Disease relevance of UL56

• These results demonstrate that the HSV-1 UL55 and UL56 genes are not critical for intraperitoneal virulence or establishment of latent infection [1].
• Experiments were undertaken to identify the product of open reading frame (orf) UL56 of human cytomegalovirus (HCMV), the putative homolog of infected cell protein (ICP) 18.5 of herpes simplex virus type 1 (HSV-1) that is thought to be involved in viral nucleocapsid maturation [2].
• Identification of the gene product encoded by ORF UL56 of the human cytomegalovirus genome [2].
• The UL56 protein was detected in the HSV-1 virions by immuno gold negative staining [3].
• This procedure allowed the expression of the viral UL56 gene fused to the maltose-binding protein (MBP) of Escherichia coli, and subsequent cleavage of the fusion protein with the specific protease factor Xa [4].

High impact information on UL56

• The UL56 gene product of herpes simplex virus (HSV) has been shown to play an important role in viral pathogenicity [5].
• Identification and characterization of the UL56 gene product of herpes simplex virus type 2 [5].
• Studies of their origins showed that the UL56 protein of HSV-2 is also translated from the upstream in-frame methionine codon that is not present in the HSV-1 genome [5].
• Moreover, the results of protease digestion assays and sucrose gradient fractionation strongly suggested that UL56 is a tail-anchored type II membrane protein associated with lipid rafts [5].
• Indirect immunofluorescence studies revealed that the UL56 protein localized to both the Golgi apparatus and cytoplasmic vesicles in HSV-2-infected and single UL56-expressing cells [5].

Biological context of UL56

• Sequence analysis revealed that the deletion removes a region to the right of IE2 comprising the 3' end of IE1, UL56 and the 3' part of UL55, stopping 555 bp downstream of the IE2 polyadenylation signal [6].
• The deleted region of the DNA sequences of the UL56 gene between NP 1122-1175 corresponds to NP 116 220-116 373 of the viral genome [7].
• The analysis revealed that the expression of the truncated UL56 protein (without hydrophobic domain 217-234 aa) was not sufficient for the maintenance of the virulent phenotype of HSV-1 strains [7].
• The promoter region of the UL56 gene of HSV-1 strain HFEM is a part of the deleted DNA sequences [8].
• The results of these experiments indicate that the restoration of the viral UL56 gene expression led to the restitution of the virulent phenotype of HSV-1 strain HFEM [7].

Analytical, diagnostic and therapeutic context of UL56

• A specific DNA fragment (650 bp) was amplified by reverse polymerase chain reaction using oligonucleotide primers corresponding to the predicted translational start and termination region of the UL56 gene [9].
• The presence of the UL56 protein was detected in infected cells and in HSV-1 virions by Western blot experiments and by immunofluorescence assays [4].
• In order to investigate the role of this particular signature of the UL56 protein in the process of viral pathogenicity, site-specific mutagenesis was performed for removing the carboxy-terminus of the UL56 protein [7].
• Identification of the UL56 protein of herpes simplex virus type 1 within the virion by immuno electron microscopy [3].
• An increased mortality of HSV-1-infected mice was observed following intraperitoneal injection of both the pathogenic HSV-1 (Justin) and the apathogenic UL56-deleted HSV-1-M-LacZ strains [10].

References