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)

Giardia lamblia, a prevalent human pathogen and one of the lineages that branched earliest from prokaryotes, can be infected with a double-stranded RNA virus, giardiavirus (GLV). The 6,277-bp viral genome has been previously cloned (A.L. Wang, H.-M. Yang, K.A. Shen, and C.C. Wang, Proc. Natl. Acad. Sci. USA 90:8595-8599, 1993; C.-H. Wu, C.C. Wang, H.M. Yang, and A.L. Wang, Gene, in press) and was converted to a transfection vector for G. lamblia in the present study. By flanking the firefly luciferase gene with the 5' and 3' untranslated regions (UTRs) of the GLV genome, transcript of the construct was synthesized in vitro with T7 polymerase and used to transfect G. lamblia WB trophozoites already infected with GLV (WBI). Optimal electroporation conditions used for the transfection were set at 1,000 V/cm and 500 microF, which resulted in expression of significant luciferase activity up to 120 h after electroporation. Furthermore, the mRNA and the antisense RNA of the luciferase gene were both detected by reverse transcription and PCR from 6 to 120 h postelectroporation, whereas no antisense RNA of luciferase was observed in the electroporated virus-free Giardia WB trophozoites. The mRNA of luciferase was detectable in the virus-free trophozoites by reverse transcription and PCR only up to 20 h after the electroporation, indicating that the introduced mRNA was replicated only by the viral RNA-dependent RNA polymerase inside the WBI cells. This expression of luciferase was dependent on the presence of UTRs on both ends of the viral genome transcript, including a putative packaging site that was apparently indispensable for luciferase expression. This is the first time that a viral vector in the form of mRNA URTs has been successfully used in transfecting a protozoan.
Mol Cell Biol 1995 Sep
PMID:Virus-mediated expression of firefly luciferase in the parasitic protozoan Giardia lamblia. 765 5

Sliding-window averaging of amino acid properties is often used for predicting protein secondary structure. Such a scheme (linear convolutional recognizer, LCR) assigns a number (weight) to each type of monomer, and then convolutes a window function with the sequence of weights to yield a decision function. Features, regions having the property of interest, are predicted to occur where the decision function exceeds some threshold. A general method for approximating the best possible window and weights is presented. The needed data are the sequences of some chains and the locations of their features. The method is applied to transmembrane helices (TMH) of membrane proteins. Optimal weights and windows are calculated, using bacteriorhodopsin and photosynthetic reaction centers as the reference chains. The predictor is then tested on other proteins. No TMH are predicted in porin, whose transmembrane segments are beta-sheets. This shows that the predictor is specific for helical segments. Few segments are predicted for non-membrane globular proteins. The predictor thus correctly rejects their hydrophobic helices. Finally, the predictor is tested with some membrane proteins whose transmembrane topology is partially known. Among their TMH, the LCR is unable to resolve 6% which are closely spaced. Taking 17 as the minimum allowed length of a predicted TMH, 4% of the known ones are missed and 6% of the predicted ones are false. For a minimum length of 10, 0.5% are missed and 14% are false. The mean magnitude of the endpoint error is about four residues. Alternative prediction methods make more errors.
J Mol Biol 1993 Jul 05
PMID:Quadratic minimization of predictors for protein secondary structure. Application to transmembrane alpha-helices. 768 96

Several double-chain ammonium amphiphiles were designed to have physicochemical properties, such as membrane fluidity and aggregate morphology, suitable for DNA transfection, according to our previous results (1, 2). Potency of the amphiphiles during the transfer of plasmid DNA into COS cells was examined. Of the amphiphiles tested, O,O'-ditetradecanolyl-N-(trimethylammonio acetyl)diethanolamine chloride (14Dea2) had the highest transfection activity. Optimal conditions for transfection of COS cells by 14Dea2 were also determined.
Biochem Mol Biol Int 1994 Nov
PMID:Design of a new cationic amphiphile with efficient DNA-transfection ability. 770 7

