Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q07644 (polypeptide)
 72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infection associated with medical devices may involve bacterial biofilms, a possible cause of antibiotic resistance. Protamine, a basic polypeptide, depresses the metabolic activity of Staphylococcus epidermidis in a standardized biofilm assay. The resistance of the biofilm preparations to many antibiotics, with the sole exception of rifampin, was confirmed. Rifampin produced predominant lysis and killing with foci of genetically programmed resistance. The combination of protamine with antibiotics produced no change, except the combination with rifampin where clear classic synergism with a totally bactericidal outcome was demonstrated. Protamine is a member of the larger family of charged polycations, some of which possess membrane potential altering properties, possibly interfering with the protective nature exhibited by the negatively charged bacterial biofilm matrix.
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PMID:The effect of protamine on antibiotic action against Staphylococcus epidermidis biofilms. 225 82

Infection of A431 cells with vaccinia virus, or exposure to a mitogenic polypeptide secreted by vaccinia virus-infected cells, induces tyrosine phosphorylation of epidermal growth factor receptors.
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PMID:Vaccinia virus growth factor stimulates tyrosine protein kinase activity of A431 cell epidermal growth factor receptors. 243 Dec 67

A monoclonal antibody (MAb) raised against the pore-complex lamina fraction from CV-1 cells was used to study alterations of gene expression in herpes simplex virus type 1 (HSV-1)-infected cells. This MAb, which recognized only one cellular polypeptide of 60,000 Da, selectively stained the nucleus in immunofluorescence microscopy, showing a punctuated pattern either at the nuclear surface or at the nuclear rim. By immunoelectron microscopy, the p60 antigen could be localized in the nuclear pore complex structure. Infection of CV-1 cells with HSV-1 resulted in a drastic change of the nuclear staining pattern. Four hours p.i., a clustering of the p60 antigen and, 12 h p.i., a formation of finger-like holes, penetrating the nucleus, occurred. Later in infection (22 h p.i.) the antigen was found to be almost absent. By RNA blot hybridization it was demonstrated that, after HSV-1 infection, the level of cellular mRNA (beta-tubulin) gradually decreased, while the level of HSV major DNA binding protein (DBP) mRNA increased, reaching maximal level 3-6 h p.i. Interestingly, the level of beta-tubulin gene transcripts changed differentially in the polysomal and in the nuclear fraction during the initial phase of infection, in contrast to the viral DBP transcripts, indicating that, after HSV infection, host cell transcripts accumulate in the nucleus. Evidence is presented indicating that this change is not due to altered nucleocytoplasmic mRNA transport but is due to an impaired splicing of host cell transcripts in HSV-infected cells. The MAb, directed against the nuclear pore p60 antigen, strongly inhibited the ATP-dependent efflux of both cellular and viral mRNA from isolated nuclei. The ATP-dependence of the efflux did not change during viral infection. However, the inhibitory potency of the MAb was found to be lost at the final stage of HSV infection, paralleling the loss of p60 antigen.
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PMID:Change of processing and nucleocytoplasmic transport of mRNA in HSV-1-infected cells. 254 33

We have prepared EMBL3 libraries of DNA extracted from the cervix of a patient with cervical intraepithelial neoplasia (CIN) and isolated seven recombinant clones containing sequences that hybridize to human cytomegalovirus (HCMV) DNA. Restriction analysis of one clone with BamHI and SalI endonucleases revealed that the insert DNA showed a high degree of homology to the HCMV Ad169 genome over the region between the HindIII K/E site and the SalI site located within the BamHI P fragment. The HCMV insert in the CIN clone is integrated and flanked by cellular sequences. The major immediate early gene that encodes a polypeptide of approximately 69 kD was found to be conserved in the CIN clone. Transfection of clones encoding the immediate early region of HCMV resulted in cells that were positive in immunofluorescence studies with two monoclonal antibodies directed against the HCMV 69 kD immediate early polypeptide. Infection of human ectocervical cells with HCMV Ad169 revealed that they could express the 69 kD polypeptide encoded by the immediate early gene but could not replicate the virus, whereas HCMV was able to replicate productively in cultured endocervical cells. HCMV has been shown to activate endogenous retroviruses and also to transcriptionally activate the long terminal repeat of human immunodeficiency virus. Activation of virus and cellular genes by HCMV may be a means by which this virus is involved in the multistage process of oncogenesis and/or the activation of latent infections.
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PMID:Molecular cloning of DNA sequences from cervical intraepithelial neoplasia that hybridize to human cytomegalovirus DNA. 255 81

