Identification and characterization of a spliced C-type lectin-like gene encoded by rat cytomegalovirus.
The English isolate of rat cytomegalovirus (RCMV) encodes a 20-kDa protein with a C-type lectin-like domain that is expressed in the delayed-early and late phases of the viral replication cycle. Genomic sequence analysis of the restriction fragment KpnR of RCMV revealed significant homology to several C-type lectin-containing molecules implicated in natural killer (NK) and T-cell interactions, as well as genes from four poxviruses and African swine fever virus. The gene is spliced into five exons and shows a splicing pattern with exon boundaries similar to those observed in the human differentiation antigen CD69. The cap site of the gene was mapped by RNase protection, 5' rapid amplification of cDNA ends, and primer extension experiments. This analysis demonstrated that the core promoter of the RCMV lectin-like gene contains a GATA rather than a TATA box. Splicing patterns were confirmed with isolates from an infected-cell cDNA library. A unique aspect of the protein is that its translation is not initiated by the canonical methionine but rather by alanine. To study its role in virus replication and pathogenesis, a recombinant virus was constructed in which the gene is interrupted. Replication in tissue culture was similar to that of wild-type virus.
Voigt
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S
BMT Program, Departments of Medicine and Microbiology & Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
Sandford
G R
GR
Ding
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L
Burns
W H
WH
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000235:genetics; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics; D001483:Base Sequence; D002460:Cell Line; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D005091:Exons / Q000235:genetics; D006801:Humans; D037102:Lectins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D037181:Lectins, C-Type; D008969:Molecular Sequence Data; D018146:Muromegalovirus / Q000235:genetics* / Q000502:physiology; D012326:RNA Splicing / Q000235:genetics*; D051381:Rats; D015183:Restriction Mapping; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014764:Viral Proteins; D014779:Virus Replication; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D015252:Deoxyribonucleases, Type II Site-Specific; D037102:Lectins; D037181:Lectins, C-Type; D014764:Viral Proteins; D000099192:CD69 Antigens; C418632:C-type lectin, Rat Cytomegalovirus; C029312:GGTACC-specific type II deoxyribonucleases