Cloning and epitope mapping of a functional partial fusion receptor for human cytomegalovirus gH.
A cDNA clone encoding a partial putative human cytomegalovirus (HCMV) gH fusion receptor (CMVFR) was previously identified. In this report, the cDNA sequence of CMVFR was determined and the role of this CMVFR in HCMV/cell fusion was confirmed by rendering fusion-incompetent MOLT-4 cells susceptible to fusion following transfection with receptor cDNA. Blocking experiments using recombinant gH or either of two MAbs (against recombinant gH or purified viral gH:gL) provided additional evidence for the role of gH binding to this protein in virus fusion. An HCMV-binding domain of 12 aa in the middle hydrophilic region of CMVFR was identified by fusion blocking studies using synthetic receptor peptides. The 1368 bp cDNA of CMVFR contained a predicted ORF of 345 aa with two potential membrane-spanning domains and several possible nuclear localization signals. A search of sequence databases indicated that CMVFR is a novel protein. Further characterization of this cell membrane protein that confers susceptibility to fusion with the viral envelope should provide important information about the mechanism by which HCMV infects cells.
Baldwin
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Molecular and Cell Biology Program, University of Maryland School of Medicine, Baltimore, MD 21201, USA. bbald001@umaryland.edu
Zhang
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Keay
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D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D003001:Cloning, Molecular; D003587:Cytomegalovirus / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000472:pathogenicity*; D018076:DNA, Complementary; D018604:Epitope Mapping; D006801:Humans; D008561:Membrane Fusion; D008969:Molecular Sequence Data; D011991:Receptors, Virus / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014162:Transfection; D014407:Tumor Cells, Cultured; D014759:Viral Envelope Proteins / Q000378:metabolism*; D010948:Viral Plaque Assay
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D011991:Receptors, Virus; D014759:Viral Envelope Proteins; C071440:glycoprotein H, Cytomegalovirus; C499358:glycoprotein H, Human cytomegalovirus