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)

Preneoplastic and neoplastic hepatic lesions were induced in male Sprague-Dawley rats by oral administration of N-nitrosomorpholine (NNM) for 7 weeks at a concentration of 200 mg/l of drinking-water (stop model). Using a laser dissection technique and biochemical microanalysis, the activity of the lysosomal enzyme alpha-glucosidase was measured in glycogen storage foci emerging early, and in mixed or basophilic cell populations (foci and carcinomas) appearing later during hepatocarcinogenesis. In the liver tissue of normal appearance in both untreated controls and NNM-treated animals a slight gradient of alpha-glucosidase activity was observed leading from relatively high activities in zone 1 to lower activities in zone 3 of the liver lobule. In preneoplastic glycogen storage foci a considerable relative reduction in alpha-glucosidase activity was detected, suggesting that a decrease in the hydrolytic glycogen degradation contributes to the disturbance in phosphorylytic glycogen breakdown observed earlier in the majority of the glycogenotic foci. In contrast with glycogen storage foci, mixed and basophilic cell foci and particularly hepatocellular carcinomas showed a marked increase in alpha-glucosidase activity compared with that of normal liver tissue. The gradual enhancement in enzyme activity appeared to be closely related to the reduction in glycogen initially stored in excess during the later stages of hepatocarcinogenesis. The results support the concept that a fundamental shift in carbohydrate metabolism is characteristic of neoplastic transformation of hepatocytes.
Virchows Arch B Cell Pathol Incl Mol Pathol 1989
PMID:Biochemical microanalysis of alpha-glucosidase activity in preneoplastic and neoplastic hepatic lesions induced in rats by N-nitrosomorpholine. 256 85

Using standard growth conditions (LB medium, 37 degrees C, induction with 5 mM IPTG) yeast alpha-glucosidase PI expressed under the control of the regulated tac-hybrid promoter results in the synthesis of insoluble aggregated alpha-glucosidase granules in Escherichia coli. Under these conditions active soluble alpha-glucosidase amounts to less than 1% of the heterologously produced protein. However, the amount of soluble active alpha-glucosidase was dramatically increased when the strong tac-hybrid promoter was to a limited extent induced. This was achieved at concentrations of 0.01 mM IPTG or of 1% lactose or lower in a lactose-permease deficient host strain containing the lacIq repressor gene on an R-plasmid. The formation of active soluble alpha-glucosidase was almost 100% when E. coli cells induced in this manner were cultivated under conditions that reduced growth rate, i.e. at decreased temperature, extreme pH values or in minimal and complete media supplemented with different carbon sources.
Mol Gen Genet 1989 Mar
PMID:Control of formation of active soluble or inactive insoluble baker's yeast alpha-glucosidase PI in Escherichia coli by induction and growth conditions. 265 69

Normal arterial foci which take up Evans blue dye (EBD) in vivo are believed to represent atherosclerosis-prone, hemodynamically stressed foci compared to areas which exclude dye. We have used the rabbit EBD model to examine focal aortic hydrolases of blue areas versus white areas, and we report herein significant focal variations of hydrolase activities. Enzymes measured included neutral alpha-glucosidase, N-acetyl-beta-glucosaminidase, alpha-mannosidase, acid alpha-glucosidase, beta-galactosidase, beta-glucuronidase, cathepsin C, and acid cholesteryl esterase (ACE); specific activities were expressed on the basis of tissue DNA. In correlative areas of EBD uptake in normal rabbit aortic arch, ACE activity averaged 17% higher and cathepsin C activity averaged 37% lower than activities of areas free of EBD in the descending thoracic aorta (P less than 0.02). None of the glycosidases studied differed significantly between blue and white aortic areas. These findings indicate that discrete, intrinsic differences of hydrolytic enzyme activities exist in the normal rabbit aorta in areas delineated by in vivo EBD uptake, areas recognized as lesion-prone vs lesion-resistant.
Exp Mol Pathol 1989 Aug
PMID:Intrinsic focal variations of rabbit aortic hydrolase activities. 276 19

