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)

1. Liver biopsies from two patients with the Dubin-Johnson-Sprinz syndrome were subjected to analytical subcellular fractionation by sucrose-density-gradient centrifugation and enzymic microassays. 2. A selective deficiency of mitochondrial superoxide dismutase has been demonstrated in these patients. 3. The significance of this enzyme deficiency is discussed in relation to the organelle pathology of the syndrome.
Clin Sci Mol Med 1978 May
PMID:The organelle pathology and demonstration of mitochondrial superoxide dismutase deficiency in two patients with Dubin--Johnson--Sprinz syndrome. 75 Jan 56

The high prevalence of glucose 6-phosphate dehydrogenase (G6PD) deficiency in African populations is due almost entirely to the enzyme variant A-, which differs from the wild-type G6PD B by two amino acid replacements, 68 Val-->Met and 126 Asn-->Asp. The non-deficient polymorphic variant G6PD A contains only the mutation 126 Asn-->Asp. The frequencies of the G6PD A and of the G6PD A- genes in parts of Africa are both about 0.2. The 68 Val-->Met mutation has not been found in a B background. This could be because the 68 Val-->Met mutation happened to arise in an A gene in the first instance, or because the 68 Val-->Met mutation alone is not sufficient to cause G6PD deficiency. We have approached this question by producing G6PD B, A, A-, and G6PD 68 Val-->Met in a bacterial expression system and analysing their biochemical properties. With each single mutation we found a slight decrease in both the specific activity and the yield of enzyme when compared to G6PD B. When both mutations were introduced together, there was a roughly additive effect on specific activity, but a much more drastic effect on enzyme yield (4% of normal). This synergistic effect was also demonstrated on thermal stability, especially at low NADP concentrations. Comparable results were produced when the replacement 119 Gln-->Glu was studied instead of 126 Asn-->Asp. We infer that the coexistence of the two mutations is responsible for enzyme deficiency in G6PD A- because they act synergistically in causing instability of the enzyme.
Hum Mol Genet 1992 Jun
PMID:Both mutations in G6PD A- are necessary to produce the G6PD deficient phenotype. 130 73

The clinical, neurophysiological, morphological and biochemical manifestation of eyes from Persian kittens affected with alpha-mannosidosis were studied. Clinically the disease is characterized by progressive corneal and lenticular opacification. In addition there is asymmetry in shape and latency of signal conductions which were demonstrated by visual evoked potential studies. Morphological and histochemical studies revealed vacuolization of various ocular cell types which stained positively with Concanavalia ensiformis agglutinin (Con A) and wheat germ agglutinin (WGA). Biochemical studies illustrated low activity of acid alpha-mannosidase in cultured keratocytes and abnormal storage of partially degraded oligosaccharides in these cells, in vitreous humor and lens. This comprehensive study of ocular alpha-mannosidosis demonstrates enzyme deficiency which leads to abnormal storage of oligosaccharides in affected cells and is manifested by morphological alterations and functional impairment.
Virchows Arch B Cell Pathol Incl Mol Pathol 1991
PMID:Clinical, neurophysiological, biochemical and morphological features of eyes in Persian cats with mannosidosis. 167 68

The isolation of a human cDNA encoding the multifunctional protein containing GAR synthetase, AIR synthetase, and GAR transformylase by functional complementation of purine auxotrophy in yeast has been reported. Chinese hamster ovary (CHO) cell mutant purine auxotrophs deficient in GAR synthetase (Ade-C) or AIR synthetase plus GAR transformylase (Ade-G) activities were transfected with this human GART cDNA subcloned into a mammalian expression vector. This restored 49-140% of the activities of GAR synthetase, AIR synthetase, and GAR transformylase in transfected cells when compared to wild-type CHO K1 parental cells. Study of one stably expressing transfectant, AdeC2, revealed that the human GART cDNA was incorporated into the CHO genome. The enzyme activities appear to be associated with an expressed protein of 110 kDa, very similar to that of purified human GART trifunctional enzyme. The Ade-C mutant shows reduced amounts of GART mRNA compared to CHO K1 and a protein of apparently reduced size, results consistent with the purine requirement and enzyme deficiency observed in the mutant. These experiments provide definitive evidence that the human GART cDNA encodes and can direct the production of active human GART trifunctional protein in mammalian cells. They also provide important evidence that the Ade-C and Ade-G mutants of CHO cells are defective in this gene.
Somat Cell Mol Genet 1991 Jul
PMID:Expression of a human cDNA encoding a protein containing GAR synthetase, AIR synthetase, and GAR transformylase corrects the defects in mutant Chinese hamster ovary cells lacking these activities. 188 37

