Articles written in Journal of Biosciences
Volume 32 Issue 6 September 2007 pp 1111-1118 Articles
Human cytomegalovirus (HCMV), a ubiquitous human pathogen, is the leading cause of birth defects in newborns. A region (referred to as UL/b′) present in the Toledo strain of HCMV and low-passage clinical isolates) contains 22 additional genes, which are absent in the highly passaged laboratory strain AD169. One of these genes, UL145 open reading frame (ORF), is located between the highly variable genes UL144 and UL146. To assess the structure of the UL145 gene, the UL145 ORF was amplified by PCR and sequenced from 16 low-passage clinical isolates and 15 non-passage strains from suspected congenitally infected infants. Nine UL145 sequences previously published in the GenBank were used for sequence comparison. The identities of the gene and the similarities of its putative protein among all strains were 95.9–100% and 96.6–100%, respectively. The post-translational modification motifs of the UL145 putative protein in clinical strains were conserved, comprising the protein kinase C phosphorylation motif (PKC) and casein kinase II phosphorylation site (CK-II). We conclude that the structure of the UL145 gene and its putative protein are relatively conserved among clinical strains, irrespective of whether the strains come from patients with different manifestations, from different areas of the world, or were passaged or not in human embryonic lung fibroblast (HELF) cells.
Volume 35 Issue 3 September 2010 pp 365-370 Articles
Human cytomegalovirus (HCMV) mRNA was obtained from human embryonic lung fibroblast cells infected by HCMV clinical strains from urine samples of infants at different kinetic periods. The cDNA of UL131A-128 mRNAs was amplified using reverse transcription-polymerase chain reaction (RT-PCR) and analysed by sequencing. Mean while, clones containing UL131A-128 transcripts in an HCMV cDNA library of a clinical strain were selected and sequenced. It was demonstrated that UL131A-128 mRNA was expressed with immediately early, early and late kinetics. Sequences obtained by RT-PCR showed that the UL131A gene consisted of two exons and the coding region of the UL130 gene was not interrupted by any intron in the region as reported earlier. However, the transcript of the UL128 gene showed two patterns: one pattern consisted of three exons as reported earlier; the other contained the three exons and also the first intron. Moreover, the above characteristics of UL131A-128 spliced transcripts were confirmed by the sequences of clones selected from the HCMV cDNA library. Our results demonstrated that the UL131A, UL130 and UL128 genes were transcribed with the 3′-coterminal, although the initiation points of their mRNA may be different. The variation in the transcripts found in our study indicated the complex nature of transcription of UL131A-128 genes in clinical strains of HCMV.
Volume 38 Issue 1 March 2013 pp 35-44 Articles
Transcription of human cytomegalovirus UL/b′ region has been studied extensively for some genes. In this study, transcripts of the UL140 and UL141, two of the UL/b′ genes, were identified in late RNAs of three HCMV isolates using Northern blot hybridization, cDNA library screening and RACE-PCR. At least three transcripts with length of 2800, 2400 and 1700 nt, as well as a group of transcripts of about 1000–1300 nt, were found in this gene region with an accordant 3′ ends. Among the transcripts, two initiated upstream of the start code of the UL140 gene and contained the UL140 and UL141 open reading frame (ORF), one initiated in the middle of the UL140 gene, and could encode short ORFs upstream of the UL141 ORF. A group of transcripts initiated upstream or downstream of the start code of the UL141 gene, and could encode `nested’ ORFs, including the UL141 ORF. These `nested’ ORFs possess different initiation sites but the same termination site as that of the UL141 ORF.
Volume 38 Issue 3 September 2013 pp 479-485 Articles
MicroRNAs (miRNAs) are small RNAs, 19–23 nucleotides in length, which regulate a variety of cellular processes. Human cytomegalovirus (HCMV) encodes only one intronic miRNA: human cytomegalovirus microRNA UL36 (hcmv-miR-UL36). In this study, we found that over-expression of hcmv-miR-UL36 resulted in a more than threefold increase in HCMV DNA synthesis at 24 h post infection. Fifteen putative targets of hcmv-miR-UL36 were identified using hybrid PCR, one being the HCMV UL138 gene that has previously been identified as a novel latency-associated determinant of HCMV infection. Down-regulation of UL138 expression by hcmv-miR-UL36 was validated using luciferase reporter assays and Western blot analysis in HEK293 cells. In the presence of hcmv-miR-UL36, we observed a 74.6% decrease in luciferase activity and a 46.2% decrease in HCMV UL138 protein expression. Our results indicate that hcmv-miR-UL36 may be a viral miRNA contributing to HCMV replication.
Volume 41 Issue 2 June 2016 pp 173-182 Article
The interplay between the host and Human cytomegalovirus (HCMV) plays a pivotal role in the outcome of an infection. HCMV growth in endothelial and epithelial cells requires expression of viral proteins UL128, UL130, and UL131 proteins (UL128-131), of which UL130 is the largest gene and the only one that is not interrupted by introns. Mutation of the C terminus of the UL130 protein causes reduced tropism of endothelial cells (EC). However, very few host factors have been identified that interact with the UL130 protein. In this study, HCMV UL130 protein was shown to directly interact with the human protein Snapin in human embryonic kidney HEK293 cells by Yeast two-hybrid screening, in vitro glutathione S-transferase (GST) pull-down, and co-immunoprecipitation. Additionally, heterologous expression of protein UL130 revealed co-localization with Snapin in the cell membrane and cytoplasm of HEK293 cells using fluorescence confocal microscopy. Furthermore, decreasing the level of Snapin via specific small interfering RNAs decreased the number of viral DNA copies and titer in HCMV-infected U373-S cells. Taken together, these results suggest that Snapin, the pUL130 interacting protein, has a role in modulating HCMV DNA synthesis.
Volume 41 Issue 2 June 2016 pp 183-192 Article
Human cytomegalovirus-encoded miR-US4-1 promotes cell apoptosis and benefits discharge of infectious virus particles via down-regulation of glutaminyl-tRNA synthetase, QARS in HCMV-infected HELF cells