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 binding properties of [3H]1,25-dihydroxyvitamin D3 (1,25(OH)2D3) to 1,25(OH)2D3 receptor in mouse osteoblastic MC3T3-E1 cells and the affinity of 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3 (ST-630) were examined. Sucrose density gradient experiments demonstrated that [3H]1,25(OH)2D3 bound to the 6S macromolecule in the cytosol of MC3T3-E1 cells at 4 degrees C. The inhibitory effect of 1,25(OH)2D3 was compared with that of ST-630. However, at 30 degrees C, only the 3.7S macromolecule was labeled, and 1,25(OH)2D3 and ST-630 demonstrated similar affinity for the 3.7S macromolecule. Under the lower temperature condition, the cytosol from MC3T3-E1 cells showed one binding site for [3H]1,25(OH)2D3 with Kd of 0.31 nM and Bmax of 13.0 fmol/mg protein, respectively. Furthermore, from the competitive binding experiments at 4 degrees C, the affinity of ST-630 was 6.4-fold lower than that of 1,25(OH)2D3. These results suggest that the 6S macromolecule formed at the lower temperature in MC3T3-E1 cells has a property of 1,25(OH)2D3 receptor, but ST-630 has a higher affinity for 3.7S macromolecule and it may be comparable to 1,25(OH)2D3.
Res Commun Mol Pathol Pharmacol 1994 Jul
PMID:Temperature-dependent alteration of 1,25-dihydroxy-vitamin D3 receptor macromolecules in MC3T3-E1 cells: affinity of hexafluoro analog of 1,25-dihydroxyvitamin D3, ST-630, for these forms. 795 92

Various chimaeric promoter regions coupled to the uidA beta-glucuronidase gene were evaluated for transient expression strength following electroporation into sugar-cane (monocot) and carrot (dicot) protoplasts. Multiple enhancer elements increased expression in sugar-cane, by up to 400-fold for the artificial Emu promoter relative to the CaMV 35S promoter. The relative expression strengths of promoters varied substantially between the species. Sugar-cane also differed in some respects from previously tested species in the family Poaceae. For example, in sugar-cane the nopaline synthase and CaMV 35S promoters were of equivalent strength, and insertion of Adh1 intron 1 into the 5' transcribed region decreased expression strength.
Plant Mol Biol 1993 Nov
PMID:Effects of promoter, intron and enhancer elements on transient gene expression in sugar-cane and carrot protoplasts. 821 94

Tetraploid potato clones, transgenic for the rolC gene of Agrobacterium rhizogenes under control of the light-inducible ribulose bisphosphate carboxylase small subunit promoter (rbcS-rolC), were compared, with respect to yield attributes and tuber carbohydrates, with transformed and untransformed controls and with 35S-rolC transgenic potato plants. In rbcS-rolC plants, the expression of the rolC gene was located mainly in leaves, while in 35S-rolC plant transcripts were detected as well in shoots and roots. Phenotypically, rbcS-rolC transgenic plants were found to be slightly reduced in plant size with a few more tillers than control plants. Photosynthetic rate and chlorophyll content were significantly lower in all rolC transgenic plants irrespective of the type of construct used. Tuber yield was not significantly different between controls and rbcS-rolC transgenic plants, but was reduced in the 35S-rolC transformants. Sucrose level was unchanged in all rolC clones investigated, whereas fructose content was significantly enhanced in 35S-rolC transformants, but not in the plants expressing the rolC gene in aerial plant parts only. In both types of rolC transgenic plants, glucose content was lower than in controls, resulting in a significant reduction of reducing sugar in tubers. The results suggest a hormonal influence on the carbohydrate composition of potato tubers.
Plant Mol Biol 1993 Nov
PMID:Constitutive or light-regulated expression of the rolC gene in transgenic potato plants has different effects on yield attributes and tuber carbohydrate composition. 825 28

Effects of feeding sucrose rich diet supplemented with and without the insulinmimetic agent vanadate for a period of six weeks were studied in rats. Sucrose diet caused hypertriglyceridemia (140% increase), hyperinsulinemia (120% increase) and significant elevations in the levels of glucose (p < 0.001) and cholesterol (p < 0.05) in plasma as compared to control starch fed rats. Activities of hepatic lipogenic enzymes, ATP-citrate lyase, glucose 6-phosphate dehydrogenase and malic enzyme increased by 100-150% as a result of sucrose feeding. However, glycogen content and the activities of glycogen synthase and phosphorylase in liver remained unaltered in these animals. The plasma levels of triacylglycerols and insulin in the rats fed on vanadate supplemented sucrose diet were 65% and 85% less, respectively as compared to rats on sucrose diet without vanadate. The concentrations of glucose and cholesterol in plasma and the activities of lipogenic enzymes in liver did not show any elevation in sucrose fed rats when supplemented with vanadate. These data indicate that the sucrose diet-induced metabolic aberrations can be prevented by the insulin-mimetic agent, vanadate.
Mol Cell Biochem 1993 May 12
PMID:Effects of vanadate administration on the high sucrose diet-induced aberrations in normal rats. 835 Aug 66

