Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The staphylococcal beta-lactamase transposon Tn552 is a member of a novel group of transposable elements. The organization of genes in Tn552 resembles that of members of the Tn21 sub-group of Tn3 family transposons, which transpose replicatively by cointegrate formation and resolution. Thus, a possible resolution site ('resL') and a resolvase gene (tnpR or 'binL') have been identified. However, consistent with the fact that Tn552 generates 6 bp (rather than 5 bp) flanking direct repeats of target DNA, neither the putative transposase protein, nor the terminal inverted repeats of Tn552 are homologous to those of Tn3 elements. Tn552, like phage Mu and retroelements, is defined by the terminal dinucleotides 5' TG .. CA 3'. A naturally occurring staphylococcal plasmid, pI9789, contains a Tn552-derived resolution system ('resR-binR') that acts as a 'hotspot' for Tn552 transposition; insertion creates a segment of DNA flanked by inversely repeated resolution sites, one (resR) on pI9789 and the other (resL) on Tn552. The putative Tn552 resolvase, the most closely related of known resolvases to the homologous DNA invertases, initially was identified as a DNA invertase ('Bin') as a result of its ability to mediate efficient inversion of this segment in vivo.
EMBO J 1989 Sep
PMID:Characterization of the staphylococcal beta-lactamase transposon Tn552. 255 86

We have recently shown that secretion of invertase is not inhibited in the yeast Saccharomyces cerevisiae during mitosis, but continues, as during interphase. This is in contrast with the mammalian cell, where membrane traffic stops at the onset of prometaphase. Here we extend our findings by showing that the bulk of the cell surface glycoproteins and mannans, as well as the yeast pheromone alpha-factor, traverse the secretory pathway during mitosis. We show that the mitotic cells are able to carry out several types of post-translational modification of secretory proteins. (a) The secretory protein invertase was oligomerized and extensively glycosylated, (b) the N-glycan cores of bulk-cell surface mannans were extended with outer chains, (c) some N-glycans were phosphorylated, (d) the protein-bound O-glycans were extended up to tetramannosides, (e) prepro-ka-factor was proteolytically processed to alpha-factor molecules. We conclude that the secretory pathway in yeast remains fully functional throughout the cell cycle.
Eur J Biochem 1989 Sep 01
PMID:Post-translational modifications in mitotic yeast cells. 267 83

Factors for efficient synthesis of mRNA in vitro and its subsequent translation in cell free lysates from reticulocyte and wheat germ were studied using yeast invertase as a probe. Among various transcription systems tested, containing either SP6, T5, T7 or a bacterial synthetic consensus promoter, the T7 system was superior both from a quantitative and qualitative point of view. Transcription with SP6 polymerase, but not with the other enzymes, resulted in premature transcript termination, which is ascribed to a sensitivity of the SP6 polymerase towards a hairpin loop structure in the invertase coding region. In-frame fusion of the critical DNA sequence to a different gene promoted premature transcription termination of the resulting chimeric template, which in its original form is transcribed correctly. Transcripts with additional sequences 5' upstream of the natural translation start revealed a diminished protein synthesis presumably due to the presence of out of frame ATG codons. In contrast, no influence on translation was found when additional sequences at the 3' end were present or when the stop codon was missing. Capping of transcripts was essential for translation in wheat germ lysates, whereas protein synthesis in reticulocytes was only reduced in the absence of a cap. The influence of polyadenylation on translation was studied using transcripts with engineered poly(A) tracts of different size. Increasing poly(A) chain length abolished translation in vitro in both translation systems. Inhibition was poly(A)-specific and is discussed as interference of the poly(A) sequences with a crucial component(s) of the protein synthesis machinery.
Biochim Biophys Acta 1989 Sep 21
PMID:Requirements for efficient in vitro transcription and translation: a study using yeast invertase as a probe. 267 76

The gene encoding invertase (INV) has been cloned from Schwanniomyces occidentalis. The enzyme consists of 533 amino acids, 8 potential glycosylation sites and has a 45% identity with the invertase from Saccharomyces cerevisiae. The proenzyme has a 22 amino acid signal sequence that has a high alpha-helical transmembrane potential which differs significantly from that predicted for the Saccharomyces cerevisiae enzyme.
Curr Genet 1989 Sep
PMID:Cloning and sequence analysis of the gene encoding invertase from the yeast Schwanniomyces occidentalis. 268 29

A factor which may induce differentiation of intestinal epithelial cell lines in vitro was found in an acid extract of adult rat small intestine. The addition of a partially purified acetic acid extract of rat small intestine to IEC-18 cell culture dishes increased sucrase activity within 48 h. Thymidine incorporation markedly decreased within 24 h. Significant development of microvilli-like structures was observed on the acid extract-treated IEC-18 cells, compared with controls. This activity of rat acid extract was heat-stable and the apparent molecular weight of the factor was 400-800. These findings suggested that the factor may be related to the epithelial differentiation of rat small intestinal crypt cells.
FEBS Lett 1989 Sep 25
PMID:Differentiation of intestinal epithelial cell line (IEC-18) by an acid extract of rat small intestine. 279 86

