Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.5.1.18 (glutathione S-transferase)
 22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Equine rhinitis A virus strain 393/76 (ERAV.393/76) was passaged in the presence of post-infection ERAV.393/76 equine polyclonal antiserum (EPA). Viruses with increased resistance to neutralization by EPA were obtained after 15 passages. Compared with the parent virus, five plaque-purified, neutralization-resistant mutant viruses, in addition to the non-plaque-purified viruses that were examined, had a Glu-->Lys change at position 658, which is located in the predicted betaE-betaF (EF) loop of VP1. Rabbit antiserum was prepared against the isolated EF loop of ERAV.393/76 VP1 expressed as a fusion protein with glutathione S-transferase. This antiserum bound to purified ERAV.393/76 in Western blots, but not to the neutralization-resistant mutant virus or to ERAV.PERV/62, a naturally occurring ERAV strain that has a Lys residue at position 658. These results suggest that the EF loop of VP1 is involved in a neutralization epitope of ERAV.
J Gen Virol 2004 Sep
PMID:Identification of a neutralizing epitope in the betaE-betaF loop of VP1 of equine rhinitis A virus, defined by a neutralization-resistant variant. 1530 48

The herpes simplex virus UL56 gene product is a C-terminal-anchored, type II membrane protein of unknown function. UL56 was found to interact with KIF1A, a member of the kinesin-3 family, in a yeast two-hybrid screen and a GST pull-down assay. KIF1A mediates the transport of synaptic vesicle precursors and is essential for the function and viability of neurons. When overexpressed, KIF1A co-localized with full-sized UL56, but no clear co-localization was observed when co-expressed with the UL56 mutant protein lacking its C-terminal transmembrane domain (TMD). Although the C-terminal TMD was not essential for the interaction with KIF1A in the yeast two-hybrid screen and GST pull-down assays, these results indicate that the C-terminal TMD, as well as aa 69-217, of UL56 are important for the interaction with KIF1A in vivo. The hypothesis that the UL56 protein affects vesicular trafficking in infected cells, potentially by acting as a receptor for motor proteins in neurons, is discussed.
J Gen Virol 2005 Mar
PMID:Herpes simplex virus type 2 membrane protein UL56 associates with the kinesin motor protein KIF1A. 1572 11

A yeast two-hybrid screen using EBNA3C as bait revealed an interaction between this Epstein-Barr virus (EBV)-encoded nuclear protein and the C8 (alpha7) subunit of the human 20S proteasome. The interaction was confirmed by glutathione S-transferase (GST) pull-down experiments and these also revealed that the related proteins EBNA3A and EBNA3B can bind similarly to C8/alpha7. The interaction between these viral proteins and GST-C8/alpha7 was shown to be significantly more robust than the previously reported interaction between C8/alpha7 and the cyclin-dependent kinase inhibitor p21(WAF1/CIP1). Co-immunoprecipitation of the EBNA3 proteins with C8/alpha7 was also demonstrated after transfection of expression vectors into B cells. Consistent with this ability to bind directly to an alpha-subunit of the 20S proteasome, EBNAs 3A, 3B and 3C were all degraded in vitro by purified 20S proteasomes. However, surprisingly, no sign of proteasome-mediated turnover of these latent viral proteins in EBV-immortalized B cells could be detected, even in the presence of gamma interferon. In actively proliferating lymphoblastoid cell lines, EBNAs 3A, 3B and 3C appear to be remarkably stable, with no evidence of either de novo synthesis or proteasome-mediated degradation.
J Gen Virol 2005 May
PMID:Epstein-Barr virus EBNA3 proteins bind to the C8/alpha7 subunit of the 20S proteasome and are degraded by 20S proteasomes in vitro, but are very stable in latently infected B cells. 1583 37

The NS3 protein of hepatitis C virus (HCV) has a serine protease activity in its N-terminal region, which plays a crucial role in virus replication. This region has also been reported to interact not only with its viral cofactor NS4A, but also with a number of host-cell proteins, which suggests a multifunctional feature of NS3. By means of yeast two-hybrid screening using an N-terminal region of NS3 as bait, a human cDNA encoding a region of ELKS-delta, a member of a novel family of proteins involved in intracellular transport and secretory pathways, was molecularly cloned. Using co-immunoprecipitation, GST pull-down and confocal and immunoelectron microscopic analyses, it was shown that full-length NS3 interacted physically with full-length ELKS-delta and its splice variant, ELKS-alpha, both in the absence and presence of NS4A, in cultured human cells, including Huh-7 cells harbouring an HCV subgenomic RNA replicon. The degree of binding to ELKS-delta varied with different sequences of the N-terminal 180 residues of NS3. Interestingly, NS3, either full-length or N-terminal fragments, enhanced secretion of secreted alkaline phosphatase (SEAP) from the cells, and the increase in SEAP secretion correlated well with the degree of binding between NS3 and ELKS-delta. Taken together, these results suggest the possibility that NS3 plays a role in modulating host-cell functions such as intracellular transport and secretion through its binding to ELKS-delta and ELKS-alpha, which may facilitate the virus life cycle and/or mediate the pathogenesis of HCV.
J Gen Virol 2005 Aug
PMID:Hepatitis C virus NS3 protein interacts with ELKS-{delta} and ELKS-{alpha}, members of a novel protein family involved in intracellular transport and secretory pathways. 1603 67