The insulin-like effects of vanadate were compared in streptozotocin-induced diabetic rats fed on high starch control and high sucrose diets for a period of six weeks. Diabetic rats in both diet groups were characterized by hypoinsulinemia, hyperglycemia (6.8-7.0 fold increase) and significant decreases (p < 0.001) in the activities of glycogen synthase, phosphorylase and lipogenic enzymes, ATP-citrate lyase, glucose 6-phosphate dehydrogenase and malic enzyme in liver. There were no diet-dependent differences in these abnormalities. However, the insulin-mimetic agent vanadate was more effective in diabetic rats fed sucrose diet as compared to animals fed control starch diet. Vanadate administration resulted in 30% and 64% decreases in plasma glucose levels in diabetic rats fed control and sucrose diets, respectively. The activities of glycogen synthase (active) and phosphorylase (active and total) were restored significantly by vanadate in control (p < 0.05-0.01) and sucrose (p < 0.001) diets fed diabetic rats. This insulin-mimetic agent increased the activities of hepatic lipogenic enzymes in control diet fed rats to 38-47% of normal levels whereas in sucrose fed group it completely restored the activities. Sucrose diet caused a distinct effect on the plasma levels of triacylglycerol (4-fold increase) and apolipoprotein B (2.8-fold increase) in diabetic rats and vanadate supplementation decreased their levels by 65-75%. These data indicate that vanadate exerts insulin-like effects in diabetic rats more effectively in sucrose fed group than the animals fed control diet. In addition, vanadate also prevents sucrose-induced hypertriglyceridemia.
Mol Cell Biochem 1993 May 12
PMID:Effects of high sucrose diet on insulin-like effects of vanadate in diabetic rats. 835 Aug 67

The transforming protein of polyomavirus, middle T antigen, is associated with cellular membranes. We have examined the subcellular location of the middle T antigen in two different cell types by fractionation and detergent phase partitioning. Middle T antigen expressed in human cells by a recombinant adenovirus was detected primarily in the membrane skeleton. Sucrose gradient fractionation revealed that the middle T antigen was associated with complexes with molecular weights of 500,000 to 1,000,000. Several markers for cytoskeleton cofractionate with these complexes, including actin, tubulin, and vimentin. Electron micrographs of membrane skeleton prepared from cells expressing middle T antigen demonstrated that this material contained primarily fibrous structures and was clearly devoid of bilayer membranes. These structures were distinct from the filamentous structures observed in fractions enriched for cytoskeleton. Consistent with a role for membrane skeleton localization in transformation, middle T antigen was detected exclusively in fractions enriched for membrane skeleton in middle T antigen-transformed Rat-2 cells. Our results may resolve the apparent difference between middle T antigen localization as determined by immunomicroscopy and that determined by subcellular fractionation.
Mol Cell Biol 1993 Aug
PMID:Evidence that the middle T antigen of polyomavirus interacts with the membrane skeleton. 839 36

Expression of beta interferon (IFN-beta) is transiently induced when Namalwa B cells (Burkitt lymphoma cell line) are infected by Sendai virus. In this study, we found that an elongation of the IFN-beta mRNA could be detected in virus-infected cells and that such a modification was not observed when the IFN-beta transcript was induced by a nonviral agent, poly(I-C). Treatment of the cells with a transcriptional inhibitor (actinomycin D or 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole) resulted in further elongation of the transcript. Characterization of the elongated IFN-beta transcript by primer extension and RNase H treatment showed that the modification was a result of an elongated poly(A) tail of up to 400 nucleotides. We conclude that the poly(A) tail elongation of the IFN-beta transcript is associated with the viral infection. Furthermore, the presence of the elongated IFN-beta transcript correlated with a decrease of IFN-beta protein in the medium and in cell extracts. Sucrose gradient analysis of cytoplasmic extracts showed that IFN-beta transcripts with elongated poly(A) tails were found in the nonpolysomal fractions, whereas the shorter transcripts could be detected in both polysomal and nonpolysomal fractions. A longer form of the IFN-beta mRNA was also found in the nonpolysomal fractions of cells not treated with transcriptional inhibitors. Thus, the observed regulation of IFN-beta mRNA is not entirely dependent on the inhibition of transcription. To our knowledge, this study provides the first example of a poly(A) tail elongation in somatic cells that negatively influences gene expression in vivo.
Mol Cell Biol 1996 Feb
PMID:Repression of beta interferon gene expression in virus-infected cells is correlated with a poly(A) tail elongation. 855 72

