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)

We have studied the molecular mechanism of the negative regulation by flgM of the late operons of the flagellar regulon of Salmonella typhimurium. A 7.8 kDa protein that was identified as the flgM gene product was purified to homogeneity; its amino-terminal sequence was identical to the deduced sequence except for the lack of the initiating methionine. The purified FlgM repressed transcription from the fliC promoter, one that is activated by the sigma factor, FliA (sigma F). No DNA-binding activity was detected in FlgM. Chemical cross-linking experiments showed that the purified FlgM bound to sigma F and disturbed its ability to form a complex with RNA polymerase core enzyme. These results indicate that FlgM is a novel type of negative regulator that probably inactivates the flagellum-specific sigma factor through direct interaction, i.e. it is an anti-sigma factor.
Mol Microbiol 1992 Nov
PMID:A novel transcriptional regulation mechanism in the flagellar regulon of Salmonella typhimurium: an antisigma factor inhibits the activity of the flagellum-specific sigma factor, sigma F. 145 55

The phytochrome gene (phyCer) of the moss Ceratodon purpureus was isolated and characterized. phyCer is composed of three coding exons: exon I of 2035 bp, exon II of 300 bp and exon III of 1574 bp. The deduced polypeptide encoded by exon I and II exhibits substantial sequence homology to the conserved NH2-terminal chromophore domain of known phytochromes. In contrast, the COOH-terminal polypeptide encoded by exon III shows no sequence homology to any phytochrome molecule. phyCer most likely represents a single-copy gene and is expressed in a light-independent manner. From the DNA sequence analysis it can be deduced that the PhyCer polypeptide is composed of 1303 amino acids (including the starting Met) which predicts a molecular mass for PhyCer of 145 kDa. The polypeptide encoded in exon III exhibits striking homology within the 300 carboxy-terminal amino acids to the catalytic domain of protein kinases. The carboxy terminus of PhyCer was found to be most homologous to protein-tyrosine kinases of Dictyostelium discoideum and to the products of retroviral oncogenes which belong to the Raf-Mos serine/threonine kinase family. From the hydropathy profile PhyCer appears to be a soluble protein. The predicted structure suggests that PhyCer represents a soluble light-sensor protein kinase which is linked with a cellular phosphorylating cascade.
Plant Mol Biol 1992 Dec
PMID:Molecular cloning of a novel phytochrome gene of the moss Ceratodon purpureus which encodes a putative light-regulated protein kinase. 146 36

The enzyme peptide methionine sulfoxide reductase catalyzes the conversion of methionine sulfoxide residues in proteins to methionine. The 636 nucleotide coding region of the peptide methionine sulfoxide reductase gene has been amplified from a genomic clone using the polymerase chain reaction and the product was subcloned into plasmid pGEX-2T downstream of the glutathione S-transferase gene under control of the tac promoter. Escherichia coli XL1-Blue cells transformed with this plasmid and induced with isopropylthio-beta-galactoside expressed high levels of the fusion protein. The protein was soluble and was purified to homogeneity by affinity binding to a glutathione-agarose resin followed by cleavage of the fusion protein with thrombin. Both the fusion protein and the purified peptide methionine sulfoxide reductase protein showed high peptide methionine sulfoxide reductase activity.
Cell Mol Biol 1992 Aug
PMID:High level expression and purification of peptide methionine sulfoxide reductase in Escherichia coli. 146 11

An acidic glycoconjugate could be extracted from a delipidated residue fraction of [3H]galactose, [3H]mannose or [32P]orthophosphate metabolically labeled Entamoeba histolytica with water/ethanol/diethylether/pyridine/NH4OH (15:15:5:1:0.017). The radioactively labeled glycoconjugate comprised 50-55% of the total [3H]galactose label incorporated into macromolecules. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the radiolabeled glycoconjugate showed two diffuse smears centering around 110 kDa and 45 kDa. Similar profiles were observed for both [3H]galactose- and [32P]orthophosphate-labeled glycoconjugate. No such bands were visible in [35S]methionine-labeled material. The hydrophobic nature of this glycoconjugate was inferred from its chromatographic behavior on phenyl-Sepharose. The molecule was rendered hydrophilic after digestion with phosphatidylinositol-specific phospholipase C. It was also sensitive to deamination by nitrous acid. Mild acid hydrolysis led to its fragmentation into smaller molecules as revealed by Sepharose 4B chromatography. Paper chromatographic analysis of the depolymerized [3H]galactose- and [3H]mannose-labeled fragments revealed that each was sensitive to alkaline phosphatase. The major dephosphorylated fragment migrated as an apparent galactose and mannose containing disaccharide which migrated identically to the Gal beta 1-4Man disaccharide derived from the lipophosphoglycan of Leishmania donovani. The above data support the existence of a major acidic glycoconjugate in E. histolytica bearing striking structural similarities to the lipophosphoglycan of Leishmania.
Mol Biochem Parasitol 1992 Nov
PMID:Identification and partial characterization of a lipophosphoglycan from a pathogenic strain of Entamoeba histolytica. 147 94

