Disease relevance of HpVgp4

• Chimeric bacteriophage fr virus-like particles harboring the immunodominant C-terminal region of hamster polyomavirus VP1 induce a strong VP1-specific antibody response in rabbits and mice [1].
• Phage fr coat protein-derived virus-like particles tolerated the N-terminal fusion of amino acids 333-384, 351-384, 351-374, and 364-384, respectively, of VP1 [1].
• The high flexibility of the C-terminal region of VP1 was confirmed by the formation of chimeric virus-like particles based on the coat protein of the RNA bacteriophage fr which was previously found to tolerate only very short-sized foreign insertions [1].
• Renaturation of the purified VP1 protein resulted in the formation of subunits that were morphologically, biophysically, and immunologically similar to native virion capsomeres [2].
• Electron microscopy showed that isolated recombinant VP1 protein self-assembled into a capsid-like structure similar to the natural empty capsid [3].

Psychiatry related information on HpVgp4

• With DNA extracted from brain specimens from 19 multiple sclerosis, 5 progressive multifocal leukoencephalopathy, 1 Alzheimer's disease, and 8 nonneurological control subjects, polymerase chain reaction was performed using nested sets of primer pairs amplifying segments of the large T and VP1 antigen-encoding sequences of JC virus [4].

High impact information on HpVgp4

• The 3' on OH terminal G of this segment is part of the G-C-C codeword for the N terminal alanine of the VP1 protein [5].
• Expression of capsid antigen VP1 ("late gene products") required at least three GGGCGG boxes, sequences between nucleotides 197 and 273 in the 72-bp repeat region, and transactivation by T-Ag [6].
• The crystal structure of polyoma VP1 with a sialic acid-containing oligosaccharide was used to derive a model of how the two terminal sugars (sialic acid-alpha2,3-galactose) in one branch of GD1a and GT1b are recognized by the virus [7].
• The ability of mutants such as Py1387T to induce S6 phosphorylation correlated with their ability to increase phosphorylation of VP1, an event linked to maturation of infectious virions [8].
• CK II phosphorylated VP1 on serine, and the resulting tryptic phosphopeptide eluted in a 30-31 min high performance liquid chromatography fraction corresponding to residues 58-78 [9].

Chemical compound and disease context of HpVgp4

• Polyomavirus nontransforming host range (hr-t) mutants are defective in VP1 threonine phosphorylation when grown in nonpermissive cells (R. L. Garcea, K. Ballmer-Hofer, and T. L. Benjamin, J. Virol. 54:311-316, 1985) [10].
• Upon expression in Escherichia coli and purification by immunoaffinity chromatography, wild-type VP1 was isolated as pentameric, capsomere-like structures which could be induced to form capsid-like structures upon addition of CaCl2, consistent with previous studies [11].
• We investigated whether the VP1 protein of simian virus 40 binds to DNA [12].
• We used simian virus 40 tsB201 (unable to produce viral capsid at the restrictive temperature of 41 degrees C because of a point mutation in the VP1 gene) to analyze the mutagenic potency of the two major UV-induced lesions, pyrimidine dimers (Py-Py) and pyrimidine (6-4) pyrimidones [Py(6-4)Py], which are formed on the same nucleotide sites [13].
• The use of a tryptophan promoter-driven Escherichia coli expression system resulted in the efficient synthesis of VP1 and VP1(ext) and formation of VLPs [14].

Biological context of HpVgp4

• Existing taxonomic classifications of BKV come from conventional DNA sequence alignments based on limited data derived from the VP1 gene [15].
• The most polymorphic coding region in the viral genome is VP1, but significant variation is also present in the large T-antigen gene, wherein polymorphisms are found in 11.39% of all nucleotide sites, 46.22% of which are cluster specific [15].
• The sequence information needed for assigning genotypes can be captured by VP1, VP2, VP3, or large T-gene sequencing [15].
• The double-stranded genome of the small DNA tumor virus, polyomavirus, is enclosed in a capsid composed of a major protein, VP1, which associates as pentameric capsomeres into an icosahedral structure, and two minor proteins, VP2 and VP3, whose functions and positions within the structure are unknown [16].
• The polyomavirus proteins VP1, VP2, and VP3 move from their cytoplasmic site of synthesis into the nucleus, where virus assembly occurs [17].

Anatomical context of HpVgp4

• For both groups of hamsters in the C-terminal region of VP1 immunodominant B-cell epitopes were identified in the regions between amino acids 305 and 351 and amino acids 351 and 384 [1].
• VP1 protein expressed in E. coli self-assembled into capsid-like particles and caused haemagglutination of human O-type red blood cells [18].
• To identify cellular or viral components which might control this process, we determined the distribution of VP1, VP2, and VP3 in a soluble fraction, a cytoplasmic cytoskeleton fraction, and a nuclear framework fraction of infected cells [17].
• In addition, production of VP1 protein was observed in the T.wt/BL cell line [19].
• VP2 and VP3, but not VP1, caused the permeabilization of bacterial membranes [20].

Associations of HpVgp4 with chemical compounds

• The recombinant production of the VP1 protein offers a save way to obtain a highly purified, non pathogenic pharmaceutical excipient [21].
• Previous mapping of the in vivo phosphorylation sites on VP1 identified phosphorylation of threonine residues Thr-63 and Thr-156 (Li, M., and Garcea, R. L. (1994) J. Virol. 68, 320-327) [9].
• However, although VP1 containing the point mutation was isolated as pentamers which were indistinguishable from wild-type VP1 pentamers, addition of CaCl2 did not result in their assembly into capsid-like structures [11].
• Formic acid cleavage of the 43-kilodalton (kDa) VP1 protein into 29-, 18-, and 16-kDa fragments before 45Ca-binding analysis revealed that only the 18- and 16-kDa carboxyl-terminal fragments of this protein bind 45Ca [22].
• Phosphoamino acid analysis of 32P-labeled VP1 revealed that phosphoserine is the only phosphoamino acid present in the VP1 protein [23].

Other interactions of HpVgp4

• In the PCR assay, both early large T antigen (LT) and late (VP1) transcriptional BKV coding regions were found in renal tissue, whereas EBV and only LT-BK were detected in PTLD abdominal tissue [24].

Analytical, diagnostic and therapeutic context of HpVgp4

• Immunofluorescence studies utilizing Sf9 cells infected with the AcMNPV-VP1 revealed that the VP1 protein was expressed and localized in the cytoplasm and not transported into the nucleus [25].
• Indirect immunofluorescence demonstrated an exclusive nuclear localization of VP1 in situ [17].
• Two phosphorylated peptide fragments of VP1 were identified by protease digestion, high-performance liquid chromatography purification, mass spectrometry, and N-terminal sequencing [10].
• LT, VP1 and TCR-BKV sequence analysis in a patient with post-transplant BKV nephropathy associated with EBV-related PTLD [24].
• Combining these aspects, VP1 proteins provide a targeting as well as a drug binding site when used as a save drug carrier for gene therapy [21].

References