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)

The promoter region of the potato proteinase inhibitor II (PI-II) gene was studied to identify cis-acting regulatory sequences involved in sugar response using transgenic tobacco plants. The 5' control region covering an 892 nucleotide sequence upstream from the cap site and a 32 nucleotide untranslated region of the PI-II promoter was able to activate a reporter chloramphenicol acetyltransferase (cat) gene by wounding or by incubating in a sugar-free medium. This wound response was further enhanced by sugar. Hexoses, disaccharides, and some trisaccharides were strong inducers whereas pentoses, deoxy sugars, sugar acids, TCA cycle intermediates, amino acids, and other carbohydrates had little effect on the promoter activity. Deletion of the sequence between -892 and -573 abolished the wound response but not the sugar response. An additional 5' deletion to -453 removed the sugar inducibility. Locations of the cis-acting regulatory elements were further elucidated by 3' deletion analysis. Deletion of the downstream region from -520 did not affect the wound or sugar response of the promoter. However, 3' deletion mutant -574 was unable to respond to sugar but did respond weakly to wounding. Further deletion to -624 abolished both responses. Therefore, it can be concluded that a wound response element is located in between -624 and -574 and that the response is further enhanced by a sugar response element located in the sequence between -573 and -520.
Plant Mol Biol 1991 Nov
PMID:Sugar response element enhances wound response of potato proteinase inhibitor II promoter in transgenic tobacco. 193 87

A rat brain extract, able to synthesize from UDP-Glc an alpha-1,4-glucan covalently bound to a protein in the absence of added primer is described. The compound formed is precipitable by dilute trichloroacetic acid (TCA). In the presence of glycogen, added as primer, this molecule is enlarged and is not precipitable by TCA. Unprimed and primed activities differ in several aspects, such as the behavior in the presence of some effectors, and the optimum pH. Umprimed and primed activities presented two pHs optima, both sharing only one. The proteoglucans synthesized under the different pHs gave different patterns after analysis under denaturing PAGE and the oligosaccharides synthesized on the protein backbone differ in the glucosyl length. It is concluded that also in rat brain, the initiation process of glycogen biosynthesis is mediated through the formation of a glycoprotein. Our present results showed that the step of the putative "Glycogen Initiator" proposed by use before, requires two enzymes UDPGlc-transglucosylating activities, Glycogen Initiator 1 and Glycogen Initiator 2, before Glycogen Synthase in the alpha-1,4-glucosidic linkages formation.
Cell Mol Biol 1991
PMID:A new enzymatic activity participating in the initiation of glycogen biosynthesis in rat brain. 193 16

We have delineated the region of yeast ribosomal protein L25 responsible for its specific binding to 26 S rRNA by a novel approach using in vitro synthesized, [35S]methionine-labeled fragments as well as point mutants of the L25 protein. The rRNA binding capacity of these mutant polypeptides was tested by incubation with an in vitro transcribed, biotinylated fragment of yeast 26 S rRNA that contains the complete L25 binding site. Protein-rRNA interaction was assayed by binding of the rRNA-r-protein complex to streptavidin-agarose followed either by analysis of the bound polypeptide by SDS/polyacrylamide gel electrophoresis or by precipitation with trichloroacetic acid. Our results show that the structural elements necessary and sufficient for specific interaction of L25 with 26 S rRNA are contained in the region bordered by amino acids 62 and 126. The remaining parts of the protein, in particular the C-terminal 16 residues, while not essential for binding, do enhance its affinity for 26 S rRNA. To test whether, as suggested by the results of the deletion experiments, the evolutionarily conserved sequence motif K120KAYVRL126 is involved in rRNA binding, we replaced the leucine residue at position 126 by either isoleucine or lysine. The first substitution did not affect binding. The second, however, completely abolished the specific rRNA binding capacity of the protein. Thus, Leu126, and possibly the whole conserved sequence motif, plays a key role in binding of L25 to 26 S rRNA.
J Mol Biol 1991 Mar 20
PMID:rRNA binding domain of yeast ribosomal protein L25. Identification of its borders and a key leucine residue. 201 Sep 15