Micrococcal nuclease digestion has been used to investigate some fine details of the chromatin structure of the yeast SUC2 gene for invertase. Precisely positioned nucleosomes have been found on a 2 kb sequence from the 3' non-coding region, and four nucleosomes also seem to occupy fixed positions on the 5' flank. Eleven nucleosomes lie on the coding region, although their positioning is not as precise as in the flanks. When the gene is derepressed, these latter nucleosomes adopt a more open conformation and so do two of the nucleosomes positioned on the 5' flank. A dramatic change occurs in the 3' flank, whose involvement in the structural transitions of chromatin upon gene activation is postulated. All the observed features are conserved when the gene is inserted in either a single copy centromeric plasmid or in a multicopy, 2 micron circle-based plasmid.
Nucleic Acids Res 1987 Sep 11
PMID:Fine analysis of the chromatin structure of the yeast SUC2 gene and of its changes upon derepression. Comparison between the chromosomal and plasmid-inserted genes. 282 86

Gastric and intestinal phenotypic expression in 37 surgically obtained primary signet ring cell carcinomas, five of their metastases to lymph nodes, and three signet ring cell carcinomas transplanted into nude mice were determined by biochemical, mucin, histochemical, and ultrastructural studies. Crude extracts of cancer tissues were used for measurements of pepsinogen isozymes, sucrase, aminopeptidase (microsomal), and alkaline phosphatase. Histochemical staining of mucin by paradoxical concanavalin A, the galactose oxidase-Schiff sequence and sialidase-galactose oxidase-Schiff, and the periodate-borohydride technique/potassium hydroxide/periodic acid-Schiff procedure was performed. The procedures allowed clear definition of pyloric gland, surface mucous, small and large intestinal goblet, and intestinal absorptive cell types. Of 40 specimens examined, 19 consisted entirely of gastric-type cells, and three entirely of intestinal-type cells. The others consisted of mixtures of gastric and intestinal-type cells. The observed high incidence of intestinal-type cells in signet ring cell carcinomas suggested that intestinal-type cells develop independently from intestinal metaplasia within signet ring cell carcinomas (diffuse-type gastric cancers), which probably originate from nonmetaplastic gastric mucosa.
Cancer Res 1986 Sep
PMID:Gastric and intestinal phenotypic expressions of human signet ring cell carcinomas revealed by their biochemistry, mucin histochemistry, and ultrastructure. 301

The Streptococcus mutans GS-5 gene, scrB, coding for sucrose 6-phosphate hydrolase activity has been cloned into Escherichia coli utilizing the bacteriophage replacement vector lambda L47.1. DNA sequences containing the gene were initially subcloned into the moderate-copy-number plasmid vector pLG339 to yield active subclones. However, due to the instability of the resultant chimeric plasmids, the gene was subsequently subcloned into the low-copy-number vector pOU61 to yield the stable hybrid plasmid pMH613. Both plasmids contain a 6.6-kilobase EcoRI fragment from strain GS-5 and express both hydrolase and sucrase activities. The relative position of the gene in the insert has been determined after Tn5 mutagenesis and deletion analysis. The cloned enzyme was purified to near homogeneity after gel filtration and anion-exchange chromatography, chromatofocusing, and preparative polyacrylamide gel electrophoresis. The purified enzyme displayed a molecular mass of 58 kilodaltons, which is significantly higher than the 48-kilodalton enzyme previously purified from S. mutans GS-5. These results suggest that processing of the hydrolase occurs in S. mutans.
Infect Immun 1986 Sep
PMID:Isolation and characterization of the sucrose 6-phosphate hydrolase gene from Streptococcus mutans. 301 64

In the present study, the protective effect of PGE2 on intestinal damage in indomethacin-treated adult rats was investigated. Ileal integrity was evaluated making use of different biochemical and histological parameters: activities of sucrase, maltase and diamine oxidase; concentrations of DNA, putrescine, spermidine and spermine; incorporation of 3H-thymidine into DNA; mitotic index and mucosal thickness. Results expressed per g of mucosal weight, showed that: maltase and diamine oxidase activities as well as DNA, spermidine and spermine concentrations decreased markedly in indomethacin-treated rats when compared to control rats; the decrease of maltase activity as well as DNA, spermidine and spermine concentration was less pronounced in PGE2-treated rats when compared to indomethacin-treated rats; 3H-thymidine incorporation into DNA and mitotic index values showed no significant variation in the course of different treatments; mucosal thickness increased strongly, in PGE2-protected rats. We suggest that PGE2 could protect the rat's intestinal mucosa against the effects of indomethacin through a trophic action on intestinal villi.
Life Sci 1987 Sep 07
PMID:Effect of prostaglandin E2 on the small intestine of indomethacin-treated rats. 311 78

We studied the binding of E. coli heat-stable enterotoxin (STa) to rat brush borders (BB) and to basolateral membranes (BLM) using a biologically active monoiodinated radioligand [( 125I]STa) and highly enriched BB and BLM preparations free of other significant organelle contamination. Binding of [125I]STa to BB was specific; time-, temperature-, and pH-dependent; saturable; and partially reversible. Nonlabeled toxin competitively inhibited the binding of radioligand to BB in a dose-related manner. Scatchard analysis revealed a single class of receptors with an apparent affinity constant of 8.7 +/- 1.5 X 10(8) l/mol. Binding was not affected by amino acids, sugars, and lectins. Proteolytic enzymes significantly decreased binding, although several did so by modifying the radioligand. Trypsin inhibited binding without modifying the radioligand thus supporting the proteinaceous nature of the receptor. Since the enrichment in binding activity in the BB over the homogenate was significantly lower than the enrichment in sucrase activity, we concluded that binding activity is probably associated with other membranous domains, but direct examination revealed no binding activity on basolateral membranes.
Dig Dis Sci 1987 Sep
PMID:Binding of E. coli heat-stable enterotoxin to rat intestinal brush borders and to basolateral membranes. 330 88


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