A poliovirus type 2 Lansing mutant was constructed by inserting 6 base pairs into the 2Apro region of an infectious cDNA clone, resulting in the addition of a leucine and threonine into the polypeptide sequence. The resulting small-plaque mutant, 2A-2, had a reduced viral yield in HeLa cells and synthesized viral proteins inefficiently. Infection with the mutant did not lead to specific inhibition of host cell protein synthesis early in infection, and this defect was attributed to a failure to induce cleavage of the cap-binding complex protein p220. At late times after infection with the mutant virus, both cellular and viral protein syntheses were severely inhibited. To explain this global inhibition of protein synthesis, the phosphorylation state of the alpha subunit of eucaryotic initiation factor 2 (eIF-2 alpha) was examined. eIF-2 alpha was phosphorylated in both R2-2A-2- and wild-type-virus-infected cells, indicating that poliovirus does not encode a function that blocks phosphorylation of eIF-2 alpha. The kinetics and extent of eIF-2 alpha phosphorylation correlated with the production of double-stranded RNA in infected cells, suggesting that eIF-2 alpha is phosphorylated by P1/eIF-2 alpha kinase. When HeLa cells were infected with R2-2A-2 in the presence of 2-aminopurine, a protein kinase inhibitor, much higher virus titers were produced, cleavage of p220 occurred, and host cell protein synthesis was specifically inhibited. Since phosphorylation of eIF-2 alpha was not inhibited by 2-aminopurine, we propose that 2-aminopurine rescues the ability of R2-2A-2 to induce cleavage of p220 by inhibition of a second as yet unidentified kinase.
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PMID:Inhibition of translation in cells infected with a poliovirus 2Apro mutant correlates with phosphorylation of the alpha subunit of eucaryotic initiation factor 2. 255 43

Infection of susceptible fathead minnow or Friend erythroleukemia cells with either infectious or heat-inactivated frog virus 3 led to the rapid inhibition of cellular protein synthesis. As seen in other cells, translational shut-off was accompanied by the dissociation of polysomes, but not the degradation of irreversible inactivation of cellular mRNAs. In addition, lysates from cells infected with heat-inactivated FV3 showed a reduced capacity to synthesize protein and to form 43S pre-initiation complexes in vitro. These results indicate that the in vitro systems accurately reflected in vivo events, and suggest that translational shut-off occurred prior to the union of the 40S ribosomal subunit and the [eIF-2.GTP.Met tRNAi] ternary complex. To determine the basis for the translational block, lysates from mock- and FV3-infected cells were assayed in vitro for their ability to phosphorylate the alpha subunit of eIF-2. In contrast to lysates from mock-infected cells, lysates from cells infected with heat-inactivated or infectious FV3 readily phosphorylated the alpha subunit of eIF-2. Since phosphorylation of the alpha subunit of eIF-2 inhibits its catalytic utilization during polypeptide chain initiation, these findings suggest that translational shut-off mediated by FV3 may be due to activation of a kinase that selectively phosphorylates this key initiation factor.
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PMID:Frog virus 3-induced translational shut-off: activation of an eIF-2 kinase in virus-infected cells. 262 41

Induction of the major stress response in chick embryo fibroblasts, which follows infection at 38.5 degrees C with the herpes simplex virus mutant tsK, was investigated. Synthesis of cellular stress proteins occurred only when the mutant form of an immediate early polypeptide, Vmw175, was overproduced. Infection with mutant in 1411, which has an amber (TAG) termination signal inserted between codons 83 and 84 of the gene encoding Vmw175 and therefore specifies a truncated portion of the polypeptide, failed to stimulate stress protein synthesis. The results suggested that the presence of abnormal forms of Vmw175 at high concentrations was the signal for induction of the stress response in tsK-infected cells.
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PMID:Abnormal forms of the herpes simplex virus immediate early polypeptide Vmw175 induce the cellular stress response. 282 Nov 79

