Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A computer-based statistical evaluation of the optimal alignments of the kringle domains of human plasminogen, human prothrombin, human tissue plasminogen activator, human urokinase, and human coagulation Factor XIIa, as well as the putative kringle of human haptoglobin, has been performed. A variety of different alignments has been examined and scores calculated in terms of the number of standard deviations (SD) of a given match from randomness. With the exception of human haptoglobin, it was found that very high alignment scores (8.9-23.0 SD from randomness) were obtained between each of the kringles, with the kringle 1 and kringle 5 regions of human plasminogen displaying the highest similarity, and the S kringle of human prothrombin and the human Factor XII kringle showing the least similarity. The relationships obtained were employed to construct an evolutionary tree for the kringles. The predicted alignments have also allowed nucleotide mutations in these regions to be evaluated more accurately. For those regions for which nucleotide sequences are known, we have employed the maximal alignments from the protein sequences to assess nucleotide sequence similarities. It was found that a range of approximately 40-55% of the nucleotide bases were placed at identical positions in the kringles, with the highest number found in the alignment of the two kringles of human tissue plasminogen activator and the lowest number in the alignment of the S kringle of prothrombin with the second kringle of tissue plasminogen activator. From both protein and nucleotide alignments, we conclude that haptoglobin is not statistically homologous to any other kringle. Secondary structural comparisons of the kringle regions have been predicted by a combination of the Burgess and Chou-Fasman methods. In general, the kringles display a very high number of beta-turns, and very low alpha-helical contents. From analysis of the predicted structures in relationship to the functional properties of these domains, it appears as though many of their functional differences can be related to possible conformational alterations resulting from amino acid substitutions in the kringles.
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PMID:The genetic relationships between the kringle domains of human plasminogen, prothrombin, tissue plasminogen activator, urokinase, and coagulation factor XII. 313 37

Cell lines are valuable resources for the study of the malignancy and potential therapy of human breast cancer. A major problem with adapting fresh breast tumor specimens to grow in vitro is contamination by fibroblasts. Previously, we have reported a technique to overcome this problem (Nayak, S. K; Dillman, R. O. Clin. Biotechnol. 3:237-242; 1991). We have recently established two new breast cancer cell lines, HH315 and HH375, that were derived from abdominal and supraclavicular lymph node metastases from two patients. They were characterized by (1) growth kinetics; (2) staining with monoclonal antibodies (MoAbs) to cytokeratin-19, epithelial membrane antigen (EMA), anticarcinoembryonic antigen (CEA), breast cancer antigen 1 (BRST-1), breast cancer antigen 2 (BRST-2), Her2/neu, and p53; (3) expression of domains of urinary plasminogen activator (uPA), neural cell adhesion molecule (NCAM), and haptoglobin (Hp) (Harvey et al., 1997); and (4) karyotypic analysis. Growth kinetic studies showed that doubling times for both lines ranged from 48 to 96 h. These two cell lines were found to have characteristics of the metastatic breast cancer cells. Both lines stained positive with MoAbs to cytokeratin-19 and EMA, thus confirming their epithelial origin. They also strongly reacted with the pan-breast carcinoma MoAbs BRST-1 and BRST-2, and carcinoembryonic CEA MoAb. Both cell lines overexpressed the oncogene proteins Her2/neu and p53. The tumor cells were negative for estrogen and progesterone receptors. HH315 cells were poorly differentiated, whereas the HH375 cells exhibited adenocarcinoma morphology. Both cell lines showed intense cell surface and some cytoplasmic staining for uPA, NCAM, and Hp domains, which is a characteristic of malignant neoplasms (Harvey et al., 1997). The HH375 cell line showed two cell types, of which 60% were hyperdiploids with 60-70 chromosomes and 5-10 marker chromosomes. The remaining cells were polyploid with more than 200 chromosomes. Cell line HH315 consisted of only a polyploid population. These cell lines may be useful in breast cancer research.
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PMID:Characterization of cancer cell lines established from two human metastatic breast cancers. 1077 59

Following wounding, the surrounding fibroblasts migrate towards the clotted blood in the wounded space to form granulation tissue resulting in wound repair. One of the most abundant proteins in the wound is hemoglobin (Hb). The aim of the present study was to examine the effect of Hb on fibroblasts in producing components of the plasminogen-plasmin system which play an important role in wound healing. Human Hb A0 added to cultures of human fibroblasts elicited a dose-dependent increase in fibrinolytic activity. ELISA demonstrated an increased fibrinolytic activity due to increased urokinase-type plasminogen activator (uPA). An increase in tissue-type PA was also detected, while the type-I PA inhibitor level remained unaffected. Globin showed a similar effect, while hemin and protoporphyrin IX exerted no effect. The influence of Hb was quenched when haptoglobin was added. Although northern blot analysis revealed no difference in uPA transcripts between stimulated and non-stimulated cells, immunoprecipitation experiments confirmed an increased uPA synthesis in Hb- and globin-treated cells, suggesting that enhanced expression is achieved through translational regulation. These findings suggest a potential role for globin in modulating cellular functions during the process of wound healing.
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PMID:A novel function of extraerythrocytic hemoglobin: identification of globin as a stimulant of plasminogen activator biosynthesis in human fibroblasts. 1177 22

