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P Verde

Publications and source records attributed to P Verde.

27 records · Page 2Linked to original sources
PubMed1988

An upstream enhancer and a negative element in the 5' flanking region of the human urokinase plasminogen activator gene.

The 5' flanking region of the human urokinase (uPA) gene has been fused to the reporter chloramphenicol acetyl transferase (CAT) gene and its activity assayed by transfection in two human cell lines. Progressive deletions of the uPA regulatory region from the 5' end maintain a high level of expression provided at least 1870 (in A1251 cells) or 1963 (in HFS10 cells) nucleotides of the 5' flanking region are retained. A DNA fragment from -2350 to -1824 has enhancer properties, stimulating transcription of an enhancerless SV40 early promoter independently of orientation and distance. Internal deletions that still retain the enhancer element reveal the presence of negative cis-acting sequences between -1824 and -1572. Their removal, in fact, increases uPA transcriptional activity. Differences of expression of the uPA-CAT fusion genes in the two cell lines are also observed, indicating the presence of cell-specific cis-acting sequences.

Amino Acid Sequence↗
PubMed1986

Increase in urokinase plasminogen activator mRNA synthesis in human carcinoma cells is a primary effect of the potent tumor promoter, phorbol myristate acetate.

The effect of tumor promoters and growth factors on the synthesis of urokinase and urokinase mRNA in human carcinoma cells has been investigated. In urokinase-producing human carcinoma cells (A1251), a 20-40-fold increase in urokinase mRNA level is obtained after treatment with 10 nM phorbol myristate acetate (PMA), a smaller effect (two- to fourfold) with 2 ng/ml platelet-derived growth factor (PDGF) and no effect with epidermal growth factor (EGF) (up to 50 nM). After treatment with PMA, urokinase mRNA level increases already at 30 min peaking 2-4 h thereafter. Cell line A431, which has an abnormally high number of EGF receptors, shows the same response to PMA, but also responds to EGF (two- to fourfold increase in mRNA). The kinetics are similar to those of A1251. Nuclear transcription experiments show that the PMA-induced increase in urokinase mRNA is due to increased synthesis. The protein synthesis inhibitor, cycloheximide (10 micrograms/ml), also increases the level of urokinase mRNA. When both cycloheximide and PMA are used, super-induction is observed. This result may indicate that a short-lived protein negatively regulates the level of urokinase. The different efficiency of the effectors (PMA and PDGF better than EGF) and their kinetics, as well as the effect of cycloheximide on urokinase mRNA synthesis, (a) are reminiscent of the effect of PDGF and PMA on competence phase genes (Kelly, K., B.H. Cochran, C.D. Stiles, and P. Leder, 1983, Cell, 35: 603-610), (b) demonstrate that the synthesis of urokinase is part of the early cellular response to these factors, and (c) provide a preliminary insight in the overproduction of urokinase by primary malignant tumors and transformed cells in culture.

Carcinoma, Squamous Cell↗
PubMed1985

The human urokinase-plasminogen activator gene and its promoter.

The urokinase type of plasminogen activator (uPA) is subject to regulation by hormones, phorbol esters and oncogenic transformation. This enzyme has been suggested to play a key role in processes involving cell migration and tissue remodeling, and to be essential for tumor metastasis. In order to study these processes, we have isolated the human uPA gene, and have determined its entire nucleotide sequence. The gene is organized in 11 exons and is 6.4 kb long. The 5' end of uPA mRNA has been determined by both S1 mapping and primer extension experiments. A fragment of 800 bp containing the entire 5' flanking region shows promoter activity when introduced upstream of a bacterial chloramphenicol acetyltransferase gene and introduced into human cells. The hexanucleotide sequence GGCGGG, previously found at similar regions in several viral and eukaryotic promoters and shown to be essential for promoter activity (McKnight et al. (1984) Cell, 37, 253-262), is repeated three times between the CAAT and the TATA boxes.

Base Sequence↗
PubMed1985

Human urokinase gene is located on the long arm of chromosome 10.

Urokinase is one of the two plasminogen activators that catalyze the conversion of inactive plasminogen to plasmin. By combining somatic cell genetics, in situ hybridization, and Southern hybridization, we localized the human urokinase gene on the distal third of the long arm (q24-qter) of chromosome 10.

Chromosome Mapping↗
PubMed1984

Transcriptional induction of urokinase in cultured human kidney carcinoma cells by tetradecanoyl-phorbol-acetate.

A cell line derived from a human kidney carcinoma produces in vitro the urinary type of plasminogen activator (urokinase). The synthesis of plasminogen activator is enhanced by 12-O-tetradecanoyl-phorbol-13-acetate(TPA); the increase can be followed both in the cell lysate and in the culture medium. The effect requires RNA and protein synthesis as well as the continuous presence of the inducer. Immunofluorescence and immunoprecipitation experiments with monospecific antiurokinase IgG show that kidney carcinoma cells synthesize a 50,000-dalton urokinase and TPA enhances the synthesis of the same molecular species. Hybridization of the total cellular RNA to a human urokinase cDNA probe shows that TPA increases the urokinase mRNA level.

Cell Line↗
PubMed1984

Monoclonal antibodies to human urokinase identify the single-chain pro-urokinase precursor.

Monoclonal antibodies have been obtained that recognize either the A or B chain of human urinary urokinase. These antibodies identify human urokinase-producing cells and the product of urokinase mRNA. Anti-urokinase monoclonal antibodies precipitate an approximately equal to 54,000-dalton protein synthesized in vitro in a rabbit reticulocyte cell-free system. This pro-urokinase appears to be the precursor of both A and B chains of human urinary urokinase. Urokinase mRNA in human kidney constitutes only 0.1% or less of total poly(A)+ RNA.

Animals↗
PubMed1984

Identification and primary sequence of an unspliced human urokinase poly(A)+ RNA.

Human urokinase cDNA clones have been identified from a cDNA library prepared from total RNA of human fibroblasts transformed by simian virus 40 [Okayama, H. & Berg, P. (1983) Mol. Cell. Biol. 3, 280-289]. Synthetic oligonucleotides, corresponding to urokinase protein sequence, were used as probes. The cloned cDNA covers most of the coding sequence and the entire 3' untranslated region. The nucleotide sequence of one of the clones identifies this as a copy of a partially spliced polyadenylylated precursor to urokinase mRNA. The introns separate functionally different domains of the enzyme. Human urokinase mRNA has been identified by RNA blot and its size was estimated at 2500 nucleotides.

Base Sequence↗
PubMed1981

Identification, nucleotide sequence and expression of the regulatory region of the histidine operon of Escherichia coli K-12.

A restriction fragment has been isolated and its nucleotide sequence determined. This fragment contains sites for RNA polymerase binding, initiation and termination of transcription of the Escherichia coli histidine operon. In vitro transcription of plasmids containing this region generates one single histidine-specific, attenuated, small RNA: the leader RNA. This RNA is more efficiently transcribed when the template DNA is supercoiled. Another promoter was identified on the same fragment of deoxyribonucleic acid by in vitro transcription, DNA sequencing and RNA polymerase binding. Both promoters, transcribing in opposite direction, are very A-T rich and are separated by a G-C rich region containing a palyndromic structure.

Base Sequence↗