The human cytomegalovirus US3 immediate-early protein lacking the putative transmembrane domain regulates gene expression
- PMID: 8392711
- PMCID: PMC309686
- DOI: 10.1093/nar/21.12.2931
The human cytomegalovirus US3 immediate-early protein lacking the putative transmembrane domain regulates gene expression
Abstract
Through alternative transcript splicing, the human cytomegalovirus (HCMV) US3 immediate-early (IE) locus encodes multiple products including potential membrane-bound glycoproteins. To characterize the US3 products and determine which encode regulatory activity, individual cDNAs were cloned and expressed. Three transcript species were confirmed through the isolation of cDNAs; an unspliced transcript, a transcript spliced once from exon 3 to exon 5 and a transcript spliced both at exon 1 to exon 3 and at exon 3 to exon 5. The predicted signal sequences and N-linked glycosylation sites in the US3 products were confirmed using expression in reticulocyte lysates containing microsomal membranes. Regulatory activity of the individual US3 products was demonstrated using transient transfection assays. The unspliced cDNA and the cDNA containing the exon 3 to exon 5 splice, encoded products which increased expression of the human heat shock protein 70 (hsp70) promoter, while the product of the doubly-spliced US3 cDNA did not. Transactivation was synergistically increased by coexpression with the HCMV UL37 protein. We conclude that the first 132 amino acids common to the unspliced and the singly-spliced US3 gene products are sufficient for hsp70 transactivation; while the amino-terminal 28 amino acids, encoded by the doubly-spliced US3 cDNA, are not. These results demonstrate that a US3 IE protein lacking the putative transmembrane domain has regulatory activity.
Similar articles
-
Human cytomegalovirus US3 and UL36-38 immediate-early proteins regulate gene expression.J Virol. 1992 Jan;66(1):95-105. doi: 10.1128/JVI.66.1.95-105.1992. J Virol. 1992. PMID: 1370097 Free PMC article.
-
Human cytomegalovirus UL36-38 and US3 immediate-early genes: temporally regulated expression of nuclear, cytoplasmic, and polysome-associated transcripts during infection.J Virol. 1991 Dec;65(12):6724-34. doi: 10.1128/JVI.65.12.6724-6734.1991. J Virol. 1991. PMID: 1658371 Free PMC article.
-
Human cytomegalovirus UL37 immediate early target minigene RNAs are accurately spliced and polyadenylated.J Gen Virol. 2003 Jan;84(Pt 1):29-39. doi: 10.1099/vir.0.18700-0. J Gen Virol. 2003. PMID: 12533698
-
Functional roles of immediate early proteins encoded by the human cytomegalovirus UL36-38, UL115-119, TRS1/IRS1 and US3 loci.Intervirology. 1996;39(5-6):350-60. doi: 10.1159/000150506. Intervirology. 1996. PMID: 9130045 Review.
-
Activation and regulation of human cytomegalovirus early genes.Intervirology. 1996;39(5-6):361-77. doi: 10.1159/000150507. Intervirology. 1996. PMID: 9130046 Review.
Cited by
-
Characterization of a cluster of late genes of guinea pig cytomegalovirus.Virus Genes. 2001 Dec;23(3):247-56. doi: 10.1023/a:1012536804190. Virus Genes. 2001. PMID: 11778692
-
Inhibition of human cytomegalovirus immediate-early gene expression by cyclin A2-dependent kinase activity.J Virol. 2012 Sep;86(17):9369-83. doi: 10.1128/JVI.07181-11. Epub 2012 Jun 20. J Virol. 2012. PMID: 22718829 Free PMC article.
-
Identification of a novel transcriptional repressor encoded by human cytomegalovirus.J Virol. 2001 Jul;75(13):6062-9. doi: 10.1128/JVI.75.13.6062-6069.2001. J Virol. 2001. PMID: 11390608 Free PMC article.
-
Multiple independent loci within the human cytomegalovirus unique short region down-regulate expression of major histocompatibility complex class I heavy chains.J Virol. 1995 Aug;69(8):4830-41. doi: 10.1128/JVI.69.8.4830-4841.1995. J Virol. 1995. PMID: 7609050 Free PMC article.
-
Regulation of a human cytomegalovirus immediate-early gene (US3) by a silencer-enhancer combination.J Virol. 1996 Jan;70(1):91-100. doi: 10.1128/JVI.70.1.91-100.1996. J Virol. 1996. PMID: 8523597 Free PMC article.
References
MeSH terms
Substances
Associated data
- Actions
LinkOut - more resources
Full Text Sources