Transcriptional analysis of the murine cytomegalovirus HindIII-I region: identification of a novel immediate-early gene region.
Cytomegaloviruses likely encode numerous gene products involved in regulating virus-host cell interactions and pathogenesis. We previously identified a region of murine cytomegalovirus (MCMV) within HindIII-J and -I that regulates pathogenesis of the virus [open reading frames (ORFs) M139-M141] or is likely required for MCMV replication (ORFs m142 and m143). As a prerequisite for further studies on the structure and function of this gene region, we mapped the transcripts encoded within MCMV HindIII-I. Probes for ORFs M140 and M141 hybridized to 5.4- and 7.0-kb RNA, respectively, which were transcribed with early kinetics and were 3' coterminal with HindIII-J ORF M139. Probes representing ORFs m142, m143, or m144 hybridized to 3' coterminal transcripts of 1.8, 3.8, and 5.1 kb, respectively. ORFs m142 and m143 were transcribed with immediate-early kinetics but were most abundantly expressed at early times. Probes for the rightmost end of HindIII-I hybridized to a 5. 1-kb early/late RNA corresponding to m144 and to a 1.8-kb early RNA transcribed from m145. All of the major transcripts were polyadenylated and therefore are likely coding. Additional minor transcripts of intermediate sizes were also detected. ORFs M139-m143 showed homology to the betaherpesvirus-specific HCMV US22 gene family. Because deletion of these viral genes results in attenuated or helper-dependent phenotypes, this conserved region of US22 family genes may have a role in virus replication as well as in the pathogenesis of betaherpesviruses in their natural hosts.
Hanson
L K
LK
Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia, 23507, USA.
Dalton
B L
BL
Karabekian
Z
Z
Farrell
H E
HE
Rawlinson
W D
WD
Stenberg
R M
RM
Campbell
A E
AE
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D015247:Deoxyribonuclease HindIII / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D017781:Genes, Immediate-Early; D008264:Macrophages / Q000821:virology; D051379:Mice; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D014158:Transcription, Genetic
D015247:Deoxyribonuclease HindIII