The cDNA (GenBank, AY251538) encoding bullfrog growth hormone (fGH) was cloned by RT-PCR from the total RNA of pituitary glands. Its sequence encoded a putative polypeptide of 215 amino acids, including a signal peptide of 25 amino acids with no change to those of other previous reported bullfrog GHs. The fGH precursor shares 98.1, 96.3, and 95.3% homologies to those of other bullfrog GHs (AAB24792, AAB19428, CAA31038) in amino-acid sequence and its nucleotide sequences of the coding region shares 99.1 and 98.5% homologies to those of previous bullfrog GH genes (S52027 and X12520). The fGH cDNA was also efficiently expressed in Escherichia coli carrying a plasmid pGfGH in which the cDNA was under the control of GST promoter of pGEX1-lambdaT. The expressed fusion protein GST-fGH is comprised about 29.3% of the total cellular protein in such bacteria. The purified GST-fGH cannot only showed a obvious dose-response curve when it reacted with the hepatic membrane receptor proteins from bullfrog, but also significantly increased the body weight and length of bullfrog after twice injection and such effects lasted two or three weeks after the last injection with purified GST-fGH.
Gen Comp Endocrinol 2006 May 01
PMID:Cloning, expression, and biological activity of growth hormone in bullfrog (Rana catesbeiana). 1644 33

Previous examination of the effect of TCF-4 on transcription of the human immunodeficiency virus type 1 (HIV-1) promoter in human astrocytic cells found that TCF-4 affects the HIV-1 promoter through the GC-rich domain (nt -80 to nt -68). Here, the physical interaction and a functional consequence of TCF4-Sp1 contact were characterized. It was shown that expression of TCF-4 in U-87 MG (human astrocytic) cells decreased basal and Sp1-mediated transcription of the HIV-1 promoter. Results from a GST pull-down assay, as well as combined immunoprecipitation and Western blot analysis of protein extracts from U-87 MG cells, revealed an interaction of Sp1 with TCF-4. Using in vitro protein chromatography, the region of Sp1 that contacts TCF-4 was mapped to aa 266-350. It was also found that, in cell-free extracts, TCF-4 prevented dsDNA-dependent protein kinase (DNA-PK)-mediated Sp1 phosphorylation. Surprisingly, TCF-4 failed to decrease Sp1-mediated transcription of the HIV-1 long terminal repeat (LTR) and Sp1 phosphorylation in cells expressing HIV-1 Tat. Results from immunoprecipitation/Western blotting demonstrated that TCF-4 lost its ability to interact with Sp1, but not with Tat, in Tat-transfected cells. Taken together, these findings suggest that activity at the HIV-1 promoter is influenced by phosphorylation of Sp1, which is affected by Tat and DNA-PK. Interactions among TCF-4, Sp1 and/or Tat may determine the level of viral gene transcription in human astrocytic cells.
J Gen Virol 2006 Jun
PMID:Human immunodeficiency virus type 1 Tat prevents dephosphorylation of Sp1 by TCF-4 in astrocytes. 1669 Sep 26

BHRF1, an early gene product of Epstein-Barr virus (EBV), is structurally and functionally homologous to Bcl-2, a cellular anti-apoptotic protein. BHRF1 has been shown to protect cells from apoptosis induced by numerous external stimuli. Nasopharyngeal carcinoma is an epithelial cancer associated closely with EBV infection. Specific proteins that might interact with and modulate the BHRF1 anti-apoptotic activity in normal epithelial cells are of interest. Therefore, a cDNA library derived from normal human foreskin keratinocytes was screened by the yeast two-hybrid system and a cellular gene encoding human vaccinia virus B1R kinase-related kinase 2 (VRK2) was isolated. Interaction between the cellular VRK2 and viral BHRF1 proteins was further demonstrated by glutathione S-transferase pull-down assays, confocal laser-scanning microscopy and co-immunoprecipitation. Analyses of VRK2-deletion mutants revealed that a 108 aa fragment at the C terminus was important for VRK2 to interact with BHRF1. For BHRF1, aa 1-18 and 89-142 were crucial in interacting with VRK2 and these two regions are counterparts of Bcl-2 homology domains 4 and 1. Overexpressed VRK2 alone showed a modest effect in anti-apoptosis and appeared to enhance cell survival in the presence of BHRF1. However, this enhancement was not observed when VRK2 was co-expressed with Bcl-2. The results indicate that human VRK2 interacts specifically with EBV BHRF1 and that the interaction is involved in protecting cells from apoptosis.
J Gen Virol 2006 Oct
PMID:Human cellular protein VRK2 interacts specifically with Epstein-Barr virus BHRF1, a homologue of Bcl-2, and enhances cell survival. 1696 44

