Armin P E T E R Czernilofsky (original) (raw)

Papers by Armin P E T E R Czernilofsky

PROCEDURE FOR COMPARATIVE STUDY WITH HIGH PERFORMANCE WITH EFFECT SUBSTANCES FARMACOLOGICO. SUBST... more PROCEDURE FOR COMPARATIVE STUDY WITH HIGH PERFORMANCE WITH EFFECT SUBSTANCES FARMACOLOGICO. SUBSTANCES ARE CARRIED ON A STAGE OF THE PROCEDURE FOR COMPARISON cells containing one or more molecules DIANA, BEARING IN MOLECULES A composition BASICA IDENTICA, which differ by the molecule DIANA AND / OR CELLS WITH BASIC STRUCTURE DIFFERENT BIOLOGICAL AND MOLECULES DIANA IDENTICAL. THE EFFECT OF SUBSTANCES ON DIANA activity of molecules is measured by a determination system KINGDOM TO ACTIVATE target molecule and compared DIRECTLY WITH THE EFFECT ON DIANA other molecules.

DNA, 1985

The cellular tandemization of the herpes simplex virus (HSV) thymidine kinase (tk) gene was studi... more The cellular tandemization of the herpes simplex virus (HSV) thymidine kinase (tk) gene was studied in tk- mouse fibroblasts after gene transfer by microinjection into the nucleus or by calcium phosphate-mediated transfection. Three different DNA substrates, designed to yield simple integration patterns, were used: a gel-purified 3.6-kb Bam HI fragment containing the HSV tk gene; the same fragment self-ligated; and the 3.6-kb fragment ligated to a Bam HI-cleaved subset of genomic mouse DNA. The genomic DNA of six independently isolated transformed cell lines was analyzed by Southern blotting and the structure of the tk-specific DNA was studied. The data suggest that modifications (mutations, deletions, recombination events, and recircularization, etc.) of the input DNA fragment occur early after its introduction into the cell. Subsequently these structures are multiplied in a directional manner, generating larger arrays of DNA with distinct and regularly repeated areas. These concatemers can eventually be integrated into the host genome.

Tailoring Genes for Crop Improvement, 1987

Go to AGRIS search. Fate and expression of vector DNA in plant cells. ...

Proceedings of the National Academy of Sciences, 1974

p - Nitrophenylcarbamyl - phenylalanyl-tRNA binds to ribosomes in response to poly(U) and reacts ... more p - Nitrophenylcarbamyl - phenylalanyl-tRNA binds to ribosomes in response to poly(U) and reacts with ribosomal proteins via covalent bond formation. Ribosomal proteins of Escherichia coli were characterized by two-dimensional gel electrophoresis and by reaction with specific antibodies. The affinity label is shown to react with the 50S proteins L27, L15, L2, L16, and L14. We therefore conclude that these particular proteins are located at or near tRNA-binding sites within the 50S ribosomal subunit.

Nucleic Acids Research, 1980

The genarnes of mnmerous avian retroviruses contain at their 3' termini a conserved danain denote... more The genarnes of mnmerous avian retroviruses contain at their 3' termini a conserved danain denoted "c". The precise boundaries and function of "c" have been enigmas. In an effort to resolve these issues, we determined the sequence of ovrer 900 rncleotides at the 3' end of the genom of the Schmidt-Ruppin subgroup A strain of avian sarcoa virus (ASV). We obtained the sequence from a suitable fragment of ASV IX that had been cloned into the single-stranded E phage M13np2. Coputer-assisted analysis of the sequence revealed the following structural features: i) the length of mc"-473 nucleotides; ii) the 3' terminal domain of src, ending in an amber codon at the 5' boundary of "c"; iii) terminator Cdons that preclude continuous translation from "c"; iv) suitably located sequences that my serve as signals for the initiaticn of viral RIA synthesis and for the processing and/or polyadenylaticn of viral M; v) a repeated sequence that flanks src and that could facilitate deletion of this gene; vi) repeated se quences within wc"; and vii) unexplained hanologies between sequences in "c" and sequences in several other reicacids, including the 5' terminal dmairt.W the ASV genomae, tR and its inversion, the cooplenwt of tR4 and its inversion, and the 18S MA of eukaryotic rib-ones. We conclude that "c" probably does not encode a protein, but its sequence may nevertheless serve several essential functions in viral replication. m1e haploid gerxne of avian saroma virus (ASV) is a singlestranded RI conpoxed of ca. 9500 nucleotides (1). This RW fills tw roles during the viral life cycle. First, it serves as niM for the synthesis of several viral polypeptides (1); accordingly, the RM is capped (2) and polyaderylated (3) at the 5' and 3' termini, respectively. Second, the viral genane is the tenplate for synthesis of viral CMz by reverse transcriptase (1,4); the product of this synthesis is integrated into the gerxne of the host cell and transcribed into progeny viral RA (1,5). Tw structural features of the viral genome have been inplicated in the synthesis of viral DNA: a molecule of tRaTrP located near the 5' end of the viral RIA serves as primer