Cultivated sugarcane clones (Saccharum spp., 2n=100 to 130) are derived from complex interspecific hybridizations between the species S. officinarum and S. spontaneum. Using comparative genomic DNA in situ hybridization, we demonstrated that it is possible to distinguish the chromosomes contributed by these two species in an interspecific F1 hybrid and a cultivated clone, R570. In the interspecific F1 studied, we observed n + n transmission of the parental chromosomes instead of the peculiar 2n + n transmission usually described in such crosses. Among the chromosomes of cultivar R570 (2n = 107-115) about 10% were identified as originating from S. spontaneum and about 10% were identified as recombinant chromosomes between the two species S. officinarum and S. spontaneum. This demonstrated for the first time the occurrence of recombination between the chromosomes of these two species. The rDNA sites were located by in situ hybridization in these two species and the cultivar R570. This supported different basic chromosome numbers and chromosome structural differences between the two species and provided a first bridge between physical and genetical mapping in sugarcane.
Mol Gen Genet 1996 Mar 07
PMID:Characterisation of the double genome structure of modern sugarcane cultivars (Saccharum spp.) by molecular cytogenetics. 860 57

Domain E, considered as the putative hormone binding domain (HBD) of the human mineralocorticoid receptor (hMR) was expressed in Escherichia coli as a fusion protein with either maltose binding protein (MBP) or glutathione S-transferase (GST). These bacterially-produced MR constructs had no steroid binding activity per se. In fact, heat shock protein association (hsp) is required for high affinity ligand-binding of the MR. After incubation of purified MBP- or GST-HBD with rabbit reticulocyte lysate, known to be rich in heat shock proteins, we obtained saturable binding of [3H]aldosterone. The Kd value for aldosterone was 0.3 nM and the Bmax = 32 pmol/mg. Hormone binding specificity was assessed by competition studies with various steroid ligands. Sucrose gradient assays performed with [3H]aldosterone-MBP-HBD revealed complex sedimenting at 8.3S and 4.9S with [3H]progesterone-MBP-HBD. Western-blot analysis of the sedimentation peak showed the concomitant presence of MBP-HBD by a monoclonal anti-MBP antibody, and hsp90 by a monoclonal anti-hsp antibody. Moreover, following incubation with the anti-rabbit hsp90 monoclonal antibody the sedimenting gradient showed a 10.4S sedimenting complex. These analyses demonstrated that the [3H]aldosterone-MBP-HBD complex is at least associated with hsp90 in reticulocyte lysate and that the HBD of hMR is sufficient to bind hsp90. Deletions of a relatively short amino- (729-766) or carboxy-terminal (940-984) region of the HBD fragment eliminated all steroid-binding properties. Overall, these results indicate that the integrity of domain E is necessary and sufficient to bind steroid ligands, agonists or antagonists, with characteristics similar to the entire native MR.
J Steroid Biochem Mol Biol 1996 Jan
PMID:Putative steroid binding domain of the human mineralocorticoid receptor, expressed in E. coli in the presence of heat shock proteins shows typical native receptor characteristics. 864 16

Fragile X syndrome is a frequent cause of mental retardation resulting from the absence of FMRP, the protein encoded by the FMR1 gene. FMRP is an RNA-binding protein of unknown function which is associated with ribosomes. To gain insight into FMRP function, we performed immunolocalization analysis of FMRP truncation and fusion constructs which revealed a nuclear localization signal (NLS) in the amino terminus of FMRP as well as a nuclear export signal (NES) encoded by exon 14. A 17 amino acid peptide containing the FMRP NES, which closely resembles the NES motifs recently described for HIV-1 Rev and PKI, is sufficient to direct nuclear export of a microinjected protein conjugate. Sucrose gradient analysis shows that FMRP ribosome association is RNA-dependent and FMRP is found in ribonucleoprotein (RNP) particles following EDTA treatment. These data are consistent with nascent FMRP entering the nucleus to assemble into mRNP particles prior to export back into the cytoplasm and suggests that fragile X syndrome may result from altered translation of transcripts which normally bind to FMRP.
Hum Mol Genet 1996 Aug
PMID:The fragile X mental retardation protein is a ribonucleoprotein containing both nuclear localization and nuclear export signals. 884 25


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