Maltose fermentation in Saccharomyces carlsbergensis is dependent upon the MAL6 locus. This complex locus is composed of the MAL61 and MAL62 genes, which encode maltose permease and maltase, respectively, and a third gene, MAL63, which codes for a trans-acting positive regulatory product. In wild-type strains, expression of the MAL61 and MAL62 mRNAs and proteins is induced by maltose and induction is dependent upon the MAL63 gene. Mutants constitutively expressing the MAL61 and MAL62 gene products have been isolated in mal63 backgrounds, and the mutations which have been analyzed map to a fourth MAL6-linked gene, MAL64. Cloning and characterization of this new gene are described in this report. The results revealed that the MAL64-C alleles present in constitutive strains encode a trans-acting positive function required for constitutive expression of the MAL61 and MAL62 gene products. In inducible strains, the MAL64 gene is dispensable, as deletion of the gene had no effect on maltose fermentation or maltose-regulated induction. MAL64 encoded transcripts of 2.0 and 1.4 kilobase pairs. While both MAL64 mRNAs were constitutively expressed in constitutive strains, they were maltose inducible in wild-type strains and induction was dependent upon the MAL63 gene. The MAL63 and MAL64 genes are at least partially structurally homologous, suggesting that they control MAL61 and MAL62 transcript accumulation by similar mechanisms.
Mol Cell Biol 1988 Mar
PMID:Constitutive expression of the maltose fermentative enzymes in Saccharomyces carlsbergensis is dependent upon the mutational activation of a nonessential homolog of MAL63. 283 55

Certain effects of cyclic 3',5'-AMP administration on the lysosomes of newborn rat hepatocytes were studied using biochemical assays, electron microscopy, and quantitative morphometry. Cyclic AMP produced accelerations of postnatal hyaloplasmic glycogen breakdown and lysosomal glycogen breakdown, and an increase in activity of the lysosomal enzyme acid alpha-1,4-glucosidase (maltase). Ergotamine, a known antagonist of the effects of cyclic AMP, produced inhibitions of postnatal hyaloplasmic glycogen breakdown and lysosomal glycogen breakdown. Cyclic AMP increased while ergotamine decreased the volume of lysosomes. The results support the postulate that the catabolism of lysosomal glycogen is controlled by those agents that regulate the catabolism of hyaloplasmic glycogen (O. B. Kotoulas and M. J. Phillips, Amer. J. Pathol. (1971) 63, 1-17; O. B. Kotoulas et al., Amer. J. Pathol. (1971) 63, 23-36). Control is mediated by changes in the activity of the lysosomal enzyme acid alpha-1,4-glucosidase. Lysosomes actively participate in the degradation of hepatocellular glycogen.
J Ultrastruct Mol Struct Res
PMID:The effects of cyclic 3',5'-AMP on the lysosomes of newborn rat hepatocytes. 283 84

We determined the complete nucleotide sequence of the yeast MAL6R gene from the Saccharomyces carlsbergensis MAL6 locus. The MAL6R gene encodes a transacting protein required for the inducible, coordinate expression of the two divergently transcribed structural genes, MAL6T (maltose permease), and MAL6S (maltase) at this locus. The transcription initiation sites for MAL6R were determined by primer extension experiments. The MAL6R gene contains an open reading frame of 473 amino acids with a calculated Mr of 54,892. The N-terminus of the deduced protein contains an amino acid sequence isologous to a consensus sequence for cysteine-zinc associated DNA binding fingers found in other fungal DNA binding proteins. The MAL6R gene was mapped to chromosome VIII by using OFAGE (orthagonal field alternating gel electrophoresis) gels and hybridization with specific chromosome and MAL6 probes.
Mol Gen Genet 1988 Jul
PMID:Primary structure of the regulatory gene from the MAL6 locus of Saccharomyces carlsbergensis. 285 10

