Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

PDC-109, a protein of unknown function, is a major component of bovine seminal plasma. Using a computer program designed to detect evolutionary relationships between proteins, I find that the PDC-109 protein is similar to the gelatin-binding domain of bovine fibronectin and part of a kringle domain of human tissue-type plasminogen activator (t-PA). The computer-based comparison of the amino acid sequence of PDC-109 with that of the gelatin-binding domain of fibronectin and part of the second kringle domain of t-PA yields scores that are 15.5 standard deviations and 7.8 standard deviations higher, respectively, than were obtained with a comparison of randomized sequences of these proteins. The probability (p) of getting these scores by chance is less than 10(-50) and 3 X 10(-15), respectively. The similarity between the amino acid sequences of PDC-109 and the gelatin-binding domain in fibronectin and the kringle of t-PA suggests some approaches for identifying the functions of PDC-109. Both t-PA and the gelatin-binding domain of fibronectin have adhesive functions, and the gelatin-binding domain promotes viral transformation of fibroblasts in culture. These functions may be associated with the PDC-109 protein.
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PMID:The PDC-109 protein from bovine seminal plasma is similar to the gelatin-binding domain of bovine fibronectin and a kringle domain of human tissue-type plasminogen activator. 404 Jul 57

A genomic clone carrying the human tissue-type plasminogen activator (t-PA) gene was isolated from a cosmid library, and the gene structure was elucidated by restriction mapping, Southern blotting, and DNA sequencing. The cosmid contained all the coding parts of the mRNA, except for the first 58 bases in the 5' end of the mRNA, and had a total length of greater than 20 kilobases. It was separated into at least 14 exons by at least 13 introns, and the exons seemed to code for structural or functional domains. Thus, the signal peptide, the propeptide, and the domains of the heavy chain, including the regions homologous to growth factors, and to the "finger" structure of fibronectin, are all encoded by separate exons. In addition, the two kringle regions of t-PA were both coded for by two exons and were cleaved by introns at identical positions. The region coding for the light chain, comprising the serine protease part of the molecule was split by four introns, revealing a gene organization similar to other serine proteases.
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PMID:The structure of the human tissue-type plasminogen activator gene: correlation of intron and exon structures to functional and structural domains. 608 98

Chicken embryo cells infected with partial transformation mutants of Rous sarcoma virus were tested for tumor-forming ability in chickens and in nude mice. Cells transformed by each of these partial transformation mutants display different combinations of transformation parameters. They therefore present a potentially favorable system for analyzing which properties of transformed cells are necessary for tumor formation. We found that the relative tumorigenicity of the virus mutants was generally similar in chickens and in nude mice, except that certain temperature-conditional mutants appeared to be sensitive to the differences in body temperature of the two experimental animals. (The body temperature of nude mice is 4 to 5 degrees C lower than that of chickens). Thus, the nude mouse appears to be a suitable system for testing the tumorigenicity of transformed chicken cells. Because mice are nonpermissive for Rous sarcoma virus infection and replication, it was possible to recover the transformed chicken cells from the tumors in this host and to determine what phenotypic changes they had undergone during tumor development. We also examined the relationship between various cellular properties of the virus-infected chicken cells in vitro and their tumorigenicity in nude mice. The combined results of these two studies indicated that anchorage independence and plasminogen activator production were highly correlated with the tumor-forming ability of these cells, whereas loss of fibronectin did not correlate with tumorigenicity. Furthermore, the inability of the least tumorigenic virus mutant to stimulate the phosphorylation of a 36,000-Mr target of pp60src raises the possibility that the 36,000-Mr protein plays a role in tumor formation.
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PMID:Tumorigenicity of partial transformation mutants of Rous sarcoma virus. 617 71