In addition to traditional tests, a battery of DNA probes was used to characterize 134 toxigenic and 125 nontoxigenic C.diphtheriae strains isolated in Russia in 1986-1989. 2.5% of nontoxigenic strains carried the determinants of both toxin subunits A and B, and 20% possessed at least a fragment of the gene determining toxin synthesis. Optimal conditions of hybridization technology were found. The method may be used as an alternative to traditional techniques in diagnostic studies and screenings.
Mol Gen Mikrobiol Virusol
PMID:[Use of a DNA-DNA hybridization method for studying Corynebacterium diphtheriae strains]. 773 93

Expression from both the Escherichia coli nir and nrf promoters is dependent on anaerobic induction by FNR but is further regulated by NarL and NarP in response to the presence of nitrite and nitrate in the growth medium. The nir promoter is activated by NarL in response to nitrate and nitrite and activated by NarP in response to nitrate but not nitrite. The effects of point mutations suggest that NarL and NarP both bind to the same target, which is a pair of heptamer sequences organized as an inverted repeat, centred 69 1/2 bp upstream of the transcript startpoint. The nrf promoter can be activated by either NarP or NarL in response to nitrite but is repressed by NarL in response to nitrate. Mutational analysis of the nrf promoter has been exploited to corroborate the location of the -10 hexamer and the FNR-binding site, and to find the sites essential for nitrite-dependent activation and nitrate-dependent repression. Optimal activation by NarP or NarL in response to nitrite requires an inverted pair of heptamer sequences, similar to that found at the nir promoter, but centred 74 1/2 bp upstream from the transcript start. NarL-dependent repression by nitrate is due to two heptamer sequences that flank the FNR-binding sequence. We conclude that NarL and NarP bind to the same heptamer sequences, but that the affinities for the two factors vary from site to site.
Mol Microbiol 1994 Sep
PMID:Nitrite and nitrate regulation at the promoters of two Escherichia coli operons encoding nitrite reductase: identification of common target heptamers for both NarP- and NarL-dependent regulation. 785 19

A comparative study of hGH and IL2 post-signaling effects, as examined by RNA expression (Nb29) and protein levels of the heat-shock protein hsp70, was performed in a hormone-dependent rat lymphoma cell line, Nb2-11C. Optimal doses of hGH or IL2 increased Nb29 expression in a dose-dependent manner. Addition of both mitogens to cell cultures affected Nb29 expression and mitogenesis synergystically, indicating a possible interaction between the post-receptoral mechanisms of these mitogens. Pretreatment of the cells with cholera toxin (CT) inhibited Nb29 expression, protein levels and mitogenesis of hGH- or IL2-induced cells up to 50%, indicating the involvement of Gs-proteins in the post-signaling processes of both hGH and IL2. Incubation of cell cultures with low concentrations of pertussis toxin (IAP) (0.01 ng/ml) markedly increased Nb29 expression in hGH but not in IL2-induced cells, suggesting specific involvement of the Gi-protein in post-signaling processes of hGH-induced cells. Addition of the PKC activator 12-O-tetra-decanoyl phorbol ester (TPA) to control cell cultures markedly increased the expression of Nb29 RNA levels but not mitogenesis, indicating that induction of these proteins in the cells is not sufficient for cell proliferation. Furthermore, incubation of hGH- or IL2-induced cells with the potent PKC inhibitor staurosporin (ST) decreased the levels of Nb29 in both hGH- and IL2-induced cells, although the effect of the mitogens differed significantly in their inhibition slopes. These results indicate that activation of PKC is one of the signaling pathways differentially involved in hGH and IL2 stimulation of cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Endocrinol 1994 Nov
PMID:Regulation of heat-shock protein (hsp70) gene expression by hGH and IL2 in rat Nb2 lymphoma cells. 785 20