We have physically and functionally identified three genes at the MAL6 locus of Saccharomyces carlsbergensis. Using multicopy yeast plasmid vectors, we have subcloned various segments of the entire MAL6 locus. The functional characterization of the MAL6 subcloned regions was determined by (1) analyzing biochemically the levels of MAL-encoded proteins (maltase [alpha-D-glucosidase, E.C. 3.2.1.20] and maltose transport protein) in cells transformed with various MAL6 subclones, and (2) testing the ability of the subclones to complement the maltose fermentation defects of well characterized Mal- mutants in the highly homologous MAL1 locus. The physical homology between MAL6 and MAL1 is in part demonstrated by the gene disruption of MAL1 using subcloned MAL6 DNA sequences. The results demonstrate that the MAL6 locus is a complex of at least three genes: MAL6R, MAL6T and MAL6S. These genes specify, respectively, a regulatory function, a maltose transport activity (presumably the maltose permease) and the structural gene for maltase. The functional organization of the MAL6 locus is thus identical to that which we had previously determined by mutational analysis for the MAL1 locus.
Mol Gen Genet 1985
PMID:Organization of the MAL loci of Saccharomyces. Physical identification and functional characterization of three genes at the MAL6 locus. 299 4

We describe the isolation of a 22.6-kilobase fragment of DNA containing the MAL1 locus of Saccharomyces cerevisiae. Our results demonstrate that the MAL1 locus, like the MAL6 locus, is a complex locus containing three genes. These genes were organized similarly to their MAL6 counterparts. We refer to them as MAL11, MAL12, and MAL13 and show that they are functionally homologous to the MAL61 (encoding maltose permease), MAL62 (encoding maltase), and MAL63 (encoding the positive regulator) genes of the MAL6 locus. Transcription from each of the three genes was analyzed in a strain carrying the undisrupted MAL1 locus and in strains carrying single disruptions in each of the MAL1 genes. The MAL1 and MAL1 loci were found to be highly sequence homologous and conserved throughout the region containing these three genes. The strain used to isolate the MAL1 locus also carried the tightly linked SUC1 gene. The SUC1 gene was found to be located on the same 22.6-kilobase fragment containing the MAL1 locus and 5 kilobases from the 3' end of the MAL12 gene. The meaning of these results with regard to the mechanism of regulation of maltose fermentation is discussed.
Mol Cell Biol 1986 Nov
PMID:Structural and functional analysis of the MAL1 locus of Saccharomyces cerevisiae. 302 17

The expression of the maltase (MALS) and the maltose permease (MALT) genes in Saccharomyces species is coregulated at the transcriptional level; they are coordinately induced by maltose in the presence of a positively acting regulatory (MALR) gene and carbon catabolite repressed by glucose. We generated a series of deletions in the upstream region of the MAL6S gene to examine the regulatory elements in detail. The results showed that inducible expression by maltose was lost when the region between 320 and 380 base pairs upstream of the translation initiation codon was deleted. This region contained an imperfect inverted repeat sequence (-361 to -327) or four copies of short direct repeats that might serve as components of the upstream activation site (UASM) for the maltase gene, or both. When a stretch of T-rich sequence (-253 to -237) was deleted, the susceptibility of the maltase gene to carbon catabolite repression was affected.
Mol Cell Biol 1987 Jul
PMID:Upstream regulatory regions controlling the expression of the yeast maltase gene. 330 77

Mutations in the SSN6 gene suppress the invertase derepression defect caused by a lesion in the SNF1 protein kinase gene. We cloned the SSN6 gene of Saccharomyces cerevisiae and identified its 3.3-kilobase poly(A)-containing RNA. Disruption of the gene caused phenotypes similar to, but more severe than, those caused by missense mutations: high-level constitutivity for invertase, clumpiness, temperature-sensitive growth, alpha-specific mating defects, and failure to homozygous diploids to sporulate. In contrast, the presence of multiple copies of SSN6 interfered with derepression of invertase. An ssn6 mutation was also shown to cause glucose-insensitive expression of a GAL10-lacZ fusion and maltase. The mating defects of MAT alpha ssn6 strains were associated with production of two a-specific products, a-factor and barrier, and reduced levels of alpha-factor; no deficiency of MAT alpha 2 RNA was detected. We showed that ssn6 partially restored invertase expression in a cyr1-2 mutant, although ssn6 was clearly not epistatic to cyr1-2. We also determined the nucleotide sequence of SSN6, which is predicted to encode a 107-kilodalton protein with stretches of polyglutamine and poly(glutamine-alanine). Possible functions of the SSN6 product are discussed.
Mol Cell Biol 1987 Oct
PMID:Molecular analysis of SSN6, a gene functionally related to the SNF1 protein kinase of Saccharomyces cerevisiae. 331 83


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