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)

Structural studies were performed in two atypical polysaccharides, PS-1 and PS-2 isolated from the broth of a Tn5 mutant strain of Xanthomonas campestris. Sugar composition, methylation and nuclear magnetic resonance analyses were determined. PS-1 is composed by repeating trisaccharide units containing D-glucose, D-mannose and having the structure. carbohydrate sequence [see text]. Preliminary studies on the PS-2 show a polymer composed in a large extent of rhamnose. Unexpectedly, this polysaccharide is soluble in alcoholic solutions.
Cell Mol Biol (Noisy-le-grand) 1998 May
PMID:Structure of an extracellular mannosylated cellulose produced by a mutant strain of Xanthomonas campestris. 962 Apr 40

The treatment of Leuconostoc mesenteroides NRRL B-512F dextransucrase with lysine specific reagent, pyridoxal 5'-phosphate (PLP) at pH 5.2 and 30 degrees C resulted in the loss of enzyme activity. The inactivation by PLP could be reversed completely by dilution or dialysis. Sucrose as well as acceptor substrates, glucose and dextran protected the enzyme against inactivation by PLP. A statistical, kinetic analysis of the inactivation by PLP showed that one lysine residue is essential for the enzyme activity. All these results showed that one lysine residue present at the active is essential for the activity of dextransucrase.
Biochem Mol Biol Int 1998 May
PMID:Chemical modification of dextransucrase from Leuconostoc mesenteroides NRRL B-512F by pyridoxal 5'-phosphate: evidence for the presence of an essential lysine residue at the active site. 962 71

Sucrose gradient centrifugation combined with electron microscopy revealed that undifferentiated SH-SY5Y cells contain predominantly one population of noradrenaline containing vesicles, i.e. large dense cored vesicles. These vesicles have been purified approximately twenty times using sucrose/D2O gradients. Electron microscopy of sucrose/D2O fractions confirms that large dense cored vesicles are enriched in the fractions containing predominantly dopamine- -hydroxylase, chromogranin A, noradrenaline and neuropeptide Y. The membranes of these vesicles contain the typical large dense cored vesicle markers dopamine- -hydroxylase, synaptotagmin, cytochrome b561 and rab 3. Stimulation of SH-SY5Y cells with carbachol and KCl shows that noradrenaline and neuropeptide Y are released in the same proportion as stored in the large dense cored vesicles. The immuno-blot pattern and intensity of chromogranin A and chromogranin B present in large dense cored vesicles and in the released material were definitely the same. This suggests that noradrenaline and the proteins/peptides are released in the same molar stoichiometry as they are stored in large dense cored vesicles. These data provide for the first time experimental evidence that the neuroblastoma cell line SH-SY5Y contains functionally active large dense cored vesicles similar to those of sympathetic neurons and indicate that this cell line is a suitable experimental cell model to study the exocytotic pathway of large dense cored vesicles.
Int J Mol Med 1998 Jan
PMID:The storage of noradrenaline, neuropeptide Y and chromogranins in and stoichiometric release from large dense cored vesicles of the undifferentiated human neuroblastoma cell line SH-SY5Y. 985 6

Sucrose density gradient purified plasma membranes isolated from brown adipose tissue of cold-acclimated hamsters (4-10 weeks at 0-4 degreesC) were analysed for the content of the short (GsalphaS) and long (GsalphaL) variants of Gsalpha protein (the alpha subunit of the stimulatory G protein) and compared with the membranes isolated from control animals. The relative ratio between the two variants (GsalphaS/GsalphaL) decreased from 0.48 to 0.24 (P<0.01). This result, obtained by electrophoretic resolution of membrane proteins by standard SDS-PAGE and an immunoblot analysis with an antiserum oriented against an internal sequence of Gsalpha, was verified by resolution on urea-containing gels and an antiserum oriented against the C-terminus decapeptide of Gsalpha. Under these conditions, the GsalphaS/GsalphaL ratio was decreased from 0.41 to 0.31 (P<0.05). The total amount of both isoforms (GsalphaS plus GsalphaL) decreased to 83% (P<0.05) or 68% (P<0.01) by standard or urea SDS-PAGE respectively. These data demonstrate that cold-acclimation of hamster brown adipose tissue is associated with preferential decrease in the plasma membrane density of the short variant of the Gsalpha protein.%This decrease was paralleled by an increase in the other plasma membrane constituents, [3H]CGP12177 binding sites, [3H]ouabain binding sites and Na,K-ATPase activity to 147%, 212% and 191% respectively.
J Mol Endocrinol 1999 Feb
PMID:The decrease in the short variant of gsalpha protein is associated with an increase in [3H]CGP12177 binding, [3H]ouabain binding and Na, K-ATPase activity in brown adipose tissue plasma membranes of cold-acclimated hamsters. 992 80