Deficient arylsulfatase-A activity is diagnostic of a neurodegenerative human lysosomal storage disease, metachromatic leukodystrophy. Paradoxically, similar enzyme deficiency also occurs in normal individuals, who are known as being pseudo arylsulfatase-A deficient. We showed previously that this phenotype is associated with a structural gene mutation that produces an exceptionally labile enzyme. We now report on the nature and consequence of this mutation. When the mutant arylsulfatase-A is deglycosylated by endoglycosidase H, only one smaller molecular species was generated, instead of the two from the normal enzyme. This is consistent with the loss of one of the two N-linked oligosaccharide side chains known to be present on the wild-type enzyme. Quantitative analysis of mannose and leucine incorporation showed that the mutant enzyme incorporated two- to tenfold less mannose than the normal enzyme on a molar basis. This deficient glycosylation was specific to arylsulfatase-A. Another lysosomal enzyme not affected in this mutation, beta-hexosaminidase, was glycosylated normally in the mutant cells. The remaining single oligosaccharide side chain released from the mutant arylsulfatase-A by pronase digestion was normally processed to complex and high-mannose forms. However, the high-mannose side chains contained 30% fewer phosphorylated residues than those of the normal enzyme. Nevertheless, this reduced level of phosphorylation did not prevent targeting of the mutant enzyme to the lysosomes, a process normally mediated through phosphorylated mannose residues. In conclusion, pseudo arylsulfatase-A deficiency is a unique human mutation associated with reduced glycosylation and phosphorylation of a lysosomal enzyme with the loss of one of the two carbohydrate side chains. The mutation results in greatly reduced enzyme stability, thus indicating a role for oligosaccharides in maintaining enzyme stability within the degradative environment of the lysosomes. However, the residual catalytic activity or subcellular targeting of the mutant enzyme was not affected. These properties probably account for the benign clinical presentation of pseudo arylsulfatase-A deficiency.
Mol Cell Biochem 1990 Feb 09
PMID:Deficient glycosylation of arylsulfatase A in pseudo arylsulfatase-A deficiency. 196 15

We report here the isolation of a human cDNA encoding the first step in de novo purine biosynthesis, amidophosphoribosyltransferase (PRAT). The human PRAT cDNA was isolated by complementation of a Saccharomyces cerevisiae ade4 mutant deficient in PRAT enzymatic activity. The identity of the isolated cDNA, designated pAdeA-3, was confirmed by several independent methods. Genomic DNA sequences homologous to pAdeA-3 show coordinate segregation with the hypoxanthine nutritional requirement in Chinese hamster ovary (CHO) cell Ade-A-human hybrids, segregants of these hybrids, and irradiation reduction hybrids. The PRAT cDNA after insertion into a mammalian expression vector was capable of correcting the PRAT cDNA after insertion into a mammalian expression vector was capable of correcting the PRAT enzyme deficiency in CHO Ade-A mutants. This correction was monitored by both cell-free PRAT assays and in vivo phosphoribosylformylglycinamide (FGAR) accumulation studies. FGAR accumulation is a classic method for assessment of the early steps of purine nucleotide biosynthesis. Two of the isolated transformants, designated PRAT-1 and PRAT-2, exhibited 22% and 53%, respectively, of wild-type CHO K1 PRAT enzymatic activity using a cell-free enzyme assay. These same two transformants plus an additional transformant, designated PRAT-13, showed FGAR accumulations of 150%, 260%, and 140%, respectively, compared to the levels of accumulation seen in CHO K1. Transformants PRAT-1 and PRAT-2 both contained a mRNA species recognized by the PRAT cDNA of identical size to a mRNA species in human fibroblasts homologous to the PRAT cDNA. This observation, along with the functionality of the cDNA in both yeast and CHO cells deficient in PRAT activity, suggests the isolated cDNA is full length.
Somat Cell Mol Genet 1991 May
PMID:Isolation of a human cDNA encoding amidophosphoribosyltransferase and functional complementation of a CHO Ade-A mutant deficient in this activity. 204 42