Flavin-containing monooxygenase (FMO) activity as N,N-dimethylaniline (DMA) N-oxygenation was characterized in microsomes from the smooth dogfish shark (Squalus acathias). DMA N-oxygenase activity from the liver of the dogfish shark was linear with increasing protein content and over 60 min. The optimal temperature for catalysis was 25 degrees C with a 76 percent reduction in activity when incubated at 15 degrees C and 99 percent loss of activity at 45 degrees C. Optimal pH was approximately 9.6. The maximum velocity for DMA N-oxygenase activity was calculated to be 1.3 nmol min-1 mg-1 with an apparent Michaelis constant of 44 microM. Methimazole oxidase activity was also observed in dogfish liver microsomes which was inhibited by trimethylamine (TMA). Inhibition of DMA N-oxygenase activity by TMA and thiobenzamide was competitive, while inhibition by methimazole was not competitive. Western blot analysis indicated a single liver protein from both Squalus and Carcharhinus of approximately 50 kDa that bound to antibodies raised against FMO 2. An attempt was made to purify FMO as methimazole oxidase from the liver of the silky shark. A single peak of about 10-fold purity was observed following passage through two chromatographic media (CM-Sepharose and HA-Agarose). However, no activity was recoverable after the FMO-containing fractions were applied to a 2'5' ADP-Sepharose column.
Comp Biochem Physiol B Biochem Mol Biol 1994 Dec
PMID:Characterization of liver flavin-containing monooxygenase of the dogfish shark (Squalus acanthias) and partial purification of liver flavin-containing monooxygenase of the silky shark (Carcharhinus falciformis). 788 27

A simple and rapid purification procedure for hepatic peroxisomal multifunctional enzyme (delta 3, delta 2-enoyl-CoA isomerase/enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase) from clofibrate treated mice is described. The purification is achieved within two days using ion-exchange chromatography and an easily prepared affinity resin. The overall yield is 10% or more after a 100-fold enrichment from the cytosolic fraction of liver tissue. The native enzyme is a monomer with a molecular mass of 75 kDa. The protein is blocked in the N-terminus but internal amino acid sequences was obtained after proteolytic cleavage. Western blot analysis indicated proteolysis of multifunctional enzyme in different subcellular fractions derived from liver tissue. The hydratase activity of the enzyme is heat-labile and highly dependent on the concentration of Tris buffer or potassium chloride present. Optimal activity was found around 37 degrees C and pH 7. The enzyme also shows dehydrogenase and isomerase activity.
Comp Biochem Physiol Biochem Mol Biol 1994 Aug
PMID:Purification and characterization of multifunctional enzyme from mouse liver peroxisomes. 795 67

Optimal T-cell activation requires both an antigen-specific signal delivered through the T-cell receptor and a costimulatory signal which can be delivered through the CD28 molecule. CD28 costimulation induces the expression of multiple lymphokines, including interleukin 2 (IL-2). Because the c-Rel transcription factor bound to and activated the CD28 response element within the IL-2 promoter, we focused our study on the mechanism of CD28-mediated regulation of c-Rel in human peripheral blood T cells. We showed that CD28 costimulation accelerated the kinetics of nuclear translocation of c-Rel (and its phosphorylated form), p50 (NFKB1), and p65 (RelA). The enhanced nuclear translocation of c-Rel correlated with the stimulation of Il-2 production and T-cell proliferation by several distinct anti-CD28 monoclonal antibodies. This is explained at least in part by the long-term downregulation of I kappa B alpha following CD28 signalling as opposed to phorbol myristate acetate alone. Furthermore, we showed that the c-Rel-containing CD28-responsive complex is enhanced by, but not specific to, CD28 costimulation. Our results indicate that c-Rel is one of the transcription factors targeted by CD28 signalling.
Mol Cell Biol 1994 Dec
PMID:Effect of CD28 signal transduction on c-Rel in human peripheral blood T cells. 796 33

The interaction of antibodies from blood sera of patients with autoimmune pathology, systemic lupus erythematosus with oligoribonucleotides was studied. The RNA-hydrolyzing activity was shown to be an intrinsic property of autoantibodies. Enzymic activity of antibodies in hydrolysis of poly(U) was estimated at 20-40% of that of RNase A. In contrast to known eukaryotic RNases, the autoantibodies possess a specific RNA-hydrolyzing activity for oligo r(A). The RNA-nicking activity of antibodies in hydrolysis of oligoadenylates was more higher than with hydrolysis of oligo d(A). Optimal conditions of r(pA)13 hydrolysis were selected, including the optimal of pH = 8.7.
Mol Biol (Mosk)
PMID:[Interaction of catalytically active antibodies with oligoribonucleotides]. 799 Aug 1


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