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

Plasma membranes have been prepared from porcine thyroid glands using sucrose gradients. The fractions having a density in sucrose of 1.18 g/ml mainly contained plasma membranes and were moderately contaminated with other subcellular components as shown by marker enzyme data. Purified plasma membranes incubated in the presence of [32-P]gamma ATP incorporated 32-P. Kinetics of incorporation of 32-P into endogenous substrates studied in various buffers and with increasing ATP concentration suggest a phosphodephosphorylating system related to cAMP-dependent protein kinase and phosphoprotein phosphatase activities. The two enzymatic activities associated with plasma membranes have been demonstrated using exogenous substrates. cAMP increases and fluoride ions decrease the extent of membrane phosphorylation. The specific activity of protein kinase was 10-12 times higher than in the initial homogenate and was only slightly enhanced in the presence of 0.5% Nonidet as compared to microsomal fraction. cAMP binding to membrane proteins was 3 times higher than to the other particulate fractions. TSH present in the incubating medium or added after 5 min of 32-P labelling induced a rapid stimulation of endogenous phosphorylation followed by a rapid decrease. Phosphorylated membrane substrates were analyzed: high voltage paper electrophoresis after partial hydrolysis indicated that [32-P]phosphate is incorporated into serine and threonine residues as o-phosphate derivatives. SDS-polyacrylamide gel electrophoresis showed several 32--labelled fractions. When enhanced by cAMP, no specific phosphorylation of protein components was observed.
Mol Cell Endocrinol 1975 May
PMID:Phosphorylation of purified thyroid plasma membranes incubated with [32-P]ATP. 16 13

Serratia marcescens Sa-3 possesses two homoserine dehydrogenases and neither has any aspartokinase activity unlike the case of Escherichia coli enzymes. The two enzymes have been separated. One of them is active with either NAD+ or NADP+ and has been purified about 180-fold to homogeneity. This enzyme is completely repressed by the presence of 1 mM methionine or homoserine in the growth medium, but its activity is unaffected by any amino acid of the aspartate family either singly or together. In many of its properties (such as pH optimum, Km for substrate and cofactors), it resembles its counterpart in E. coli K12. Potassium ions stabilize the enzyme but are not essential for activity. Its molecular weight is around 155,000 as determined by gel filtration and approximately 76,000 by SDS-polyacrylamide gel electrophoresis. This suggests that the enzyme has two subunits (polypeptide chains) in the molecule: 8 M urea has no effect on enzyme activity. This enzyme represents approximately 30% of the total homoserine dehydrogenase activity of S. marcescens unlike in Salmonella typhimurium and E. coli K12 where it is a minor or a negligible component.
Mol Cell Biochem 1976 Jul 30
PMID:Methionine-repressible homoserine dehydrogenase of Serratia marcescens: purification and properties. 18 74

Using purified yeast mitochondrial DNA as a template for E. coli RNA polymerase (holoenzyme) complementary mitochondrial RNA has been synthesized in vitro. This RNA has been used to direct a low background E. coli S-30 protein-synthesizing system. The synthesis of mitochondrial polypeptides has been detected by using antiserum raised against purified cytochrome c oxidase holoenzyme and shown to be specific for this antigen. The antiserum-antigen complex was dissociated and subject to SDS-polyacrylamide gel electrophoresis and the presence of 3 polypeptides of 39, 31, and 26 X 10(3) daltons molecular weight demonstrated, which correspond to the subunits synthesized by mitochondria in whole cells which are inhibited with cycloheximide.
Mol Gen Genet 1977 Jan 07
PMID:Synthesis of cytochrome c oxidase polypeptides in an Escherichia coli cell-free system directed by Saccharomyces cerevisiae mitochondrial DNA. 18 80

Particles carrying heterogeneous nuclear RNA (30 S-particles) were prepared from rat liver and Zajdela hepatoma ascites cell nuclei after ultrasonic disruption. The ribonucleoprotein structures were disintegrated in the presence of 100mM spermidine. Using chromatography on Sepharose-polyadenylate a protein component has been obtained which possessed high affinity for heterogeneous nuclear RNA, polyuridylate and polyadenylate, and double-stranded DNA. This protein was the main species of the ribonucleoprotein studied; it showed bands with molcular weights of 37000 and 40000 respectively in SDS gel electrophoresis. The RNA-binding proteins isolated from liver and hepatoma had identical molecular weights and the same affinity for Sepharose-polyadenylate used in the isolation.
Mol Biol Rep 1977 Sep
PMID:Preparation in undenatured form of the main protein bound to heterogeneous nuclear RNA in liver and hepatoma cells. 19 32

We have previously shown that cultured bovine pituitary or hypothalamic cells incorporate 3H-labeled amino acids into high molecular weight glycoproteins containing the antigenic determinants of both corticotropin (ACTH) and beta-endorphin. We now report resolution of this 3H-labeled ACTH/beta-endorphin-like material into two predominant size classes upon SDS polyacrylamide-gel electrophoresis with apparent molecular weights (Mr) of 41 500 +/- 1600 and 36 000 +/- 1100. Isoelectric focusing revealed these components to be basic proteins with apparent isoelectric points greater than 8.5. Overnight trypsinization generated a 3H-labeled fragment comigrating with synthetic beta-lipotropin (61-69) [beta-endorphin (1-9)] upon paper electrophoresis which was immunoprecipitable with antibody directed against the corresponding synthetic fragment. Limited trypsinization of bovine immunoreactive ACTH/beta-endorphin extracted from freshly obtained bovine hypothalamic and anterior pituitary tissue, generated fragments which possessed ACTH bioreactivity. Both bovine pituitary and hypothalamic derived material are similar with respect to these foregoing physiochemical parameters and appear to be larger than the reported forms in mouse pituitary.
Mol Cell Endocrinol 1979 Dec
PMID:Preliminary characterization of in vitro synthesized hypothalamic precursor ACTH/beta-endorphin-like material. 23 Jan 5

