Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Trypsin, phospholipase A2, lysolecithin or non-ionic detergent polyoxyethylene p-t-octyl phenol solutions were injected into the rat biliopancreatic duct. Histological and ultrastructural changes in the gland were studied 15 min and 3 h after the injections. The rough surfaced endoplasmic reticulum disintegrated in two ways: (1) the endoplasmic reticulum in the cell periphery was vesiculated but ribosomes were well preserved at 15 min, and (2) large, round membranous structures appeared in apical cytoplasm at 3 h. Zymogen granules disintegrated in the second type, which possibly represents autodigestion. Both types of injury lead ultimately to structureless necrosis. Lesions induced by phospholipase A2 and lysolecithin were identical. Trypsin-induced damage developed slowly and the two phases of endoplasmic reticulum disintegration were not sharply separable. Lesions caused by polyoxyethylene p-t-octyl phenol were variable at 15 min, but at 3 h the type 2 injury described above was observed. It was concluded that although the initial damage in pancreatic acinar cells may vary, necrotic changes are similar despite the injected material at the later time interval. During acute pancreatitis, the acinar cell necrosis is most probably due to the action of lysolecithin produced by the activation of phospholipase A2.
Virchows Arch B Cell Pathol Incl Mol Pathol 1982
PMID:Experimental pancreatitis in the rat. Light and electron microscopical observations on early pancreatic lesions induced by intraductal injection of trypsin, phospholipase A2, lysolecithin and non-ionic detergent. 612 35

cDNA synthesized on rabbit bone marrow erythroid cells pre-mRNA was cloned in bacterial plasmids. Cold phenol extracted pre-mRNA was a several times more effective template in the reaction of reverse transcription without oligo(dT) 10-primer than hot phenol extracted pre-mRNA. There was no yield increase of DNA-product on hot phenol extracted pre-mRNA in the reaction of reverse transcription with the oligo(dT)10-primer addition. The "hot phenol" poly (A)+-pre-mRNA was used to obtain the representative, full-sized cDNA. The double-stranded form of this cDNA, obtained with the help of DNA-polymerase I, was inserted into the PstI-site of pBR322 plasmid. About 25% E. coli JC5183 clones, transformed with this hybrid plasmid, were found to contain the globin sequences.
Mol Biol (Mosk)
PMID:[Synthesis and cloning of DNA, complementary to rabbit globin pre-mRNA]. 617 92

RNA extraction from mammalian tissue has been compared using the different deproteinizing agents: a) guanidine-HCl, b) guanidinium-thiocyanate, c) buffer-saturated phenol, or d) buffer-saturated phenol followed by a proteinase K digestion of the aqueous phase. Both solid tissues (first, second, and third trimester fetal bovine pancreas), and human white blood cell populations were studied. Degradation, as seen in citric acid-urea agarose gels, and the ability to serve as templates for cell-free protein synthesis were used as criteria to assess the efficiency of the different methods. We conclude that employing buffer-saturated phenol with proteinase K digestion is a superior method for consistent extraction of relatively undegraded RNA in quantitative amounts from mammalian tissue.
Mol Cell Biochem 1983
PMID:Efficient extraction of RNA from mammalian tissue. 619 12

