Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.6.1 (sulfatase)
3,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lysosomal removal of the sulfate moiety from sulfatide requires the action of two proteins, arylsulfatase A and sphingolipid activator protein-1 (SAP-1). Recently, patients have been identified who have a variant form of metachromatic leukodystrophy which is characterized by mutations in the gene coding for SAP-1, which is also called "prosaposin." All of the mutations characterized in these patients result in (a) deficient mature SAP-1, as determined by immunoblotting after SDS-PAGE of tissue and cell extracts, and (b) decreased ability of cultured skin fibroblasts to metabolize endocytosed [14C]-sulfatide. We now report the insertion of the full-length prosaposin cDNA into the Moloney murine leukemia virus-derived retroviral vector, pLJ, and the infection of cultured skin fibroblasts from a newly diagnosed and molecularly characterized patient with SAP-1 deficiency. The cultured cells infected with the prosaposin cDNA construct now show both production of normal levels of mature SAP-1 and completely normal metabolism of endocytosed [14C]-sulfatide. These studies demonstrate that the virally transferred prosaposin cDNA is processed normally and is localized within lysosomes, where it is needed for interaction between sulfatide and arylsulfatase A. In addition, normal as well as mutant sequences can now be found by allele-specific oligonucleotide hybridization of PCR-amplified genomic DNA by using exonic sequences as primers.
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PMID:Correction of sulfatide metabolism after transfer of prosaposin cDNA to cultured cells from a patient with SAP-1 deficiency. 135 Aug 85

Examination of the role of carbohydrates in specific recognition between spermatozoa and zona pellucida has focussed on understanding the interaction of sperm hydrolases or lectin-like molecules with zona pellucida ligands. To elucidate the role of specific spermatozoan hydrolases in gamete interaction, rabbit testis beta-galactosidase and arylsulfatase A were purified, characterized, and localized in spermatozoa. beta-Galactosidase and arylsulfatase A co-purified after affinity, size, or reverse-phase chromatography. N-Terminal amino acid analysis and enzymatic characterization suggested that neither enzyme is a testis-specific isozyme. Size chromatography indicated that both enzymes aggregated into macromolecular complexes at pH 4.0, while both dissociated at pH 8.0. beta-Galactosidase and arylsulfatase A co-localized on the sperm surface and in the acrosome and postacrosomal regions of spermatozoa. Throughout the zona-induced acrosome reaction, both enzymes remained associated with the detached acrosomal cap and postacrosomal region of acrosome-reacted spermatozoa. Because the acrosome is an acidic subcellular compartment, internal beta-galactosidase and arylsulfatase A are probably aggregated in acrosome-intact spermatozoa and dissociate as they are exposed to pH increases during the acrosome reaction.
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PMID:Characterization of rabbit testis beta-galactosidase and arylsulfatase A: purification and localization in spermatozoa during the acrosome reaction. 135 47

The correct intracellular sorting of lysosomal enzymes such as arylsulfatase A depends on the presence of mannose 6-phosphate residues on high mannose type oligosaccharides. The arylsulfatase A cDNA contains three potential N-glycosylation sites, two of which are utilized. We have mutated one or two of the N-glycosylation sites and analyzed the glycosylation, phosphorylation, and intracellular sorting of the mutant arylsulfatase A polypeptides. The results show that each of the three glycosylation sites (I, II, and III) can be glycosylated, but glycosylation at sites I and II is mutually exclusive. In mutants with one oligosaccharide side chain at positions I, II, or III all side chains can acquire mannose 6-phosphate residues irrespective of their location. This demonstrates spatial flexibility of the phosphotransferase, which specifically recognizes lysosomal enzymes and initiates the addition of mannose 6-phosphate residues on oligosaccharide side chains. However, these mutants have different intracellular sorting efficiencies and seem to use different (mannose 6-phosphate receptor-dependent and -independent) sorting pathways.
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PMID:In vitro mutagenesis of potential N-glycosylation sites of arylsulfatase A. Effects on glycosylation, phosphorylation, and intracellular sorting. 135 93