Molecular and General Genetics MGG, 1985

Genetic transformation of Nicotiana tabacum protoplasts was achieved by incubation of protoplasts... more Genetic transformation of Nicotiana tabacum protoplasts was achieved by incubation of protoplasts with a plasmid DNA-calcium phosphate coprecipitate, followed by fusion of the protoplasts in the presence of polyvinyl alcohol and subsequent exposure to high pH. A derivative of the plasmid pBR322 containing a chimaeric gene, consisting of the nopaline synthase promoter, the coding region of the aminoglycoside phosphotransferase gene of Tn5 and the polyadenylation signal region of the octopine synthase gene, was used for ...

MGG Molecular & General Genetics, 1977

p-Nitrophenoxycarbonyl-3H-phenylalanyl-tRNAyeastPhebinds to 80S rat liver ribosomes and forms a c... more p-Nitrophenoxycarbonyl-3H-phenylalanyl-tRNAyeastPhebinds to 80S rat liver ribosomes and forms a covalent bond with ribosomal proteins. The affinity labeled proteins were identified by a kind of “three-dimensional” electrophoresis: groups of 80S proteins were cut out of two-dimensional gel slabs, eluted, and separated by electrophoresis in polyacrylamide gels containing sodium dodecyl sulfate; finally, the radioactivity in the protein bands was determined. The proteins

Journal of Receptors and Signal Transduction, 1995

The neurokinin receptor family is known to modulate phospholipase C activity. In order to find ne... more The neurokinin receptor family is known to modulate phospholipase C activity. In order to find new compounds modulating the activity of these receptors we have developed a cellular screening system that measures the biological activity of receptors coupled to the IP3/DAG signal transduction pathway via the transcriptional activation of a reporter gene. For the establishment of neurokinin test cell lines the reporter cell line A20, stably transformed with the luciferase gene under the control of a promoter containing TPA response elements (TRE), which did not respond to neurokinin agonists, was used. Stable test cell lines were developed by transfecting the reporter cell line A20 with the genes for the human neurokinin receptors NK1, NK2 or NK3, respectively. In these cell lines, expression of luciferase was inducible by substance P, neurokinin A and neurokinin B, respectively. The order of potency of the three neurokinins substance P, neurokinin A and neurokinin B was consistent with published data and results from ligand binding studies performed with the NK1 and NK2 test cell lines. The agonistic effect of the neurokinins could be inhibited in a dose-dependent manner by simultaneous addition of neurokininspecific antagonists like the non-peptide antagonists CP-99,994 and SR 48968.

Journal of Receptor Research, 1993

A large number of G-protein coupled receptors are known to modulate adenylyl cyclase activity. In... more A large number of G-protein coupled receptors are known to modulate adenylyl cyclase activity. In order to find new compounds modulating the activity of specific receptor subtypes we developed a cellular screening system that measures the biological activity of drugs acting on receptors rather than merely their binding characteristics. The activity of the receptor coupling to the cAMP signal transduction pathway was measured via transcriptional activation of a reporter gene. A chinese hamster ovary cell line was stably transformed with a reporter plasmid containing the firefly luciferase gene under the transcriptional control of multiple cAMP responsive elements (CRE). This CRE reporter cell line exhibited 20 to 30-fold induction of luciferase activity upon stimulation of adenylyl cyclase with forskolin, but did not respond to dopamine agonists. Stable test cell lines were developed by transfecting reporter cell lines with human dopamine D1 and D5 receptor genes, respectively. Treatment of these test cell lines with dopamine receptor agonists and antagonists modulated the luciferase expression in a dose-dependent manner. The rank of potency of dopamine receptor agonists and antagonists was in agreement with reported data obtained from binding studies. The non-isotopic assay can be performed in microtiter plate format and is far less work intensive than the determination of adenylyl cyclase activity by direct cAMP measurement. This technology could also be utilized for discovery of new classes of compounds, e.g. allosteric effectors or non competitive ligands.