Treatment of F9 teratocarcinoma cells with all trans retinoic acid (RA) causes them to differentiate into two or three morphologically distinct cell types. Whereas the majority of these retinoid-derived cells exhibit properties resembling parietal endoderm, a small percentage of this differentiated cell population manifests properties distinct from the parietal endoderm cell type. The isolation and partial characterization of such a non-parietal endoderm cell line (Dif 5) derived from F9 cells following prolonged (44 days) exposure to 1 microM retinoic acid are described. Unlike the retinoid-induced parietal endoderm-like cell population, which exhibits a dramatic, characteristic morphological change upon treatment with 8-bromo cAMP, Dif 5 cells do not show any morphological change with exposure to this cAMP analog. Dif 5 cells synthesize and deposit an extracellular matrix consisting of several components of Reichert's membrane (fibronectin, laminin, and type IV collagen). This new cell line does not synthesize alpha-fetoprotein but does secrete plasminogen activator. An interesting property of these cells is their ability to grow in the absence of serum or other hormonal supplements. Yet the Dif 5 cells do exhibit density-dependent inhibition of growth. Unlike the parent F9 cells or parietal yolk sac (PYS-2) cells, these cells do possess specific cell surface receptors for epidermal growth factor (EGF). The growth-arrested Dif 5 cells can be reinitiated to proliferate by the addition of fetal calf serum (FCS) or EGF. The properties of Dif 5 cells determined fail to fulfill all the characteristics described for either parietal or visceral endodermal cells. This raises the possibility that Dif 5 cells might represent an endodermal cell type which is intermediate in differentiation to either parietal or visceral endoderm but which lacks the biochemical signal to complete this stage of differentiation. This new Dif 5 cell line should be of considerable value in studying the modulation of growth requirements and extracellular matrix formation during early embryonic development.
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PMID:A new differentiated cell line (Dif 5) derived by retinoic acid treatment of F9 teratocarcinoma cells capable of extracellular matrix production and growth in the absence of serum. 619 79

Although ulceration of the corneal stroma after alkali burns is known to be correlated with persistent epithelial defects, the relationship between a defect and the mediators thought to contribute to stromal destruction (plasminogen activator, plasmin, collagenase) has not been understood. This report demonstrates that fibrin and fibronectin appear on the stromal surface after an alkali burn, and that those substratum, matrix components disappear in correlation with the appearance of plasminogen activator on the stromal surface, re-surfacing by the epithelium and a persistent epithelial defect. The facts that epithelium releases plasminogen activator and that plasmin, generated from plasminogen by an activator, can degrade both fibrin and fibronectin, as well as the laminin component of the subepithelial basement membrane, would suggest that the plasminogen activator-plasmin system effect degradation of those macromolecules, thus initiating the events that lead to eventual, frank stromal ulceration. It is hypothesized that stromal ulceration is initiated by the chronic secretion from an epithelium with a persistent defect of a protease (plasminogen activator) involved in wound healing.
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PMID:Ulceration is correlated with degradation of fibrin and fibronectin at the corneal surface. 622 46

This paper reports the growth and differentiation of the mouse embryonal carcinoma cell line F9 in completely defined culture media. The defined growth medium, referred to as EM-3, contains plasma fibronectin, insulin, and transferrin in place of serum. F9 cells cultured in EM-3 for over 15 generations retain their ability to form tumors and to differentiate. Fibronectin is essential for the attachment of F9 cells in defined media and its effect can be blocked with affinity-purified anti-fibronectin. When retinoic acid was added to EM-3, the F9 cells differentiated. The majority of the the newly formed cells differed from patient F9 cell two major respects: (i) they were morphologically different; and (ii) they secreted plasminogen activator, and the secretion was stimulated by dibutyrlyl adenosine cyclic monophosphate.
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PMID:Growth and differentiation of embryonal carcinoma cell line F9 in defined media. 624 61

The effect of retinoic acid on the synthesis and degradation of basement membrane components by endoderm cells derived from mouse embryonal carcinoma (EC) cells was studied in a serum-free, defined medium. By immunofluorescence these cells accumulate type IV collagen, laminin, and fibronectin after growth in media containing epidermal growth factor (EGF), fibroblast growth factor (FGF), insulin, transferrin, and Pedersen fetuin. Collagen accounted for 2 to 4% of the newly synthesized proteins, of which 90% were found in the culture media. This collagen was identified as Pro-type IV be gel electrophoresis and enzymatic susceptibility. The EC cells preferentially attached to type IV collagen in vitro and such attachment was mediated by laminin. Treatment of EC cells with retinoic acid caused an increased accumulation of collagen (10 to 15% of secreted proteins) and also stimulated the elaboration of latent protease which degraded laminin and type IV collagen. The laminin-degrading activity was plasminogen dependent. The type IV collagen-degrading activity was a metal protease which could be activated by trypsin or plasmin. It is likely that at least part of the laminin degrading activity is plasmin (mediated through plasminogen activator), since highly purified plasmin is shown to degrade native laminin.
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PMID:Stimulation of retinoic acid of synthesis and turnover of basement membrane in mouse embryonal carcinoma-derived endoderm cells. 628 41

