TY - JOUR A1 - Maurer, Bernd A1 - Serfling, Edgar A1 - ter Meulen, Volker A1 - Rethwilm, Axel T1 - Transcription factor AP-1 modulates the activity of the human foamy virus long terminal repeat N2 - The human foamy virus (HFV) contains within the UJ region of its long terminal repeat (L TR) three perfect consensus sequences for the binding of the inducible transcription factor AP-1. Results of DNase I footprint protection and gel retardation assays demonstrated that proteins in extracts of HeLa and BHK-21 cells as weil as bacterially expressed Jun and Fos proteins bind to these AP-1 sites. By conducting transient expression assays using chloramphenicol acetyltransferase plasmids carrying LTR sequences with point-mutated AP-1 sites it was found that the three AP-1 sites contribute to the optimal activity ofthe HFV promoter. It is shown that lnduction of the HFV L TR by 12-O-tetradecanoylphorbol-13-acetate (TPA) and serum factors is mediated through the AP-1 sites. KW - Virologie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61444 ER - TY - JOUR A1 - Netzer, Kai O. A1 - Rethwilm, Axel A1 - Maurer, Bernd A1 - ter Meulen, Volker T1 - Identification of the major immunogenic structural proteins of human foamy virus N2 - We have identified the major immunogenic structural proteins of the human foamy virus (HFV), a distinct member of the foamy virus subfamily of Retroviridae. Radiolabelied viral proteins were immunoprecipitated from HFV -infected cells by foamy virus antisera of human and non-human primate origin. Precipitated viral proteins were in the range of 31 K to 170K. Labelling of proteins with [\(^{14}\)C]glucosamine or with [\(^{35}\)S]methionine in the presence oftunicamycin, as well as endo-ß-N-acetylglycosaminidase Hand F treatment of [\(^{35}\)S]methionine-labelled proteins, revealed three viral glycoproteins of approximately 170K, 130K and 47K, most likely representing the env gene-encoded precursor, the surface glycoprotein and the transmembrane protein of HFV, respectively. KW - Virologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61477 ER - TY - JOUR A1 - Rethwilm, Axel A1 - Mori, Kazuyasu A1 - Maurer, Bernd A1 - ter Meulen, Volker T1 - Transacting transcriptional activation of human spumaretrovirus LTR in infected cells N2 - The long terminal repeat (LTR) of the human spumaretrovirus (HSRV) was examined with respect to its ability to function as transcriptional promotor in virus-infected and uninfected cells. Transient transfections using a plasmid in which the 3' L TR of HSRV was coupled to the bacterial chloramphenicol cetyltransferase (cat) gene revealed that the Ievei of HSRV LTR-directed cat gene expression was markedly increased in HSRV-infected cells compared to uninfected cells. Northern blot analysis of cat mRNA from transfected cultures suggests that transactivation of HSRVdirected gene expression occurs at the transcriptionallevel. KW - Virologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61488 ER - TY - JOUR A1 - Rethwilm, Axel A1 - Baunach, Gerald A1 - Netzer, Kai O. A1 - Maurer, Bernd A1 - Borisch, Bettina A1 - ter Meulen, V.olker T1 - Infectious DNA of the human spumaretrovirus N2 - An infectious molecular clone (pHSRV) of the human Spumaretrovirus (HSRV) was constructed using viral DNA and cDNA clones. The infectivity of pHSRV was proven by transfection of cell cultures and subsequent infection of susceptible cultures with cell free transfection derlved virus. pHSRV derived virus produced foamy virus typical cytopathic effects in susceptible cultures. lnfected cells could be stained specifically with foamy virus antisera by means of indirect immunofluorescence. Radiolmmunoprecipltatlon revealed the presence of characteristic HSRV structural proteins in pHSRV infected cultures. By cotransfection of pHSRV and an indicator plasmid it was found that pHSRV is able to transactivate the viral L TR. Viral transcripts were found to be approximately 200 bases Ionger in pHSRV infected cultures compared to wildtype infected cultures. This difference is most likely due to an Insertion of DNA of non-viral origin ln the U3 region of the 3'L TR of the infectious clone. KW - Virologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61495 ER - TY - JOUR A1 - Flügel, Rolf M. A1 - Rethwilm, Axel A1 - Maurer, Bernd A1 - Darai, Gholamreza T1 - Nucleotide sequence analysis of the env gene and its flanking regions of the human spumaretrovirus reveals two novel genes N2 - Recombinant