Journal of Biological Chemistry, 1999

Interleukin-5 (IL-5), expressed primarily by type-2 T helper (Th2) cells, plays an important role... more Interleukin-5 (IL-5), expressed primarily by type-2 T helper (Th2) cells, plays an important role in the development of allergic diseases, such as allergic asthma. Studying the regulation of IL-5 gene expression by Ets transcription factors, we found that Ets1 and Ets2, but not Elf-1, were able to activate the human IL-5 promoter in Jurkat T-cells. This required the presence of either phorbol 12-myristate acetate (PMA) plus ionomycin or PMA plus the viral protein HTLV-I Tax 1. By mutation studies, it could be shown that Ets1 and Ets2 exerted their effects on the IL-5 promoter through a GGAA motif within the Cle0 element. In myeloid Kasumi cells, Ets1 and Ets2 failed to stimulate IL-5 promoter activity, unless the T-cell specific transcription factor GATA3 was added. These results show, for the first time, that Ets1 and Ets2 are able to cooperate with GATA3. Both ionomycin and Tax 1 increased the combined effect of GATA3 with Ets1 and Ets2 in the presence of PMA. The data further demonstrate that, in addition to Ets1, Ets2 is also able to functionally cooperate with Tax 1. The synergism of GATA3 with either Ets1 or Ets2 may play an important role in calcium-or Tax 1-dependent regulation of IL-5 expression in Th2 cells or in HTLV-I transformed adult T-cell leukemia cells, respectively.

European Journal of Pharmacology: Molecular Pharmacology, 1993

The cloned human serotonin 1D (5-HTaD) receptor has been shown to inhibit adenylate cyclase while... more The cloned human serotonin 1D (5-HTaD) receptor has been shown to inhibit adenylate cyclase while the corresponding cloned dog receptor has been characterized by its enhancement of cAMP accumulation. To resolve this apparent discrepancy, the human 5-HT1D receptor has been cloned and expressed in Chinese hamster ovary (CHO) cells and the corresponding dog receptor expressed in mutant Y1 adrenal (YI Kin-8) cells. It is shown that both receptors when activated by sumatriptan depress forskolin induced adenosine 3'5'-cyclic monophosphate (cAMP) accumulation by a pertussis toxin sensitive mechanism, presumably involving G i (the adenylate cyclase inhibitory GTP transducing protein). In the absence of forskolin, the dog receptor enhances cAMP accumulation, thus activating G s (the adenylate cyclase stimulatory GTP transducing protein). When its overriding action on G i is blocked by pertussis toxin pretreatment, the human receptor also enhances cAMP accumulation. Thus both 5-HT~D receptors activate markedly G i and to a lesser extent G s and can exert opposite effects on the same effector system, adenylate cyclase.

DNA, 1986

To compare the effects of different transformation methods on the integration behavior and struct... more To compare the effects of different transformation methods on the integration behavior and structural stability of integrated foreign genes in plant cells, tobacco protoplasts were transformed with Escherichia coli plasmid pLGV2103neo DNA using the Ca phosphate DNA coprecipitation technique. Parallel transformations were done by cocultivation with Agrobacterium tumefaciens harboring the Ti plasmid derivatives pGV3850::2103neo or pGV3850::1103neo. A comparison of the fine structure of the integrated donor DNA obtained by direct gene transfer and by cocultivation indicates that the donor DNA in cells transformed by the former technique undergoes structural changes and concatemerizations, while the DNA integrated by the latter procedure is often unaltered. The cotransformed nopaline synthase gene, which is present in the donor Ti plasmid DNA, was inactivated in two out of nine cases. Once integrated, the arrays of selectable marker DNA appear to be structurally stable under different cell culture and selection conditions, as well as after genetic transmission.