Arch Virol (2004) 149: 495–506
Glycoprotein gpTRL10 of human cytomegalovirus
is dispensable for virus replication in human ﬁbroblasts
, G. Hahn
, and M. Mach
Institut f¨ur Klinische und Molekulare Virologie, Universit¨at Erlangen-N¨urnberg,
Max von Pettenkofer Institut f¨ur Virologie, Ludwig-Maximilians-Universit¨at
M¨unchen, M¨unchen, Germany
Received July 22, 2003; accepted September 5, 2003
Published online November 13, 2003
Summary. Human cytomegalovirus (HCMV) has a coding capacity for glycopro-
teins which by far exceeds that of other herpesviruses. Few of these proteins have
been characterized. Glycoprotein gpTRL10 represents a structural component of
HCMV. The protein has no homologous counterparts in other herpesviruses. We
have isolated bacterial artiﬁcial chromosomes (BACs) harboring the genome from
the low passage clinical isolate PAN and constructed a deletion mutant in reading
frame TRL10. Our results show that deletion of gpTRL10 has only minimal effects
on viral replication in human ﬁbroblasts.
The envelope glycoproteins of herpesviruses have multiple roles in the viral
replication cycle, including essential functions such as attachment, penetration,
cell-to-cell spread, envelopment and maturation of nascent viral particles .
To understand these processes, it is necessary to have detailed knowledge of
the structure and function of envelope glycoproteins. Envelope glycoproteins
can elicit a protective virus-neutralizing humoral immune response and thus
have been proposed as important components of subunit vaccines. In addition to
glycoproteins such as gB, gH, gL, gM, gN that are conserved between members of
the family Herpesviridae, herpesviruses also encode for a number of glycoproteins
that are expressed only by viruses in a single genus or individual members .
These “private” glycoproteins potentially serve important functions such as cell
tropism or pathogenicity. Two structural glycoproteins without homology to other
herpesviruses have been described for Human cytomegalovirus (HCMV): gO,
product of the open reading frame (orf) UL74 and gp48, the product of UL4 .