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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adeno-associated virus 2 (AAV), a nonpathogenic human parvovirus, requires co-infection with a helper virus for its optimal replication. Although AAV possesses a broad host range, certain cell types lack the machinery necessary for efficient entry into the cell and intracellular trafficking of AAV into the nucleus, where the viral second-strand DNA synthesis must occur before gene expression. We have demonstrated that in less-permissive mouse fibroblasts, the virus fails to transport to the nucleus due to altered endocytic processing. However, relatively little is known about the intracellular site of viral uncoating and transport of the virion across the nuclear envelope. Here, we provide evidence that AAV can efficiently enter intact nuclei purified from both permissive and less-permissive cell types. Furthermore, entry into the nucleus is time- and temperature-dependent, but is not saturable and seems to occur independently of the nuclear pore complex. We also demonstrate that purified nuclei contain all of the machinery necessary for uncoating and viral second-strand DNA synthesis even in the absence of a helper virus. These studies provide new insights into the basic biology of AAV and may also have implications for the optimal use of AAV vectors in human gene therapy.
Mol Ther 2001 Oct
PMID:Infection of purified nuclei by adeno-associated virus 2. 1159 30

It has become increasingly clear that parvovirus-based vectors are a potentially safe and useful alternative to the more commonly used retroviral and adenoviral vectors. Parvovirus vectors have been successfully used in phase I clinical trials for gene therapy of cystic fibrosis and hemophilia B, and several salient features of these vectors provide further support to the suggestion that their use in potential gene therapy of a wide variety of human diseases is imminent and perhaps well justified.
Curr Opin Mol Ther 2001 Oct
PMID:Parvovirus vectors for human gene therapy. 1169 94

Adeno-associated virus type 2 empty capsids are composed of three proteins, VP1, VP2 and VP3, which have relative molecular masses of 87, 72 and 62 kDa, respectively, and differ in their N-terminal amino acid sequences. They have a likely molar ratio of 1:1:8 and occupy symmetrical equivalent positions in an icosahedrally arranged protein shell. We have investigated empty capsids of adeno-associated virus type 2 by electron cryo-microscopy and icosahedral image reconstruction. The three-dimensional map at 1.05 nm resolution showed sets of three elongated spikes surrounding the three-fold symmetry axes and narrow empty channels at the five-fold axes. The inside of the capsid superimposed with the previously determined structure of the canine parvovirus (Q. Xie and M.S. Chapman, 1996, J. Mol. Biol., 264, 497-520), whereas the outer surface showed clear discrepancies. Globular structures at the inner surface of the capsid at the two-fold symmetry axes were identified as possible positions for the N-terminal extensions of VP1 and VP2.
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PMID:Electron cryo-microscopy and image reconstruction of adeno-associated virus type 2 empty capsids. 1171 91

Parvovirus initiation factor (PIF), identified in HeLa cells as a host factor essential for parvoviral DNA replication, is a ubiquitous heterodimeric cellular transcription factor. This protein complex was simultaneously identified as glucocorticoid modulatory element binding protein (GMEB) by its ability to bind to the glucocorticoid modulating element (GME) upstream of the tyrosine transaminase promoter. Here, we show that the two PIF/GMEB subunits form site-specific DNA-binding heterodimers when co-expressed from recombinant baculoviruses and homodimers when expressed separately. Degenerate oligonucleotide selection experiments, combined with analysis of dissociation rates, established that the three complexes bind to flexibly spaced tetranucleotide half-sites that conform to the consensus ACGPy N(1-9) PuCGPy, with an optimum of N=6. Binding of all three complexes is extremely sensitive to methylation of the cytosine residues in the invariant CpG half-site core, suggesting a means by which PIF/GMEB binding could be regulated in vivo. Because CpG dinucleotides are suppressed in eukaryotic genomes, such binding sites would be expected to be very rare. However, analysis of 100 human promoters showed that over half of them contained at least one site conforming to the consensus, a significant deviation from the expected random distribution. In many of these, the binding site is within 100 nucleotides of the transcriptional start site, indicating that PIF/GMEB may be involved in regulation of these genes. Oligonucleotides corresponding to five of these sequences, chosen to represent the range of half-site separations identified by the consensus, were tested for PIF/GMEB binding by mobility shift assay. All five probes bound the heterodimer efficiently and, in each case, binding was completely abrogated by 5-methylation of the C residues in the CpGs of the putative half-sites.
J Mol Biol 2001 Dec 14
PMID:A consensus DNA recognition motif for two KDWK transcription factors identifies flexible-length, CpG-methylation sensitive cognate binding sites in the majority of human promoters. 1174 20

Human parvovirus B19 is the cause of a common childhood disease that usually has a mild and self-limited course. Complete viral replication and subsequent cell lysis are limited to early erythroid precursor cells expressing the globoside receptor. Individuals with shortened red blood cell half-lives and immunocompromised or immunosuppressed patients, as well as pregnant women and developing fetuses, are at risk for severe anemia and/or persistent infection from human parvovirus B19. Selection of the diagnostic test(s) to use to detect parvovirus B19 is patient dependent. Serological testing is most appropriate in immunocompetent individuals, including children and pregnant women, who have symptoms consistent with parvovirus B19 infection or a history of recent exposure. Conversely, a molecular amplification assay should be chosen to detect parvovirus B19 DNA in individuals lacking an adequate antibody-mediated immune response. In summary, it is critical that clinicians are educated about the most appropriate diagnostic test to detect parvovirus B19 infection in their patients because selecting an inappropriate or inaccurate test for parvovirus B19 can lead to misinformation and/or misdiagnosis.
Mol Diagn 2001 Dec
PMID:Diagnosing human parvovirus B19 infection: guidelines for test selection. 1177 95