Intermolecular duplexes among large nuclear RNAs, and between small nuclear RNA and heterogeneous nuclear RNA, were studied after isolation by a procedure that yielded protein-free RNA without the use of phenol or high salt. The bulk of the pulse-labeled RNA had a sedimentation coefficient greater than 45 S. After heating in 50% (v/v) formamide, it sedimented between the 18 S and 28 S regions of the sucrose gradient. Proof of the existence of interstrand duplexes prior to deproteinization was obtained by the introduction of interstrand cross-links using 4'-aminomethyl-4,5',8-trimethylpsoralen and u.v. irradiation. Thermal denaturation did not reduce the sedimentation coefficient of pulse-labeled RNA obtained from nuclei treated with this reagent and u.v. irradiated. Interstrand duplexes were observed among the non-polyadenylated RNA species as well as between polyadenylated and non-polyadenylated RNAs. beta-Globin mRNA but not beta-globin pre-mRNA also contained interstrand duplex regions. In this study, we were able to identify two distinct classes of polyadenylated nuclear RNA, which were differentiated with respect to whether or not they were associated with other RNA molecules. The first class was composed of poly(A)+ molecules that were free of interactions with other RNAs. beta-Globin pre-mRNA belongs to this class. The second class included poly(A)+ molecules that contained interstrand duplexes. beta-Globin mRNA is involved in this kind of interaction. In addition, hybrids between small nuclear RNAs and heterogeneous nuclear RNA were isolated. These hybrids were formed with all the U-rich species, 4.5 S, 4.5 SI and a novel species designated W. Approximately equal numbers of hybrids were formed by species U1a, U1b, U2, U6 and W; however, species U4 and U5 were significantly under-represented. Most of these hybrids were found to be associated stably with non-polyadenylated RNA. These observations demonstrated for the first time that small nuclear RNA-heterogeneous nuclear RNA hybrids can be isolated without crosslinking, and that proteins are not necessary to stabilize the complexes. However, not all molecules of a given small nuclear RNA species are involved in the formation of these hybrids. The distribution of a given small nuclear RNA species between the free and bound state does not reflect the stability of the complex in vitro but rather the abundance of complementary sequences in the heterogeneous nuclear RNA.(ABSTRACT TRUNCATED AT 400 WORDS)
J Mol Biol 1984 Aug 05
PMID:Interstrand duplexes in Friend erythroleukemia nuclear RNA. The interaction of non-polyadenylated nuclear RNA with polyadenylated nuclear RNA and with small nuclear RNAs. 620 60

The majority of the DNA prepared from tailless capsids of bacteriophage P2 by the phenol extraction procedure consists of monomeric rings that have their cohesive ends joined. Electron microscopic and ultracentrifugal studies indicate that these molecules have a complex structure that is topologically knotted; they have a more compact appearance and a higher sedimentation coefficient when compared with regular nicked P2 DNA rings. Linearization of these rings by thermal dissociation or repair of the cohesive ends by DNA polymerase I in the presence of all four deoxynucleoside triphosphates gives molecules that are indistinguishable from normal P2 DNA that has been similarly treated. The knotted nature of the majority of P2 head DNA is further supported by analyzing the products when these molecules are treated with ligase and the ligase-treated molecules are subsequently nicked randomly with DNase I. The data are consistent with the notion that, if such a molecule is first converted to a form that contains only one single-chain scission per molecule, strand separation gives a linear strand and a highly knotted single-stranded ring. The results suggest that the DNA packaged in tailless P2 capsids is arranged in a way that leads to the formation of a complex knot when the ends join. In an intact phage particle, the anchoring of one terminus of the DNA to the head-proximal end of the tail [Chattoraj, D. K. & Inman, R. B. (1974) J. Mol. Biol. 87, 11-22] presumably diminishes or prevents this kind of joining. The novel knotted DNA can be used to assay type II DNA topoisomerases that break and rejoin DNA in a double-stranded fashion.
 ...
PMID:Knotted DNA from bacteriophage capsids. 627 6

Polypeptides co-purifying with DNA in alkali are covalently bound to DNA. DNA purified by treatment with alkali, sodium dodecyl sulphate and phenol absorbed 125I under conditions designed to radioiodinate exclusively tyrosine and histidine in peptides. A significant amount of the absorbed 125I remained associated with DNA during treatment with phenol as well as during precipitation with ethanol from neutral and alkaline solutions. However, after prolonged digestion with proteinase K, most of the radiolabelled material could be removed from 125I-treated DNA. Further treatment with a second protease (Pronase) released no larger fraction of the 125I label. The residual radiolabelled material could be precipitated together with DNA by ethanol and it remained associated with DNA also in the presence of alkali (95 degrees C), acid (37 degrees C) and hydroxylamine (37 degrees C). In contrast, radiolabelled peptides were released from DNA by treatment with hot piperidine (10% at 95 degrees C) and by agents that hydrolyse peptides and modify DNA, e.g. strong acid (95 degrees C) and formic acid/diphenylamine. The radiolabelled peptides, once released from DNA by these chemical methods, could be further cleaved by Pronase. This shows that the residual DNA/peptide complex isolated after prolonged protease digestion is protease-resistant unless it is cleaved or otherwise modified by harsh chemical treatment. The linking groups between deoxynucleotides and the radiolabelled residual peptides could be isolated by digestion of DNA in the DNA/peptide complex. Radiolabelled peptides could be released from this linking group material by phosphodiesterases, indicating the involvement of phosphodiesters in the linking groups.
J Mol Biol 1983 Feb 25
PMID:Phosphodiester bonds between polypeptides and chromosomal DNA. 630 72