Through reverse transcription-polymerase chain reaction using degenerate oligonucleotide primers, a VCP homolog was identified in African trypanosomes. Sequence analysis shows a 72 and 64% deduced amino acid identity, respectively, with mouse VCP and yeast Cdc48p. Southern analysis indicates tbVCP to have a single locus with two alleles. Antibodies generated against recombinant protein recognize a 95 kDa protein in whole cell lysates of both procyclic and bloodstream trypanosomes. There is an approximately four-fold greater expression of TbVCP protein in the procyclic stage of the trypanosome life cycle. Subcellular fractionation and immunofluorescence with anti-TbVCP antibodies indicate the majority of TbVCP to be cytoplasmically localized with a small subset associated with membranes. Sucrose velocity sedimentation and gel filtration size analysis studies suggest that TbVCP is a homohexameric particle as has been demonstrated with other VCP homologs. Also like other VCP homologs, TbVCP contains an NEM-inhibitable ATPase activity. This is the first characterization of an AAA (ATPases Associated with a variety of cellular Activities) family member in African trypanosomes.
Mol Biochem Parasitol 1999 Jan 05
PMID:Molecular cloning and biochemical characterization of a VCP homolog in African trypanosomes. 1002 5

Sucrose synthase, which cleaves sucrose in the presence of uridine diphosphate (UDP) into UDP-glucose and fructose, is thought to be a key determinant of sink strength of heterotrophic plant organs. To determine the roles of the enzyme in carrot, we characterized carrot sucrose synthase at the molecular level. Two genes (Susy*Dc1 and Susy*Dc2) were isolated. The deduced amino acid sequences are 87% identical. However, the sequences upstream of the translation initiation codons are markedly different, as are the expression patterns of the two genes. Susy*Dc2 was exclusively expressed in flowers. Transcripts for Susy*Dc1 were found in stems, in roots at different developmental stages, and in flower buds, flowers and maturing seeds, with the highest levels in strong utilization sinks for sucrose such as growing stems and tap root tips. Expression of Susy*Dc1 was regulated by anaerobiosis but not by sugars or acetate. The carrot sucrose synthase protein is partly membrane-associated and this insoluble form may be directly involved in cellulose biosynthesis. Tap roots of the carrot cultivar used accumulated starch in the vicinity of the vascular bundles, which correlated with high sucrose synthase transcript levels. This finding suggests that soluble sucrose synthase in tap roots channels sucrose towards starch biosynthesis. Starch accumulation appears to be transient and may be involved in sucrose partitioning to developing tap roots.
Plant Mol Biol 1999 Jan
PMID:Tissue-specific expression of two genes for sucrose synthase in carrot (Daucus carota L.). 1008 Jul

Sucrose gradients have been widely used to study the translational activity of mRNA species in meiotic and haploid spermatogenic cells in mammals. Unfortunately, the results of these studies have been very inconsistent. The purpose of the present study was to obtain accurate and reproducible measurements of the translational activity of a large number of testicular mRNA in sucrose gradients. Extracts of adult testes and cultured seminiferous tubules were sedimented on sucrose gradients, and the distribution of 18 mRNA species was quantified by phosphoimaging. The proportions of various mRNA species sedimenting with polysomes in meiotic and haploid cells (approximately 6-74%) is less than typical of efficiently translated mRNAs (85-90%), demonstrating that the initiation of translation of virtually all mRNA species is at least partially inhibited and that the extent of inhibition is mRNA-specific. Most mRNA species in meiotic and early haploid spermatogenic cells are translated on polysomes in which the ribosome spacing is somewhat wider than in somatic cells, 100-150 verses 80-100 bases. However, the ribosome spacing on protamine mRNAs is unusually close (40-50 bases), and the spacing on poly(A) binding protein mRNA is unusually wide (212-272 bases), thus suggesting that the rate of translational initiation, termination and/or elongation is regulated on translationally active forms of certain mRNA.
Mol Hum Reprod 1999 Mar
PMID:A quantitative sucrose gradient analysis of the translational activity of 18 mRNA species in testes from adult mice. 1033 53

