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

The complete sequence of the 6 kb cDNA and the 5' genomic structure are reported for the gene coding for the human intestinal brush border hydrolase sucrase-isomaltase. The human sucrase-isomaltase cDNA shows a high level of identity (83%) with that of the rabbit enzyme, indicating that the protein shares the same structural domains in both species. In addition to the previously reported homology with lysosomal alpha-glucosidase, the sucrase and isomaltase subunits also appear to be homologous to a yeast glucoamylase. A 14 kb human genomic clone has been isolated which includes the first three exons and the first two introns of the gene, as well as 9.5 kb 5' to the major start site of transcription. The first exon comprises 62 bp of untranslated sequence and the second starts exactly at the initiation ATG codon. Typical CAAT and TATA boxes are seen upstream of the first exon. A genetic polymorphism is described which involves a PstI site in the second intron. Southern blotting, sequencing and mRNA studies indicate that the structures of the sucrase-isomaltase gene and its mRNA are unaltered in the two human colon cancer cell lines Caco-2 and HT-29 in comparison with normal human small intestine.
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PMID:Sequence of the complete cDNA and the 5' structure of the human sucrase-isomaltase gene. Possible homology with a yeast glucoamylase. 135 58

A genomic clone (lambda ScG7) from Saccharomyces cerevisiae encoded a 650-nucleotide poly(A)-containing [poly(A)+] RNA that was about 50 times more abundant in MATa cells that had been exposed to the peptide pheromone alpha-factor than in untreated cells. This RNA was transcribed from a cluster of repetitive sequences: both intact and truncated delta and sigma elements adjacent to a tRNATrp gene. Strand-specific probes indicated that this RNA initiated within an intact sigma element and contained sigma sequences at its 5' end. MATa cells produced two other prominent poly(A)+ RNAs (500 and 5,300 bases) in response to alpha-factor that were homologous to the same strand of sigma but transcribed from other locations in the genome. Induction of the sigma-related transcripts was rapid, was not blocked by inhibition of protein synthesis, required a functional receptor (STE2 gene product), and hence appeared to be a primary response to pheromone. Pulse-labeling confirmed that accumulation of sigma RNA following alpha-factor administration was accounted for by an increase in its rate of transcription. The sigma RNAs also were induced in MAT alpha cells that had been treated with a-factor, but were not present at significant levels in MATa/MAT alpha diploids. In MATa cells transformed with a plasmid in which the lambda ScG7 sigma element was inserted just upstream of a gene coding for the intracellular form of invertase (SUC2) lacking its own promoter, a new poly(A)+ RNA (2.2 kilobases) appeared in response to alpha-factor that hybridized to both sigma and SUC2 probes, and intracellular invertase activity was elevated about 10-fold within 30 min. Primer extension showed that transcription from the hybrid gene initiated exclusively within the sigma sequence (117 nucleotides from the 3' end of the element).
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PMID:The yeast repeated element sigma contains a hormone-inducible promoter. 354 81

Carrot cell wall beta-fructosidase, previously purified and cloned, is encoded by a single, wound- and pathogen-inducible gene. The developmental regulation of the gene was studied by determining the steady-state mRNA levels in different organs during carrot development: cell wall beta-fructosidase mRNA was detected in roots and leaves of young plants but not during tap root development. A genomic clone was isolated and characterized. The transcription start site was determined by primer extension analysis. Inspection of the promoter sequence (1488 bp) revealed the presence of sequences with high homology to cis-acting elements for the regulation of plant genes by wounding and infection. The 5'-regulatory sequence was fused to the reporter gene beta-glucuronidase (GUS) and tested in a transient expression assay with carrot suspension cells and wounded carrot root tissue (aged disks of carrot roots). The expression of the GUS gene in the transfected cells proved that the isolated promoter was functional. In transgenic tobacco plants containing the cell wall beta-fructosidase promoter fused to GUS, the reporter gene was predominantly expressed in the shoot and root meristems of young seedlings. No GUS expression was detected in mature tobacco plants, showing that the development-specific regulation of the cell wall beta-fructosidase promoter seen in carrot was maintained in tobacco plants. In contrast, expression of the GUS reporter gene in transgenic tobacco was not wound inducible. To analyze the functional organization of the cell wall beta-fructosidase promoter, a 5'-deletion series was generated and tested in a transient expression assay in protoplasts of Nicotiana plumbaginifolia. Two regions containing putative silencer elements were identified. A comparison of these regions with known silencer elements identified in both regions one copy of the negative dominant cis-acting element found in a chalcone synthase promoter of petunia.
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PMID:Molecular characterization of the gene for carrot cell wall beta-fructosidase. 822 Apr 95

Sink strength optimizes sucrose import, which is fundamental to support developing seed grains and increase crop yields, including those of rice (Oryza sativa). In this regard, little is known about the function of vacuolar invertase (VIN) in controlling sink strength and thereby seed size. Here, in rice we analyzed mutants of two VINs, OsVIN1 and OsVIN2, to examine their role during seed development. In a phenotypic analysis of the T-DNA insertion mutants, only the OsVIN2 mutant osvin2-1 exhibited reduced seed size and grain weight. Scanning electron microscopy analysis revealed that the small seed grains of osvin2-1 can be attributed to a reduction in spikelet size. A significant decrease in VIN activity and hexose level in the osvin2-1 spikelets interfered with spikelet growth. In addition, significant reduction in starch and increase in sucrose, which are characteristic features of reduced turnover and flux of sucrose due to impaired sink strength, were evident in the pre-storage stage of osvin2-1 developing grains. In situ hybridization analysis found that expression of OsVIN2 was predominant in the endocarp of developing grains. A genetically complemented line with a native genomic clone of OsVIN2 rescued reduced VIN activity and seed size. Two additional mutants, osvin2-2 and osvin2-3 generated by the CRISPR/Cas9 method, exhibited phenotypes similar to those of osvin2-1 in spikelet and seed size, VIN activity, and sugar metabolites. These results clearly demonstrate an important role of OsVIN2 as sink strength modulator that is critical for the maintenance of sucrose flux into developing seed grains.
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PMID:The Role of Rice Vacuolar Invertase2 in Seed Size Control. 3160 84