To understand the molecular basis of mutation stimulated by deoxyribonucleotide pool imbalance, we studied a temperature-sensitive T4 phage gene 42 mutant (LB3), which specifies a thermolabile deoxycytidylate hydroxymethylase. Analysis of rII mutations, revertible to wild type along either GC-to-AT or AT-to-GC transition pathways, showed 8- to 80-fold stimulation of GC-to-AT mutations at a semi-permissive temperature (34 degrees C). One such marker, rII SN103, which showed the highest stimulation at 34 degrees C, was sequenced after amplification of the template by polymerase chain reaction. The mutant site in rII SN103 was identified at nucleotide position 265 from the rII B translational start as an AT-to-GC transition, which changes TCA to CCA. Sequence analysis of revertants and pseudorevertants generated at 34 degrees C showed that both cytosines within this triplet can undergo change to either thymine or adenine, consistent with the hypothesis that hydroxymethyldeoxycytidine triphosphate pools are depleted at replication sites. However, dNTP pool measurements in extracts of 34 degrees C cultures showed no significant deviations from values obtained at 30 degrees C, suggesting that pool imbalances occur only locally, close to replication forks. Our studies support the hypothesis that the mutator phenotype displayed by ts LB3 at semi-permissive temperature is a consequence of perturbation of the flow of nucleotide precursors into the DNA replication machinery. A putative localized depletion of hm-dCTP presumably enlarges effective dTTP/hm-dCTP and dATP/hm-dCTP pool ratios, resulting in the observed C-to-T transition and C-to-A transversion mutations.
Mol Gen Genet 1991 Apr
PMID:Analysis of mutagenesis induced by a thermolabile T4 phage deoxycytidylate hydroxymethylase suggests localized deoxyribonucleotide pool imbalance. 203 18

We have studied the relationship between lysosomes and lamellar bodies in alveolar type II (ATII) pneumocytes using a monoclonal antibody (anti-lgp-120) directed against a 120-kD rat lysosomal membrane glycoprotein and a polyclonal antibody (anti-SP-A) directed against rat surfactant protein A. The anti-lgp-120 precipitated a protein molecular mass of 120 kD from Triton cell lysates radiolabeled with [35S]methionine, and the anti-SP-A precipitated surfactant apoprotein A from the medium when analyzed under similar conditions. When ATII cells were cultured on Engelbreth-Holm-Swarm tumor basement membrane, and studied by indirect immunofluorescence, some structures seem to react with both antibodies, and others with only one. ATII cells cultured on plastic showed a major population of large vesicles that were labeled intensely with both antibodies, and a second population of vesicles that were labeled weakly and only with anti-SP-A. Analytical cell fractionation of freshly isolated ATII cells confirmed that lgp-120 was only present in structures containing the lysosomal matrix enzyme N-acetyl-beta-glucosaminidase. In contrast, SP-A was identified in two populations of vesicles with high phospholipid-to-protein ratios: one lacked N-acetyl-beta-glucosaminidase and lgp-120 and contained lamellar bodies; the other contained both lysosomal markers and a heterogeneous population of organelles that included multivesicular bodies, lamellar bodies, and lysosomes. Western blots of trichloroacetic acid precipitates of cell fractions identified proteins within the lysosomal compartment that reacted with anti-SP-A, but whose molecular mass was less than 28 kD. The results indicate that, in ATII cells, surfactant is located in two functionally distinct structures, one of which is probably involved in surfactant secretion, and the other, surfactant degradation. The techniques developed in this study should allow the role of these structures in the secretion and recycling of surfactant to be determined.
Am J Respir Cell Mol Biol 1991 Jun
PMID:The relationship between lamellar bodies and lysosomes in type II pneumocytes. 205 92

The N-glycan-processing inhibitors swainsonine (Sw) and deoxymannojirimycin (dMM) were used to study the influence of N-glycans on iodide organification in cultured porcine thyroid cells. Incubations with [125I]NaI were followed by determination of labeled trichloroacetic acid-insoluble material in culture media, follicular contents and cells. In controls, most of this material was in the follicular contents. With Sw and dMM, total acid-insoluble material was less than 10% of control. Iodide uptake was slightly inhibited and hydrogen peroxide release was not affected by inhibitors. Cell-surface thyroid peroxidase (TPO) activity, assayed by its ability to iodinate bovine serum albumin, was strongly inhibited. Pronase glycopeptide analysis indicated that with drugs the content in complex-type N-glycans was strongly decreased while that in hybrid or oligomannosidic type was increased. In conclusion, inhibition of N-glycan processing prevents iodide organification in cultured porcine thyroid cells by decreasing the recovery of cell-surface TPO activity.
Mol Cell Endocrinol 1990 Oct 22
PMID:Inhibition of N-glycan processing affects iodide organification in porcine thyroid cells. 214 33

