Disease relevance of H5R

• The amino acid sequence of several tryptic peptides derived from the 36-kDa protein showed that the 36-kDa protein was encoded by gene H5R of vaccinia virus [1].
• A recombinant baculovirus was engineered to express the H5R open reading frame [2].
• Consistent with this, the B1R kinase--either expressed in Escherichia coli or highly purified from HeLa cells--phosphorylated a recombinant trpE-H5R fusion protein in vitro [1].

High impact information on H5R

• The temperature-sensitive phenotype of the G5R mutants closely resembled the phenotypes of vaccinia virus mutants carrying conditionally lethal F10R protein kinase and H5R mutations [3].
• On the basis of these findings, we assigned the H5R gene product the name viral late gene transcription factor 4 (VLTF-4) [2].
• Its expression pattern and subcellular distribution suggest that the H5R gene product may have multiple roles in the viral life cycle [2].
• A common subset of peptides was observed, suggesting that some sites on H5R protein are phosphorylated by the B1R kinase in infected cells [1].
• The viral proteins A1L, A2L, G8R, and H5R positively modulate vaccinia virus late gene expression [4].

Chemical compound and disease context of H5R

• In addition, affinity purification of polyhistidine-tagged G2R protein overexpressed in vaccinia virus-infected cells, reported here, results in copurification of the vaccinia H5R protein, previously characterized as a late viral transcription factor [5].

Biological context of H5R

• The different phosphorylation states and cytological locations of the H5R protein suggest it has multiple roles in VV development [6].
• Late gene expression was not required for the H5R protein to accumulate in virosomes--viral DNA synthesis was sufficient [6].
• Immunofluorescence of VV-infected cells in the absence of DNA replication showed that underphosphorylated H5R protein, specifically recognized by antibody, was abundantly distributed throughout the cytoplasm but also present in punctate particles, whereas most of the B1R protein detected was in the punctate particles [6].
• We generated DNA plasmids encoding the A4L, A27L and H5R VacV genes [7].

Associations of H5R with chemical compounds

• These results suggest that some of the multiple threonine sites in the H5R protein are phosphorylated in vivo by the B1R protein kinase [1].

Regulatory relationships of H5R

• These results show that the B1R protein kinase controls the phosphorylation state of the H5R protein synthesised at the early stage in vaccinia-virus-infected cells [8].

Other interactions of H5R

• A temperature-dependent increase of underphosphorylated H5R protein (pI 6.8) was demonstrated in the case of the B1R, but not of the F10L gene [8].
• A panel of N- and C-terminal truncated forms of the A20R protein was tested for interaction with the D4R, H5R, and D5R proteins using the yeast two-hybrid system [9].

Analytical, diagnostic and therapeutic context of H5R

• Most of the H5R protein was underphosphorylated (pI 5.9 to 6.8) and, on centrifugation of cell lysates, was associated with virosomes sedimenting with nuclei [6].
• Association of an epitope-tagged A20R protein with an epitope-tagged D4R or H5R protein, expressed in vaccinia virus-infected cells, was demonstrated by binding the complex to one mAb followed by Western blotting with another [9].
• The phosphorylation state of H5R protein was investigated by two-dimensional gel electrophoresis of proteins of BSC-40 cells infected at 32 degrees or 39.5 degrees with vaccinia virus ts mutants of the viral B1R or F10L protein kinase genes [8].

References