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.
Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia, 23507, USA.
L K
LK
Hanson
B L
BL
Dalton
Z
Z
Karabekian
H E
HE
Farrell
W D
WD
Rawlinson
R M
RM
Stenberg
A E
AE
Campbell
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