A relationship between serine-induced growth sensitivity and the cAMP-CAP complex is established. Mutants of Escherichia coli K 12 deficient either in the cya or crp gene function exhibit a resistant phenotype on serine media although they harbor a relA allele normally leading to sensitivity toward serine. The presence of a crp allele in a cya delta relA background restores the sensitivity phenotype, while the analysis of serine resistant mutants selected from a crp cya delta relA strain shows that the mutation leading to resistance is located at, or very near, the crp gene, giving a more or less Crp- phenotype. In addition crp cya delta relA strains excrete large quantities of 2-ketobutyrate when grown on glucose M63 medium. This excretion is unambiguously linked to the presence of the crp allele and is correlated with an enhanced threonine deaminase activity. Besides, the complex regulation exerted on the acetolactate synthase activities is discussed.
Mol Gen Genet 1979 Nov
PMID:Involvement of cyclic AMP and its receptor protein in the sensitivity of Escherichia coli K 12 toward serine: excretion of 2-ketobutyrate, a precursor of isoleucine. 23 Apr 7

Yeast cells (Saccharomyces cerevisiae) were grown in the presence of [14C]phenylalanine and pulse-labelled with [3H]phenylalanine in the presence of cycloheximide. The proteins extractable into chroloform: methanol (2:1) were isolated from mitochondria and analysed by SDS gel filtration. Four protein fractions varying in molecular weight were separated. In order to identify the transcriptional origin and the site of protein synthesis ethidium bromide was used. Different sensitivity of protein syntheses to various concentrations of ethidium was shown. These data are discussed in relation to the possible presence of two classes of membrane-bound polyribosomes in mitochondria.
Mol Cell Biochem 1977 Feb 04
PMID:Intramitochondrial synthesis of membrane proteins in yeast: differential inhibition by ethidium. 32 93

A lambda phage has been isolated which specifically transduces the Escherichia coli pheS and pheT genes coding for the alpha and beta subunits of the phenylalanyl-tRNA synthetase (PRS). This phage transduces with high frequency (i) several temperature-sensitive PRS mutants to thermoresistance and (ii) a p-fluorophenylalanine resistant PRS mutant to sensitivity against this amino-acid analog. The in vitro PRS activities of such lysogens suggest that the alpha and beta subunits coded by the transducing phage complement the mutant host PRS-subunits in vivo by means of formation of hybrid enzymes. The transducing lambda phages were also used to infect UV light irradiated cells. The SDS-gel electrophoretic analysis of the proteins synthesized in such cells revealed that the phage codes at least for four different E. coli proteins. Two proteins with molecular weights of 94,000 and 38,000 daltons cross-reacted with an anti PRS serum and were thus identified as the beta and alpha subunits of PRS, respectively. A third protein with a molecular weight of 22,000 daltons is identical with the ribosomal initiation factor IF3 (Springer et al., 1977b). The other protein (Mr 78,000) is still unidentified.
Mol Gen Genet 1977 Apr 29
PMID:A specialized transducing lambda phage carrying the Escherichia coli genes for phenylalanyl-tRNA synthetase. 32 76

Analysis of lambda phage infection of the host mutant ER437 by SDS polyacrylamide gel electrophoresis and autoradiography has revealed altered expression of repressor and integration function (Int). We show that in this host Int as well as repressor synthesis is not dependent upon the lambdacIII gene product in the usual manner, nor is their synthesis turned off in the normal way.
Mol Gen Genet 1977 Oct 24
PMID:Repressor and int synthesis of bacteriophage lambda in the E. coli host mutant ER437. 34 Aug 86

The cytoplasmic 80s ribosomal proteins from the cells of yeast Sachharomyces cerevisiae were analysed by SDS two-dimensional polyacrylamide gel electrophoresis. Seventyfour proteins were identified and consecutively numbered from 1 to 74. Upon oxidation of the 80s proteins with performic acid, ten proteins (no. 15, 20, 35, 40, 44, 46, 49, 51, 54 and 55) were dislocated on the gel without change of the total number of protein spots. Five proteins (no. 8, 14, 16, 36 and 74) were phosphorylated in vivo as seen in 32P-labelling experiments. The large and small subunits separated in low magnesium medium were analyzed by the above gel electrophoresis. At least forty-five and twenty-eight proteins were assumed to be in the large and small subunits, respectively. All proteins found in the 80s ribosomes, except for no. 3, were detected in either subunit without appearance of new spots. The acidic protein no. 3 seems to be lost during subunit dissociation.
Mol Gen Genet 1978 Jul 04
PMID:Yeast ribosomal proteins. I. Characterization of cytoplasmic ribosomal proteins by two-dimensional gel electrophoresis. 35 32


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>