Polymyxins are cyclic polypeptide antibiotics. In addition to their bactericidal activity they bind lipid A and neutralize the biological effects of bacterial endotoxin. We have studied the three available polymyxin preparations: polymyxin B sulphate (PB), colistin sulphate (CS) and colistin sulphomethate sodium (CMS), and compared their endotoxin binding capacity at equivalent therapeutic dosage. Each polymyxin was bound to a column of Sepharose 4B and challenged with 5 micrograms of endotoxin from Escherichia coli O127:B8. Recovery of endotoxin in the eluate was measured by a quantitative Limulus lysate microassay. PB and CS bound 94% of the challenge dose, CMS 89% and the control column (Sepharose alone) 24%. These results suggest that parenteral CMS (the least toxic polymyxin) retains useful anti-endotoxin capacity, and that in neutropenic patients, oral polymyxin may exert both anti-endotoxin and antimicrobial effects.
Infection
PMID:Comparison of the binding of gram-negative bacterial endotoxin by polymyxin B sulphate, colistin sulphate and colistin sulphomethate sodium. 301 78

Four peptides were synthesized on the basis of amino acid sequences deduced from a highly spliced transcript encoded by the Bam W, Y, and H fragments of the Epstein-Barr virus (EBV) genome [Bodescot, M., Chambraud, J. B., Farrell, P. J. & Perricaudet, M. (1984) EMBO J. 3, 1913-1917]. Rabbit antisera against three of the four peptides identified a nuclear polypeptide that varied between 22 and 70 kDa in molecular size. Four of 20 EBV-positive human sera contained antibodies against this polypeptide. Since this is the fifth EBV-determined nuclear antigen (EBNA) discovered in growth-transformed cells, it is designated EBNA5. The antigen was detected in virus nonproducer lines (less than 0.01% EBV early antigen expression) and is thus not dependent on the viral cycle. It was differentially expressed depending on the origin of the lines. All 10 lymphoblastoid cell lines tested expressed EBNA5, but it could not be detected in 10 of 11 EBV-carrying Burkitt lymphoma lines. Infection of tonsillar lymphocytes with the B95-8 strain of EBV induced six EBNA5-specific polypeptides that varied between 41 and 70 kDa in molecular size with regular increments of 6 kDa. This may be due to the fact that the EBNA5 coding sequence includes the Bam W internal repeat. Parallel infection of the EBV-negative Burkitt lymphoma line Ramos with the same viral substrain did not induce detectable levels of EBNA5, nor was this antigen present in permanently EBV-converted Ramos sublines. These findings imply that the expression of the viral genome varies among B cells having different phenotypes.
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PMID:An Epstein-Barr virus (EBV)-determined nuclear antigen (EBNA5) partly encoded by the transformation-associated Bam WYH region of EBV DNA: preferential expression in lymphoblastoid cell lines. 301 41

Human cells infected with adenovirus type 2 (Ad2) or Ad5 require VAI RNA for efficient translation of viral mRNAs at late times after infection. The Ad5 mutant dl-sub720 synthesized neither virus-associated I (VAI) nor VAII RNAs, and infection of human cells with this mutant resulted in reduced virion polypeptide synthesis. Infection of monkey cells with this mutant also resulted in drastic reduction of polypeptide synthesis compared with wild-type (WT) adenovirus infections. Steady-state levels of hexon-specific mRNA were found to be comparable in WT- and mutant-infected monkey cells. The in vitro translation experiments showed that double-mutant- and WT-infected cells contained comparable levels of translatable hexon mRNA (and other adenovirus late mRNAs), suggesting that the severe inhibition of hexon protein synthesis in the VA mutant involves a translation block. Preinfection of monkey cells with simian virus 40 fully restored the efficient translation of this mRNA in the VA mutant infections to the level observed in WT-infected cultures. These results raise the possibility that simian virus 40 may encode or induce factors that suppress the translation block that occurs during adenovirus infections in the absence of the VA RNAs.
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PMID:Suppression of the translation defect phenotype specific for a virus-associated RNA-deficient adenovirus mutant in monkey cells by simian virus 40. 302 70


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