Porcine circovirus type 2 (PCV2) is an important porcine pathogen that establishes persistent subclinical infections but may, on activation, contribute to the development of post-weaning multisystemic wasting syndrome (PMWS). This disease is characterized by weight loss, respiratory or digestive disorders and enlarged lymph nodes with lymphocyte depletion. The molecular mechanisms behind the development of the disease are completely unknown. In order to clarify functions of the different viral proteins and, if possible, to connect these new findings to molecular mechanisms behind the pathogenesis or the viral life cycle, a bacterial two-hybrid screening of a porcine expression library from PK-15A cells was conducted. Using viral proteins corresponding to ORFs 1, 2, 3 and 4 as bait, a number of interactions were identified and two of them were chosen for further characterization. GST pull-down assays confirmed that viral replicase (Rep) interacted with an intermediate filament protein, similar to human syncoilin, and with the transcriptional regulator c-myc. Furthermore, interactions of the viral proteins to each other revealed an interaction between PCV2 Rep and the capsid (Cap) protein and Cap to itself.
J Gen Virol 2006 Nov
PMID:Porcine circovirus type 2 replicase binds the capsid protein and an intermediate filament-like protein. 1703 Aug 55

The respiratory syncytial virus (RSV) phosphoprotein (P) is a major polymerase co-factor that interacts with both the large polymerase fragment (L) and the nucleoprotein (N). The N-binding domain of RSV P has been investigated by co-expression of RSV P and N proteins in Escherichia coli. Pull-down assays performed with a series of truncated forms of P fused to glutathione S-transferase (GST) revealed that the region comprising the last nine C-terminal amino acid residues of P (233-DNDLSLEDF-241) is sufficient for efficient binding to N. Site-directed mutagenesis shows that the last four residues of this peptide are crucial for binding and must be present at the end of a flexible C-terminal tail. The presence of the P oligomerization domain (residues 100-160) was an important stabilizing factor for the interaction. The tetrameric full-length P fused to GST was able to pull down both helical and ring structures, whereas a monomeric C-terminal fragment of P (residues 161-241) fused to GST pulled down exclusively RNA-N rings. Electron-microscopy analysis of the purified rings showed the presence of two types of complex: undecamers (11N) and decamers (10N). Mass-spectrometry analysis of the RNA extracted from rings after RNase A treatment showed two peaks of 22,900 and 24,820 Da, corresponding to a mean RNA length of 67 and 73 bases, respectively. These results suggest strongly that each N subunit contacts 6 nt, with an extra three or four bases further protected from nuclease digestion by the ring structure at both the 5' and 3' ends.
J Gen Virol 2007 Jan
PMID:The nine C-terminal amino acids of the respiratory syncytial virus protein P are necessary and sufficient for binding to ribonucleoprotein complexes in which six ribonucleotides are contacted per N protein protomer. 1717 Apr 52

All of the non-structural proteins of poliovirus, including their processing precursors, are involved in the replication of the viral RNA genome. These proteins assemble into a replication complex, which also contains the viral RNA and cellular factors. An understanding of how these viral proteins interact with each other would enhance our understanding of the molecular events occurring during poliovirus infection of the cell. Previously, we have employed the yeast two-hybrid system to construct two separate linkage maps for the polioviral P2 and P3 proteins, respectively. In the present study, we have searched for interacting pairs between the P2 and P3 proteins in a similar inducible yeast two-hybrid system. Although, the primary functions of the proteolytic products of the P2 and P3 domains of the polyprotein in the viral life cycle are different, we observed significant interactions between 2C(ATPase) and 3AB; 2A(pro) and 3A, 3C(pro) or 3D(pol); 2B and 3A or 3AB. All of the interactions were measured in the yeast two-hybrid system by exchanging the interacting pairs on the transcription-activation and DNA-binding constructs. In vitro GST pull-down assay suggested that the 2C(ATPase)/3AB interaction involves both ionic and hydrophobic contacts between the two proteins. The possible biological implication of the interactions observed in the yeast two-hybrid system will be discussed.
J Gen Virol 2007 Aug
PMID:Complete protein linkage map between the P2 and P3 non-structural proteins of poliovirus. 1762 30


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