Upon superinfection of immune (lysogenic) cells with bacteriophage Mu, a form of Mu DNA accumulates that sediments about twice as fast as the linear phage DNA marker in neutral sucrose gradients. This form is also detected upon infection of sensitive cells with Mu. We have purified it and examined its physical nature. Under the electron microscope it appears circular and supertwisted. Upon treatment with Pronase, phenol or sodium dodecyl sulfate, however, it is converted to a linear Mu-length form, indicating that the circle is not covalently closed. The linear DNA still has heterogeneous host sequences at its termini. The circular DNA is resistant to the action of Escherichia coli exonuclease III and T7 exonuclease, but becomes sensitive to these nucleases after treatment with Pronase showing the presence of a protein that binds non-covalently to the ends of the DNA to circularize it as well as protect it from digestion with exonucleases. The complex is resistant to high salt (up to 6 M-NaCl) but can undergo transitions between forms that are partially open, open circular, linear and circular dimers and trimers. Examination of DNA from mature phage particles reveals that a circular DNA species is present in at least 0.1 to 1% of the population. The purified complex is extremely efficient in transfection of E. coli spheroplasts. We estimate the molecular weight of the protein in this DNA-protein complex to be approximately 64,000, and suggest that this complex might represent the integrative precursor of infecting Mu DNA.
J Mol Biol 1983 Jun 25
PMID:Infecting bacteriophage mu DNA forms a circular DNA-protein complex. 630 60

Inclusion of calf thymus DNA during microsomal benzo[a]pyrene (BP) metabolism increases product formation by decreasing the accessibility of microsomal enzymes to inhibitory BP quinones. The relief of product inhibition of BP metabolism, the stimulation of the formation of BP 7,8-dihydrodiol-9,10-oxides (DE), and the corresponding DNA adducts were all dependent to varying extents on DNA concentration. The role of BP quinones was evidenced by effects of DNA on all aspects of quinone reactivity: (a) inhibition of microsomal reduction of quinones, (b) inhibition of quinone glucuronidation, (c) inhibition of quinone monooxygenation, (d) a substantial reduction of the inhibition of BP metabolism and diol epoxide (DE) formation by added BP 6,12-quinone, and (e) a stimulation of BP metabolism even though quinine levels were also increased. DNA inhibited the reduction of 1,6- and 3,6-quinone to a similar degree under both oxygen-depleted and aerobic conditions. Other effects of DNA were very selective; glucuronidation of added 1,6- and 6,12-quinone was inhibited less than glucuronidation of 3,6-quinone (35% and 50% versus over 80%). However, monooxygenation of 3,6-quinone was not inhibited, whereas monooxygenation of 1,6-quinone was reduced by 60-70%. There was no measurable monooxygenation of 6,12-quinone. This specificity may indicate that DNA exerts its effect not simply by sequestering BP quinones. The interaction with DNA produced a distinct 25-nm red shift in the visible spectra of 1,6- and 3,6-quinone, while the change in the 6,12-quinone spectrum was less pronounced. RNA induced a similar red shift in the 1,6-quinone spectrum. Spectral measurements indicated binding of one molecule of 1,6-quinone per 50 DNA base pairs, while binding to RNA was 10-fold less extensive. The binding of 1,6-quinone to DNA was decreased by Mg2+, suggesting that 1,6-quinone binds by intercalation. DNA perturbs BP metabolism in a second way by increasing the ratio of 9-phenol to 9,10-dihydrodiol 4-fold. This is probably due to a DNA-catalyzed rearrangement of 9,10-oxide to 9-phenol. This effect contributes substantially to the greater sensitivity of the formation of 9-phenol 4,5-oxide-DNA adducts to the DNA concentration. It is evident from these data that, in addition to binding carcinogens covalently, DNA can affect the kinetics and product distribution of carcinogen metabolism. The high capacity of DNA to sequester BP quinones from cellular membranes is likely to be associated with additional DNA damage which may contribute to carcinogenesis.
Mol Pharmacol 1983 May
PMID:Modulation of microsomal benzo[a]pyrene metabolism by DNA. 630 33

