of MDV gL and gH may be required for proper processing and transport of gL to the cell surface.
Yoshida
S
S
USDA-Agricultural Research Service, Avian Disease and Oncology Laboratory, East Lansing Michigan 48823.
Lee
L F
LF
Yanagida
N
N
Nazerian
K
K
D000595:Amino Acid Sequence; D000914:Antibodies, Viral; D001483:Base Sequence; D002240:Carbohydrate Sequence; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005587:Fowlpox virus / Q000235:genetics; D005814:Genes, Viral / Q000235:genetics*; D016679:Genome, Viral; D006031:Glycosylation; D008381:Herpesvirus 2, Gallid / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000276:immunology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D018139:Simplexvirus / Q000235:genetics; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D015678:Viral Structural Proteins / Q000235:genetics*
D000914:Antibodies, Viral; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins; D015678:Viral Structural Proteins; C077407:glycoprotein L, Human herpesvirus 1; C089459:glycoprotein L, Marek's disease virus