We have isolated and characterized mutants of Rous sarcoma virus which induce some parameters of transformation but fail to fully induce other parameters. We believe these mutants code for a pp60src which phosphorylates some targets well but phosphorylates others poorly. Using these mutants, we examined the phosphorylation of a 36,000 Mr protein which is phosphorylated on a tyrosine in cells transformed by Rous sarcoma virus, in an attempt to correlate this phosphorylation with the expression of specific transformation parameters. We found that phosphorylation of the 36,000 Mr protein was neither necessary nor sufficient for loss of fibronectin or for loss of density-dependent inhibition of growth. Phosphorylation of the protein was not sufficient for morphological alterations, increased hexose transport, or loss of adhesiveness. For the parameters measured, the best correlation was with increased plasminogen activator. In addition, it is noteworthy that cells infected with the mutant CU2 displayed low levels of phosphorylation of the 36,000 Mr protein and also were deficient in anchorage-independent growth and tumorigenicity, raising the possibility that the phosphorylation of the 35,000 Mr protein may be required for malignant growth properties.
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PMID:Phosphorylation of a 36,000 Mr cellular protein in cells infected with partial transformation mutants of rous sarcoma virus. 628 26

Epithelial-like chondrocytes obtained from chick embryo were transformed with Rous sarcoma virus. Cellular transformation was monitored looking at the morphology change, the cell growth, and the expression of plasminogen activator. Analysis on polyacrylamide gel of intracellular and secreted proteins showed: 1) a disappearance of the specific products of differentiated chondrocytes; 2) a switch in the collagen synthesis from the type II, the chondrocyte-specific type, to the type I, characteristic of fibroblasts and other cells of mesenchymal origin; 3) an enhancement of fibronectin synthesis. Analysis of the proteins from chondrocytes infected with Rous-associated virus 1, a virus unable to induce cell transformation in vitro, indicated that the altered expression of the differentiated proteins in Rous sarcoma virus-infected chondrocytes depended upon the action of src gene product.
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PMID:The culture of chick embryo chondrocytes and the control of their differentiated functions in vitro. Transformation by rous sarcoma virus induces a switch in the collagen type synthesis and enhances fibronectin expression. 630 82

Induction of the neutral proteinase, collagenase, is a marker for a specific switch in gene expression observed in rabbit synovial fibroblasts. A variety of agents, including 12-O-tetradecanoylphorbol-13-acetate, cytochalasins B and D, trypsin, chymotrypsin, poly(2-hydroxyethylmethacrylate), and trifluoperazine induced this change in gene expression. Induction of collagenase by these agents was always correlated with a marked alteration in cell morphology, although the cells remained adherent to the culture dishes. The amount of collagenase induced was positively correlated with the degree of shape change produced by a given concentration and, to some extent, with the duration of treatment. Altered cell morphology was required only during the first few hours of treatment with inducing agents; after this time collagenase synthesis continued for up to 6 d even when agents were removed and normal flattened cell morphology was regained. All agents that altered cell morphology also produced a characteristic switch in protein secretion phenotype, characterized by the induction of procollagenase (Mr 53,000 and 57,000) and a neutral metalloproteinase (Mr 51,000), which accounted for approximately 25% and 15% of the protein secreted, respectively. Secretion of another neutral proteinase, plasminogen activator, did not correlate with increased collagenase secretion. In contrast, synthesis and secretion of a number of other polypeptides, including the extracellular matrix proteins, collagen and fibronectin, were concomitantly decreased. That changes in cell shape correlated with a program of gene expression manifested by both degradation and synthesis of extracellular macromolecules may have broad implications in development, repair, and pathologic conditions.
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PMID:Changes in cell shape correlate with collagenase gene expression in rabbit synovial fibroblasts. 632 18


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