The structure of baculovirus-expressed porcine parvovirus (PPV) capsids was solved using X-ray crystallography and was found to be similar to the related canine parvovirus (CPV) and minute virus of mice (MVM). The PPV capsid protein has 57 % and 49 % amino acid sequence identity with CPV and MVM, respectively, but the degree of conservation of surface-exposed residues is lower than average. Consequently, most of the structural differences are on the surface and are the probable cause of the known variability in antigenicity and host range. The NADL-2 and Kresse strains of PPV have distinct tissue tropisms and pathogenicity, which are mediated by one or more of the amino acid residues 381, 386, and 436. These residues are on or near the surface of the virus capsid, where they are likely to be associated with virus-cell interactions.
J Mol Biol 2002 Feb 01
PMID:The structure of porcine parvovirus: comparison with related viruses. 1182 86

We observed a 12-year-old boy with acute hepatitis and associated aplastic anemia (AA), where parvovirus B19 genome was repeatedly detected in liver and bone marrow biopsies, but not in blood samples. We conclude that: (1) B19 infection may be underdiagnosed as the causative agent responsible for acute hepatitis and associated AA if no organ-specific diagnostic tests are applied; (2) B19 deoxyribonucleic acid (DNA) can persist in the liver; (3) during the acute phase of hepatitis, extramedullary hematopoiesis may be involved in the susceptibility for hepatic B19 infection.
Pediatr Pathol Mol Med
PMID:Acute liver disease and aplastic anemia associated with the persistence of B19 DNA in liver and bone marrow. 1184 76

The adeno-associated virus type 2 (AAV) large Rep proteins can act to increase the ratio of spliced to unspliced AAV RNA when they are targeted to the transcription template via a Rep binding element. The required Rep binding site is both location and orientation independent; however, Rep enhancement decreases as the distance between the promoter and the intron of the affected transcription unit increases. Only the AAV intron and an extended polyadenylation site must remain for the AAV transcription unit to manifest responsiveness to Rep. A number of promoters, when driving the AAV capsid gene transcription unit, were responsive to targeted Rep, though to various degrees. Transactivation of transcription initiation is not sufficient for the enhancement of RNA processing, because activation of the P40 transcription unit by other activators targeted to this transcription template did not result in enhancement of the ratio of spliced to unspliced AAV RNA. These results suggest that Rep may act as a trans regulator of RNA processing by modulating such functions coupled to RNA polymerase II (RNA pol II) transcription, perhaps by affecting the composition of the transcription complex either prior to or during elongation. These results reveal another way in which gene expression can be regulated by trans-acting proteins and help explain an important feature of the parvovirus life cycle.
Mol Cell Biol 2002 Jun
PMID:The adeno-associated virus type 2 Rep protein regulates RNA processing via interaction with the transcription template. 1199 1

A rapid and sensitive PCR-ELISA has been developed for detection of hepatopancreatic parvovirus (HPV) in Penaeus monodon. The specific primer set amplified 156 bp fragment and could detect as a little as 0.01 fg of purified HPV DNA which equivalent to three viral particles. No cross-reactivity was observed when nucleic acid templates from white spot syndrome virus, yellow-head virus, monodon baculovirus and shrimp were tested. The crude DNA simple prepared from hepatopancreas can be used as DNA template and provide a favorable result. Using this technique for detection of HPV infection in 87 carrier shrimps revealed the higher sensitivity and efficiency of detection when compared to histological examination and conventional PCR. Sixty-two percent infection was detected by PCR-ELISA from samples with HPV negative diagnosed by histological examination. Therefore, this sensitive and specific method is promisingly useful for early detection of HPV infection in broodstock, carriers and for ex situ application where large numbers of samples can be analyzed simultaneously.
Mol Cell Probes 2002 Dec
PMID:Detection of hepatopancreatic parvovirus (HPV) infection in Penaeus monodon using PCR-ELISA. 1249 Jan 41

The glucocorticoid-modulatory element-binding proteins, GMEB1 and GMEB2, are ubiquitous, multifunctional DNA-binding proteins with important roles in the modulation of transcription upon steroid hormone activation. The GMEB proteins have intrinsic transactivation ability, but also control the glucocorticoid response via direct binding to the glucocorticoid receptor. They are also mandatory host proteins for Parvovirus replication. Here we present the 1.55 A resolution crystal structure of a central portion of GMEB1, encompassing its SAND domain, which shares 80% sequence identity with the GMEB2 SAND domain. We demonstrate that this domain, also present in numerous proteins implicated in chromatin-associated transcriptional regulation, is necessary and sufficient to bind the glucocorticoid-modulatory element (GME) DNA target. We use nuclear magnetic resonance (NMR) and binding studies to map the DNA recognition surface to an alpha-helical region exposing the conserved KDWK motif. Using site-directed mutagenesis, key residues for DNA binding are identified. In contrast to the previously determined NMR structure of the Sp100b SAND domain, we find that the GMEB1 SAND domain also comprises a zinc-binding motif. Although the zinc ion is not necessary for DNA binding, it is found to determine the C-terminal conformation of the GMEB1 SAND domain. We also show that homologous zinc-binding motifs exist in a subset of SAND domain proteins and probe the roles of this novel motif.
Mol Endocrinol 2003 Jul
PMID:Crystal structure and nuclear magnetic resonance analyses of the SAND domain from glucocorticoid modulatory element binding protein-1 reveals deoxyribonucleic acid and zinc binding regions. 1270 33


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