Our previous studies indicated that regulation of bovine parathyroid chromogranin-A (CgA) by 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] may occur at the level of CgA turnover or mRNA translation. In the present study, immunoprecipitation of extracts of bovine parathyroid cells that had been pulse chased with [35S]methionine revealed that 1,25-(OH)2D3 had no effect on the disappearance time of intracellular CgA. Therefore, we examined the effect of 1,25-(OH)2D3 on the polyribosome profile of CgA mRNA analyzed by sucrose density gradients. In the presence of 1,25-(OH)2D3, there was a dose-dependent recruitment of CgA mRNA into the denser polyribosomal fractions by 24 h. To determine whether this increased ribosome loading represents increased or decreased efficiency of mRNA translation, ribosome transit time experiments were conducted. The average ribosome transit time and the specific PTH ribosome transit time were not altered by 1,25-(OH)2D3. However, that for CgA was doubled in the presence of 1,25-(OH)2D3. Thus, parathyroid CgA synthesis is regulated by the vitamin D sterol at the level of peptide chain elongation. These studies, therefore, explain the lack of quantitative correspondence between 1,25-(OH)2D3-induced CgA gene transcription and CgA protein levels by revealing a previously unsuspected level of regulation of mRNA translation in the parathyroid cell.
Mol Endocrinol 1992 Nov
PMID:1,25-Dihydroxycholecalciferol regulates chromogranin-A translatability in bovine parathyroid cells. 148 Jan 70

A sialic acid binding lectin, AchatininH was purified from the hemolymph of Achatina fulica snail. To identify the site of synthesis of AchatininH, in vitro incubation studies in presence of labelled amino acid precursor were performed. Different organs from the snail were sliced and incubated in methionine-deficient Eagle's minimum essential medium containing [35S]-methionine at 25 degrees C for 5 h. After termination of incubation, tissues were homogenized, centrifuged and the de novo synthesized protein was immunoprecipitated with specific AchatininH antibody, followed by protein-A. The precipitated antigen-antibody complex was analysed by SDS-PAGE. Data obtained from native gel electrophoresis and SDS-PAGE radioautographic analysis indicates that AchatininH is synthesized in the albumen gland.
Mol Cell Biochem 1992 Nov 18
PMID:Albumen gland of the snail Achatina fulica is the site for synthesis of AchatininH, a sialic acid binding lectin. 148 46

Spatial structures of proteolytic segment A (sA) of bacterioopsin of Halobacterium halobium (residues 1-36) solubilized in the mixture of methanol-chloroform (1:1), 0.1 M LiClO4 or in perdeuteriated sodium dodecyl sulfate (SDS) micelles, were determined by 2D 1H-NMR techniques. Most of the resonances in 1H-NMR spectra of fragment A were assigned using DQF-COSY, TOCSY and NOESY spectra. Deuterium exchange rates for amide protons were measured in series of NOESY spectra. 324 and 400 NOESY cross-peak volumes were measured in NOESY spectra of sA in mixture of organic solvents and SDS micelles, respectively. The sA structure was determined by local structure analysis, distance geometry calculation with program DIANA and systematic search for energetically allowed side chain rotamers consistent with NOESY cross-peak volumes. The structures of sA are similar in both milieus. These structures have the right-handed alpha-helical region from Pro-8 to Met-32 with root mean square deviation (RMSD) of 0.25 A between back bone heavy atoms and fit well with Pro-8 to Met-32 alpha-helical region in electron cryo-microscopy (ECM) model of bacteriorhodopsin [4]. The C-terminal region Gly-33-Asp-36 is disordered in both milieus, while N-terminal region Ala-2-Gly-6 in organic solvents has a fixed structure (RMSD of 0.25 A) stabilized by the Thr-5 NH...O=C Gln-3 and Ile-4 NH...O = C Ala-2 hydrogen bonds. This region of sA in SDS micelles has disordered structure with RMSD of 1.44 A for back bone heavy atoms. Torsion angles chi 1 of sA were unequivocally determined for 72% of side chains in the alpha-helical region and are identical in both milieus.
Mol Biol (Mosk)
PMID:[Spatial structure of (1-36)bacterioopsin solubilized in a methanol-chloroform mixture with sodium dodecylsulfate micelles]. 149 81