Several mutations in the human lipoprotein lipase (LPL) gene have been shown to underlie LPL deficiency. These mutations occur in patients who are mainly of European descent, and comprise a single base transition causing a premature stop codon, four separate amino acid substitutions and two large gene rearrangements. Together they account for approximately 40% of the LPL alleles in a cohort of 50 patients whose DNA has been examined in this laboratory. We now report on a new mutation in exon 3 of the LPL gene from a South African subject of South-east Asian extraction. This mutation comprises a six base-pair insertion at the site of a single base deletion. The net insertion of five base-pairs at amino acid positions 102 to 103 causes a shift in the reading frame, generating 44 amino acid residues of random sequence and a premature stop codon within exon 4. This mutation is predicted to result in the synthesis of a markedly truncated protein and is the cause of the enzyme deficiency in our patient.
Mol Biol Med 1990 Dec
PMID:Frameshift mutation in exon 3 of the lipoprotein lipase gene causes a premature stop codon and lipoprotein lipase deficiency. 207 51

Retroviral vectors were used to transfer genes efficiently into rat and dog myoblasts in primary cultures under conditions which permitted the transduced myoblasts to differentiate into myotubes expressing the transferred genes. The transduced myotubes expressed normal markers of differentiation and were morphologically indistinguishable from uninfected myotubes. Retroviral vector-mediated gene transfer was also used to correct a genetic enzyme deficiency in mutant canine muscle cells.
Mol Cell Biol 1990 Jun
PMID:Genes transferred by retroviral vectors into normal and mutant myoblasts in primary cultures are expressed in myotubes. 216 May 98

We have compared the pattern of lectin staining with the ultrastructural features of kidneys from normal cats and 19 cats with 6 different lysosomal storage diseases. The diseases studied include GM1 and GM2 gangliosidosis, mucopolysaccharidosis (MPS)-I and MPS-VI, sphingomyelin-lipidosis (i.e., Niemann-Pick disease) and mannosidosis. Ten different biotinylated lectins were used as histochemical probes for carbohydrate residues and avidin-biotin-peroxidase complex as visualant. Concanavalia ensiformis agglutinin (Con A) stained mesangial cells in all storage diseases but GM1, epithelial cells in sphingomyelin-lipidosis and mannosidosis, endothelial cells in GM1 and mannosidosis and Bowman's capsule cells in all but GM2. Griffonia simplicifolia agglutinin I (GS-I) stained the glomerular endothelium in all six diseases, but not in control kidneys. Ricinus communis agglutinin-I (RCA-I) stained the glomerular epithelium only in GM1 and MPS-I. Succinylated wheat germ agglutinin (SWGA) stained the glomerular endothelium and epithelium in mannosidosis, and the glomerular epithelium and Bowman's capsule in MPS-I. Ultrastructure studies demonstrated an accumulation of oligosaccharides in cases of mannosidosis and GM1 gangliosidosis, a mixture of oligosaccharides and lipids in MPS-I, MPS-VI and GM2 gangliosidosis and only lipid storage in sphingomyelin lipidosis. These studies show that morphologic and histochemical changes are manifested in some kidney cell types in lysosomal storage diseases, even though the enzyme deficiency occurs in all cell types. Furthermore, we show that the nature of the undegraded stored material is complex and that other factors, such as rate of membrane turn over, membrane composition, and cell function may influence the amount and nature of the "stored" material.
Virchows Arch B Cell Pathol Incl Mol Pathol 1987
PMID:Lectin histochemistry and ultrastructure of feline kidneys from six different storage diseases. 289

A biochemical analysis of mutants altered for nitrate assimilation in Neurospora crassa is described. Mutant alleles at each of the nine nit (nitrate-nonutilizing) loci were assayed for nitrite reductase activity, for three partial activities of nitrate reductase, and for nitrite reductase activity. In each case, the enzyme deficiency was consistent with data obtained from growth tests and complementation tests in previous studies. The mutant strains at these nit loci were also examined for altered regulation of enzyme synthesis. Such experiments revealed that mutations which affect the structural integrity of the native nitrate reductase molecule can result in constitutive synthesis of this enzyme protein and of nitrite reductase. These results provide very strong evidence that, as in Aspergillus nidulans, nitrate reductase autogenously regulates the pathway of nitrate assimilation. However, only mutants at the nit-2 locus affect the regulation of this pathway by nitrogen metabolite repression.
Mol Gen Genet 1981
PMID:Biochemical analysis of mutants defective in nitrate assimilation in Neurospora crassa: evidence for autogenous control by nitrate reductase. 646 Jan 56


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