Anthrax is a zoonotic disease caused by Bacillus anthracis. The infection is associated with inflammation and sepsis, but little is known about the acute-phase response during disease and the nature of the bacterial factors causing it. In this study, we examined the levels of the acute-phase proteins (APPs) in comparative experiments using mice challenged with spores and a purified B. anthracis protease InhA as a possible factor mediating the response. A strong increase in the plasma levels of APPs such as haptoglobin and serum amyloid A was observed during infection. Protein and mRNA levels of plasminogen activator inhibitor (PAI)-1 in the liver were also increased concurrently with bacterial dissemination at 72 h post-infection. Similar effects were observed at 6 h post injection with InhA. Induction of hepatic transforming growth factor-beta1, a PAI-1 inducer, was also found in the liver of InhA-injected mice. PAI-1 elevation by InhA resulted in an increased level of urokinase-type plasminogen activator complex with PAI-1 and a decreased level of D-dimers indicating inhibition of blood fibrinolysis. These results reveal an acute liver response to anthrax infection and provide a plausible pathophysiological link between the host inflammatory response and the pro-thrombotic haemostatic imbalance in the course of disease through PAI-1 induction in the liver.
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PMID:Activation of plasminogen activator inhibitor implicates protease InhA in the acute-phase response to Bacillus anthracis infection. 1942 49

Ecotin is a bidentate, fold-specific inhibitor of mammalian serine-proteases produced by Escherichia coli. This molecule may be engineered to increase and/or change its affinity and specificity providing significant biotechnological potential. Since ecotin binds tightly to serine proteases of the trypsin fold, it may help to identify the role of these enzymes in different biological processes. In this work, we tested ecotin variants as an affinity purification reagent for identifying enzymes in samples of tumor progression and mammary gland involution. Initially, we used a commercial source of urokinase-type plasminogen activator (u-PA) that remained fully active after elution from an affinity column of the ecotin variant (M84R, M85R). We then successfully identified u-PA from more complex mixtures including lysates from a prostate cancer cell line and involuting mouse mammary glands. Interestingly, a membrane-type serine protease 1 was isolated from the Triton X-100-solubilized PC-3 cell lysates, and surprisingly, haptoglobin, a serine-protease homolog protein, was also identified in mammary gland lysates and in blood. Haptoglobin does not prevent ecotin inhibition of u-PA, but it may act as a carrier within blood when ecotin is used in vivo. Finally, this affinity purification matrix was also able to identify a thrombin-like enzyme from snake venom using an ecotin variant directed against thrombin. Overall, the ecotin variants acted as robust tools for the isolation and characterization of proteins with a trypsin fold. Thus, they may assist in the understanding of the role of these serine proteases and homologous proteins in different biological processes.
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PMID:Engineering ecotin for identifying proteins with a trypsin fold. 1972 73

We have established differentiated subclones from sodium butyrate-treated HT29 colon carcinoma cells. Two subclones, CIII and CVII, grew as tightly-compacted colonies and showed polarized confluent monolayers in vitro. CIII cells formed domes in vitro, a morphological characteristic of columnar absorptive epithelium. Besides these differentiated characteristics, CIII and CVII cells showed lower tumorigenicity than parental HT29 cells. Karyotypic analysis indicated that all cells retained chromosomes in the triploid range. However, modal chromosome numbers among 30 metaphases of each clone were concomitantly reduced from 71 (in HT29) to 68 (in CVII) or 67 (in CHI) with the differentiated phenotypes. Our preliminary karyotype analysis has suggested that the number of chromosomes 10q21-qter, 14q22-qter and 16q were decreased in both subclones. To confirm this, DNAs from these cells and another butyrate-induced subclone, CI-1, were analyzed with several DNA markers. Southern blot analysis indicated that parental HT29 cells were polymorphic for the BamHI and TaqI RFLPs detected by urokinase (7 kbp and 1.6 kbp) and D10S25 (2.5 kbp and 2.1 kbp) probes, respectively, both of which are located on chromosome band 10q. In CI-1 and CVII cells, allelic losses of urokinase (1.6 kbp) and D10S25 (2.5 kbp) were observed, respectively. Although both alleles of these markers were conserved in CIII cells, one allele of urokinase (7 kbp) and D10S25 (2.1 kbp) was less representative. Southern blot analysis using probes for Fos proto-oncogene, D14S20 marker type IV collagenase gene, haptoglobin gene located on chromosome bands 14q and 16q did not show any loss or rearrangement occurred in these subclones. Similarly, no loss or rearrangement was observed for the krev-1 gene on chromosome 1, whose number was not changed in either subclone. These findings indicate that in CI- 1, CIII, and CVII cells, the number of chromosome band 10q is decreased relative to HT29 cells. These deletions may be implicated in the morphological differentiation of HT29 cells treated with sodium butyrate.
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PMID:Chromosomal alterations in permanently differentiated ht29 colon-carcinoma cells induced with sodium-butyrate. 2157 45