The oxidation of benzidine, a carcinogenic aromatic amine, by H2O2 is catalyzed by horseradish peroxidase or lactoperoxidase. The resulting cation free radical is moderately stable at pH 5.0, and was identified by electron spin resonance spectroscopy. Two-electron oxidation yields the benzidine di-imine. This species reacts with phenol or catechol derivatives to give colored adducts. Monoacetylbenzidine is a relatively poor peroxidase substrate, and the biological implications of this difference are discussed.
Mol Pharmacol 1983 May
PMID:An electron spin resonance study of the activation of benzidine by peroxidases. 630 34

The interrelationship between adrenal steroidogenesis and polycyclic aromatic hydrocarbon metabolism has been examined in cultured bovine adrenal cortical (BAC) cells. Adrenocorticotropin (ACTH) selectively induced steroidogenic cytochrome P-450-dependent enzyme activities from BAC cell cultures. In the presence of 10(-7) M ACTH, steroid production requiring 17 alpha-hydroxylation (cortisol + androgens) was increased 5-fold over the formation of 17- deoxysteroids (corticosterone). The effect of 10 microns benz[a]anthracene on steroidogenesis was characterized by suppression of both steroid 17 alpha-hydroxylation (90%) and total steroidogenesis (50%), with a concomitant rise in 17- deoxysteroid formation. The order of stimulation of steroidogenic enzyme activities by ACTH (17 alpha-hydroxylase greater than side chain cleavage greater than 21-hydroxylase) paralleled the order of suppression by benz[a]anthracene. BAC cell cultures incubated with Su-10603, a specific 17 alpha-hydroxylase inhibitor, exhibited similar changes in the pattern of steroidogenesis, as did benz[a]anthracene-treated cells, suggesting that benz[a] anthracene also inhibits steroidogenesis as an inhibitor of 17 alpha-hydroxylase. In addition, benz[a]anthracene induced benzo[a]pyrene metabolism 4- to 6-fold over control levels in these cells. The profile of benzo[a]pyrene metabolites revealed predominantly water-soluble products (nonhydrolyzable greater than sulfates greater than glucuronides), 9,10- monooxygenation products, and 3-phenol. ACTH (10(-7) M) and 0.5 mM cyclic AMP each decreased benzo[a]pyrene metabolism by more than 50%. Both benz[a]anthracene-induced and uninduced benzo[a]- pyrene metabolism were equally reduced in response to ACTH and cyclic AMP. In the presence of 0.2 mM aminoglutethimide, which completely inhibited steroidogenesis, ACTH decreased benz[a]anthracene induction of benzo[a]pyrene metabolism to the same extent as ACTH treatment alone. It is concluded that the suppression of benzo[a]pyrene metabolism by ACTH is mediated by cyclic AMP and does not involve steroids generated in response to ACTH. These studies demonstrate that cytochrome P-450 isozymes involved in steroidogenesis and polycyclic aromatic hydrocarbon metabolism are regulated, in opposing directions, by ACTH.
Mol Pharmacol 1984 May
PMID:The interrelationship of polycyclic hydrocarbon metabolism and steroidogenesis in primary cultures of bovine adrenal cortical cells. 632 66


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