Somatic chromosomes of a wild relative of sugarcane (Saccharum spontaneum L.) anther culture-derived clone (AP 85-361, 2n = 32) were identified and characterized by computer-aided imaging technology and molecular cytological methods. The presence of four satellite chromosomes and four nearly identical chromosome sets suggests that the clone is a tetrahaploid with the basic number x = 8. A quantitative chromosome map, or idiogram, was developed using image analysis of the condensation pattern (CP) at the prometaphase stage of somatic chromosomes. The 45S and 5S ribosomal RNA gene (rDNA) loci were simultaneously visualized by multi-color fluorescence in situ hybridization (McFISH) and precisely localized to the regions of 3p3.1 and 6q1.3 on the idiogram. The simultaneous visualization of two sets of four ribosomal RNA genes confirms tetraploidy of this clone. This conclusion is consistent with results of molecular marker mapping. The quantitative chromosome map produced will become the foundation for genome analyses based on chromosome identity and structure. Previously impossible identification of small chromosomes and untestable hypotheses about the polyploid nature of plants can now be settled with these two approaches of quantitative karyotyping and FISH.
Plant Mol Biol 1999 Apr
PMID:Quantitative chromosome map of the polyploid Saccharum spontaneum by multicolor fluorescence in situ hybridization and imaging methods. 1038 Aug 3

Sucrose is the photoassimilate transported from the leaves to the fruit of tomato yet the fruit accumulates predominantly glucose and fructose. Hydrolysis of sucrose entering the fruit can be accomplished by invertase or sucrose synthase. Early in tomato fruit development there is a transient increase in sucrose synthase activity and starch which is correlated with fruit growth and sink strength suggesting a regulatory role for sucrose synthase in sugar import. Using an antisense sucrose synthase cDNA under the control of a fruit-specific promoter we show that sucrose synthase activity can be reduced by up to 99% in young fruit without affecting starch or sugar accumulation. This result calls into question the importance of sucrose synthase in regulating sink strength in tomato fruit.
Plant Mol Biol 1999 May
PMID:Transgenic tomato plants with decreased sucrose synthase are unaltered in starch and sugar accumulation in the fruit. 1041 1

Sucrose is one of several low-molecular-weight compounds that cyanobacteria accumulate in response to osmotic stress and which are believed to act as osmoprotectants. The genome of the cyanobacterium Synechocystis sp. PCC 6803 contains a 2163 bp open reading frame (ORF) that shows similarity to genes from higher plants encoding sucrose-phosphate synthase (SPS), the enzyme responsible for sucrose synthesis. The deduced amino acid sequence shows 35-39% identity with known higher-plant SPS sequences. The putative Synechocystis sps gene was cloned from genomic DNA by PCR amplification and expressed as a His6-tagged amino-terminal fusion protein in Escherichia coli. The expressed protein was purified and shown to be a functional SPS enzyme, confirming the identity of the ORF, which is the first sps gene to be cloned from a prokaryotic organism. The Synechocystis SPS has a molecular mass of 81.5 kDa, which is smaller than the typical higher-plant SPS subunit (117-119 kDa), and lacks the phosphorylation site motifs associated with light- and osmotic stress-induced regulation of SPS in higher plants. The enzyme has Km values for UDPG1c and Fru6P of 2.9 mM and 0.22 mM, respectively, with a Vmax of 17 micromol per minute per mg protein and a pH optimum of 8.5. Unlike the higher-plant enzyme, ADPG1c, CDPG1c and GDPG1c can substitute for UDPG1c as the glucosyl donor with Km values of 2.5, 7.2 and 1.8 mM, respectively. The enzyme is activated by Mg2+ but not by G1c6P, and is only weakly inhibited by inorganic phosphate. The purified protein was used to raise a high-titre antiserum, which recognises a low-abundance 81 kDa protein in Synechocystis sp. PCC 6803 extracts. There was no apparent increase in expression of the 81 kDa protein when the cells were exposed to moderate salt stress, and SPS activity was very low in extracts from both unstressed and salt-stressed cells. These results and the lack of evidence for sucrose accumulation in Synechocystis sp. PCC6803 lead to the conclusion that expression of the sps gene plays no obvious role in adaptation to osmotic stress in this species.
Plant Mol Biol 1999 May
PMID:Cloning and expression of a prokaryotic sucrose-phosphate synthase gene from the cyanobacterium Synechocystis sp. PCC 6803. 1041 8


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