clonesthat represent the 3' part ofthe genome of the human spumaretrovirus (foamy virus) were established from viral DNA and from DNA complementary to viral RNA. The recombinant clones were characterized by blot hybridizations and nucleotide sequence analysis. The deduced protein sequence of the clones at their 5' ends was found to be homologous to the 3' domain of retroviral reverse transcriptases. Downstream of a small intergerne pol-env region a long open reading frame of 985 amino acid residues was identified that according to its genomic location, size, glycosylation signals, and hydrophobicity protile closely resembles the lentiviral env genes. The spumaretroviral env gene is followed by two open reading frames, termed bel-l and bel-2 which are located between env and the long terminal repeat region. The long terminal repeat of 1259 nucleotides is preceded by a polypurine tract and contains the canonical signal sequences characteristic for transcriptional regulation of retroviruses. The provisional classitication of the spumaretrovirus subfamily is discussed. KW - Virologie KW - foamy retrovirus KW - DNA sequence KW - reverse transcriptase KW - transmembrane protein Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61509 ER - TY - JOUR A1 - Rethwilm, Axel A1 - Darai, G. A1 - Rösen, A. A1 - Maurer, Bernd A1 - Flügel, Rolf M. T1 - Molecular cloning of the genome of human spumaretrovirus N2 - DNA ofhuman spumaretrovirus (HSRV) was cloned from both cDNA and from viral DNA into phage A and bacterial plasmid vectors. The recombinant plasm.ids harboring viral DNA were characterized by Southern blot hybridization and restriction mapping. Physical maps were constructed from cDNA and found to be colinear with the restriction maps obtained from viral DNA. The recombinant clones isolated contained viral DNA inserts which rangein size from 2.2 kb to 15.4 kb. The recombinant clones allowed to construct a physical map of the complete HSRV provirus of 12.2 kb. KW - Virologie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61518 ER - TY - JOUR A1 - Flügel, Rolf M. A1 - Maurer, Bernd A1 - Bannert, Helmut A1 - Rethwilm, Axel A1 - Schnitzler, Paul A1 - Darai, Gholamreza T1 - Nucleotide sequence analysis of a cloned DNA fragment from human cells reveals homology to retrotransposons N2 - During molecular cloning of proviral DNA of human. spumaretroVirus, various recombinant clones were estabUshed and analyzed. Blot hybridization revealed that one of the recoinbinant plasmids bad the characteristic features of a member of the long interspersed repetitive sequences famlly. The DNA element was analyzed by restrictioil mapping and nuelootide sequencing. It showed a high degree of amino acid sequence homology of 54.3% when conipared with the 5'-terminal part of the pol gelie product of the murine retrotransposon LIMd. The 3' region of the cloned DNA element encodes proteins witb an even higher degree of homology of 67.4% in comparison to the corresponding parts of a member of the primate Kpnl sequence family. KW - Virologie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61525 ER - TY - JOUR A1 - Baunach, Gerald A1 - Maurer, Bernd A1 - Hahn, Heidi A1 - Kranz, Manuela A1 - Rethwilm, Axel T1 - Functional analysis of human foamy virus accessory reading frames N2 - No abstract available KW - Virologie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61398 ER - TY - JOUR A1 - Netzer, Kai O. A1 - Schliephake, Andreas A1 - Maurer, Bernd A1 - Watanabe, Rihito A1 - Aguzzi, Adriano A1 - Rethwilm, Axel T1 - Identification of pol-related gene products of human foamy virus N2 - Human foamy viruspol gene fragments were molecularly cloned into a procaryotic expression vector. The expression pattern of the cloned fragments and nucleotide sequence analysis of the 5' pol gene region revealed that in HFV the protease (PR) is located in the pol open reading frame. Purified recombinant proteins were used to generate antibodies in rats. ln immunoblot assay, using infected cells as antigen, a precursor protein with an apparent molecular mass (M,) of 127K was identified by antibodies directed against the reverse transcriptase (RT), RNaseH, or integrase (IN) domeins of pol. With concentrated virus as antigen, the RT and RNaseH antibodies recognized a protein of 80K, the IN antiserum recognized a protein of 40K, and the PR antiserum detected a protein of approximately 10K. KW - Virologie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61429 ER -