The earliest time of onset of embryonic genome activation in golden hamsters was investigated. The inhibition of transcription by alpha-amanitin (11 micrograms/ml) in cultured embryos resulted in a total arrest of development of early 2-cell embryos (26 hr post-egg activation); under similar conditions, immediate cleavage divisions of 1-, late 2-, 4-, and 8-cell embryos were not affected. Electrophoretic analysis of [35S]methionine-labeled embryonic proteins showed that alpha-amanitin treatment apparently inhibited transcription-dependent protein synthesis in early 2-cell and, to some extent, in late 2-cell when compared to 4-cell embryos. Analysis of total RNA synthesis, using [alpha 32P]-UTP or [32P]-orthophosphate, showed that there was a high proportion of radioactivity associated with the macromolecular fraction (RNA) at the early and late 2-cell stages and at the 4-cell stage compared to that at the 1-cell stage. These results indicate that the de novo synthesis of RNA, encoded by the embryonic genome, occurs at the 2-cell stage and that the second and subsequent cleavage divisions of hamster preimplantation embryos are dependent on new transcriptional activity. This initial activity of the embryonic genome in hamsters is coincident with several characteristic features of in vitro development such as a block to development, synthesis of major proteins, change in energy substrate preference, phosphate-inhibition of development and a requirement for amino acids.
Mol Reprod Dev 1992 Jul
PMID:Golden hamster embryonic genome activation occurs at the two-cell stage: correlation with major developmental changes. 149 72

Regulation of airway repair after injury is poorly understood but is thought to be important in the development of airway diseases such as chronic bronchitis and asthma. There is evidence that fibronectin (Fn), an extracellular matrix glycoprotein, has a role in repair processes. In addition, transforming growth factor-beta (TGF-beta) is also likely involved in would healing and is known to influence extracellular matrix constituents in other cell systems. We postulated that TGF-beta may effect airway repair by modulating Fn production from airway epithelial cells. To examine this hypothesis, we studied the effect of TGF-beta 1 on Fn production by bovine bronchial epithelial cells in culture. Fn, released into the media of cultures exposed to TGF-beta 1, increased in a dose- and time-responsive fashion. Fn in the cell layer also increased in response to TGF-beta 1. De novo protein synthesis was demonstrated by an increase in [35S]methionine incorporation into Fn immunoprecipitated from media of TGF-beta-treated cultures. TGF-beta 1 also induced an increase in expression of Fn mRNA from cultured bronchial epithelial cells, suggesting that TGF-beta modulates Fn production of these cells, at least in part, through modulation of Fn gene expression. These data support a role for TGF-beta in airway repair through modulation of Fn production by airway epithelium.
Am J Respir Cell Mol Biol 1992 Aug
PMID:Modulation of fibronectin production of bovine bronchial epithelial cells by transforming growth factor-beta. 149 3

We have investigated whether human lymphoid cells are able to synthesize and secrete human PRL (hPRL) and to express PRL receptors. Metabolic labeling with [35S]methionine and immunoprecipitation of cell extracts from human mononuclear cells (MNC) and a human T lymphocyte cell line with an antiserum against hPRL revealed protein of M(r) 23,000, identical in size to pituitary hPRL. Dilution curves of lymphocyte immunoreactive hPRL were parallel to those obtained with pituitary hPRL in an immunoradiometric assay using two monoclonal antibodies against hPRL. Polymerase chain reaction experiments with primers located in the coding sequence of hPRL showed that the hPRL gene was expressed in MNC. Furthermore, cDNA cloning and sequence analysis indicated the presence of an extra 5' noncoding exon previously described for decidual hPRL. When MNCs were further separated into B cells, T cells, and monocytes, the expression of hPRL appeared to be mainly associated with the T lymphocyte fraction. The hPRL transcript was also detected in thymocytes and in a set of human lymphoid cell lines. Finally, polymerase chain reaction experiments revealed a ubiquitous distribution of PRL receptor gene expression in B cells, T cells, and monocytes. The presence of the receptor for PRL and production of PRL by T lymphocytes suggest a possible autocrine or paracrine effect of PRL in immune cell function.
Mol Endocrinol 1992 Jul
PMID:Expression of prolactin and its receptor in human lymphoid cells. 150 18


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