Characterization of human cytomegalovirus UL145 and UL136 genes in low-passage clinical isolates from infected Chinese infants.

BACKGROUND: Human cytomegalovirus (HCMV) is a leading cause of morbidity and mortality in immunocompromised individuals. The unique long b' (ULB') region of HCMV contains at least 19 open reading frames (ORFs); however, little is known about the function of UL145 and UL136. We characterized UL145 and UL136 in low-passage clinical isolates from Chinese infants. MATERIAL/METHODS: The clinical strains of HCMV were recovered from the urine from HCMV-infected infants. Human embryonic lung fibroblasts (HELFs) were infected with clinical isolates of HCMV, and the viral DNA and mRNA for UL145 and UL136 were analyzed by polymerase chain reaction (PCR) and sequencing techniques. We also predicted the structure and function of UL145 and UL136 proteins. RESULTS: Sixty-two Chinese infants infected with HCMV were recruited into this study and the clinical isolates were recovered from the urine. Two strains among the low-passage isolates, D2 and D3, were obtained. The UL145 and UL136 sequences were deposited with GenBank under accession numbers of DQ180367, DQ180381, DQ180377, and DQ180389. The mRNA expression of both UL145 and UL136 was confirmed by reverse transcription (RT-PCR) assays. UL145 was predicted to contain 1 protein kinase C phosphorylation site, 2 casein kinase II phosphorylation sites and a zinc finger structure. UL136 was predicted to contain a protein kinase C phosphorylation site, N-myristoylation site, cAMP- and cGMP-dependent protein kinase phosphorylation site and tyrosine kinase II phosphorylation site. Both UL145 and UL136 are highly conserved. CONCLUSIONS: UL145 may act as an intranuclear regulating factor by direct binding to DNA, while UL136 may be a membrane receptor involving signal transduction.

[Identification and expression of human cytomegalovirus UL148 mRNA of low-passage clinical isolates in Guangzhou].

OBJECTIVE: To research the structure of the unique gene UL148 of the human cytomegalovirus (HCMV) clinical strain in Guangzhou, analyze the relation between its structure polymorphism and HCMV congenital infection, investigate the function of its expression products, and try to reveal the pathogenic mechanism of the gene in HCMV infection in newborns. METHODS: Urine samples were collected from 10 newborns with HCMV infection and inoculated on human fetal lung cells. The viral DNA was isolated, and UL148 gene fragment was amplified and identified. After TA clone and gene sequencing, total RNA of virus was extracted and the mRNA expression of UL148 gene was identified by using RT-PCR. RESULTS: The UL148 gene complete sequence was determined. A specific 582 bp length DNA fragment was amplified by RT-PCR, which confirmed the expression of UL148 gene. CONCLUSIONS: UL148 gene exists in the low-passage clinical HCMV isolate from Guangzhou. It is confirmed that open reading frame of UL148 has genetic structure with mRNA expression.