A UGA suppressor derived from a glutamine tRNA gene of Escherichia coli K12 was isolated and characterized. Phages carrying the suppressor su+2UGA could be obtained only from a hybrid transducing phage, h80cI857psu+2oc, but not from the original transducing phage lambda cI857psu+2oc. By DNA sequence analysis, it was found that the su+2 UGA suppressor obtained has two mutations; one is in the anticodon (TTA----TCA), as expected, and the other (C----T) is at the 7th position from the 3' end of tRNA(2Gln). The significance of these mutations and the lethal effect on phage lambda of the increased amounts of UGA suppressor tRNAs are discussed.
Mol Gen Genet 1990 Sep
PMID:Mutant of the glutamine transfer RNA gene as UGA suppressor in Escherichia coli. 227 83

Estrogen-receptor complex activates the genes coding for the egg yolk protein precursor vitellogenin in hepatocytes of oviparous vertebrates, while oocyte vitellogenin genes are unresponsive to the hormone. Localization of [3H]steroid hormones (estradiol, progesterone, testosterone, and dexamethasone) was assayed in 10% trichloroacetic acid-precipitated dissected Xenopus oocytes (germinal vesicle vs. the rest of the oocyte). Whether hormones were introduced by incubation in the medium surrounding the oocytes or by injection of an equivalent amount into the oocyte cytoplasm, all hormones partitioned into the nucleus at equivalent levels (approximately 5%), reflecting that portion of the oocyte volume occupied by its nucleus. Therefore, intracellular receptors for these hormones were not detectable. Subsequently, we introduced a species-heterologous estrogen receptor into the Xenopus oocyte via a recombinant plasmid containing the coding sequence for the human estrogen receptor (HER) housed in a vector that ensures highly efficient transcription and translation of inserted sequences. HER synthesis was directed from injected plasmid (2 ng/oocyte germinal vesicle) as shown by [35S]methionine incorporation into newly synthesized proteins; however, vitellogenin was not synthesized under these conditions. When HER plasmid-injected oocytes were incubated in [3H]estradiol, they translocated to the nucleus 38% of the radiolabeled estradiol taken up by the cells, compared to 5% nuclear localization for vector-injected controls. Therefore, although the oocyte can readily transcribe and translate HER sequences as well as appropriately partition the completed protein in the nuclear compartment, the endogenous, potentially estrogen-responsive vitellogenin genes of the oocyte are not expressed.
Mol Endocrinol 1990 Apr
PMID:Expression and translocation of cloned human estrogen receptor in the Xenopus oocyte does not induce expression of the endogenous oocyte vitellogenin genes. 228 Jul 76

The effects of endotoxin or testosterone on the amount of transferrin 59Fe (or like protein) in the murine macrophages was investigated. The mouse peritoneal macrophages were laden with 59Fe tagged red cells following the injection of mice with either agent. After harvesting the cells, they were lysed and the transferrin iron was released with 40% trichloroacetic acid. The supernatant (extract transferrin iron) and the pellet (other iron proteins iron) were separated by centrifugation and their radioactivities counted. The results were expressed in percentage. The endotoxin group had a geometric mean of transferrin 59Fe of 0.14% compared to 0.28% for the control, p less than 0.001. The geometric mean for transferrin 59Fe of the testosterone treated group was 0.51% compared to 0.35% for the control, p less than 0.05. Therefore, the endotoxin seems to contract the transferrin pool whereas testosterone seems to expand it.
Mol Cell Biochem 1990 Jun 01
PMID:Modulators of macrophage transferrin or transferrin-like protein. 236 52

Bovine cumulus oocyte complexes (COCs) were isolated from antral ovarian follicles (4-8 mm). Immature COCs were classified into four categories, based on the homogeneity and clearness of the ooplasm and the transparency and compactness of the cumulus investment. In this study, the incorporation of TCA-precipitable 35S-methionine and the protein synthesis patterns of oocytes of these four categories were examined. Before maturation in vitro, similar incorporation rates and identical protein synthesis patterns were observed between oocytes of categories 1-3. Immature oocytes of category 4 showed reduced incorporation rates and exhibited aberrant protein synthesis patterns. After maturation in vitro, the patterns of category 4 oocytes were identical with the patterns of those in categories 1-3. The incorporation of 35S-methionine into in vitro matured oocytes was lower (P less than .001) in all categories. Based on these results, it is concluded that the initial classification of oocytes into four categories can be reduced to two categories.
Mol Reprod Dev 1990 Jul
PMID:Analysis of protein synthesis in morphologically classified bovine follicular oocytes before and after maturation in vitro. 237 75


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