Arylsulfatase A purified from human placenta contained an unreported component with an apparent molecular mass of 7 kDa in addition to the two known components with apparent molecular masses of 58 and 50 kDa. The detailed relationship between the 58 kDa component and the 50 kDa component is as yet unknown. The present study was undertaken to define the structure of the subunits of the sulfatase. The N-terminal sequence of the 50 kDa component was identical to that of the 58 kDa component. Furthermore, the peptide maps of the 50 kDa component, which was separately digested with trypsin and Achromobacter proteinase I, were quite similar to those of the 58 kDa one. Through sequence analysis of the incompatible peaks in the peptide maps, the 50 kDa component was found to lack a sequence from Val-445 to the C-terminus. On the other hand, the N-terminal sequence of the 7 kDa component began with Ala-448, though there was a minor sequence commencing with Thr-449. These observations suggest that the 50 and 7 kDa components were produced by limited proteolysis near the C-terminus of the 58 kDa component. Through analysis using unreducing SDS-PAGE, the 58 and the 7 kDa components were found to be linked by disulphide bonds. Arylsulfatase A purified from human liver was also composed of the same subunits as the placental one. This finding suggests that human arylsulfatase A undergoes similar proteolytic processing regardless of the tissue involved.
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PMID:Proteolytic processing of human lysosomal arylsulfatase A. 135 93

We report on a new allele at the arylsulfatase A (ARSA) locus causing late-onset metachromatic leukodystrophy (MLD). In that allele arginine84, a residue that is highly conserved in the arylsulfatase gene family, is replaced by glutamine. In contrast to alleles that cause early-onset MLD, the arginine84 to glutamine substitution is associated with some residual ARSA activity. A comparison of genotypes, ARSA activities, and clinical data on 4 individuals carrying the allele of 81 patients with MLD examined, further validates the concept that different degrees of residual ARSA activity are the basis of phenotypical variation in MLD.
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PMID:Late-onset metachromatic leukodystrophy: molecular pathology in two siblings. 135 40

We report on a 3-year-old boy with a terminal deletion of 22q. The activity of alpha-N-acetylgalactosaminidase was normal while arylsulfatase A activity was reduced. Molecular analysis demonstrated the lack of paternal alleles of D22S45 and D22S55.
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PMID:Cytogenetic, biochemical, and molecular analyses of a 22q13 deletion. 135 66

The mannose 6-phosphate (Man6P) residues that are necessary for the targeting of newly synthesized lysosomal proteins are dephosphorylated after delivery of lysosomal proteins to lysosomes. To examine the role of lysosomal acid phosphatase (LAP) for the dephosphorylation of Man6P residues in lysosomal proteins, the phosphorylation of endogenous lysosomal proteins and of internalized arylsulfatase A was analyzed in mouse L-cells that overexpress human LAP. Non-transfected L-cells dephosphorylate endogenous lysosomal proteins slowly (half time approximately 13 h) as well as internalized arylsulfatase A. A more than 100-fold overexpression of LAP in these cells did not affect the dephosphorylation rate. Control experiments showed that the internalized arylsulfatase A and overexpressed LAP partially colocalize and that under in vitro conditions purified LAP does not dephosphorylate arylsulfatase A. Taken together, these results indicate that LAP is not the mannose 6-phosphatase that dephosphorylates lysosomal proteins after their delivery to lysosomes.
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PMID:Lysosomal acid phosphatase is not involved in the dephosphorylation of mannose 6-phosphate containing lysosomal proteins. 135 23

Metachromatic leukodystrophy (MLD) is a neurologically devastating autosomal recessive disorder in humans associated with deficient arylsulfatase A activity. However, clinically normal individuals described as being pseudo-arylsulfatase-A deficient also demonstrate the same deficiency. Genotypically, they may be homozygous for the pseudodeficiency mutation (associated with 2 A-->G transitions in the cDNA of arylsulfatase A) or heterozygous with one pseudodeficiency and one MLD allele. Using as examples 2 families in which the pseudo deficiency condition occurs either independently or together with MLD, we demonstrate the utility of a proposed diagnostic protocol to provide complete genotype identification of individuals suffering from arylsulfatase A deficiency. Patient fibroblasts are extracted for DNA and a cytoplasmic fraction, which is used for arylsulfatase A enzyme assay. This will identify an arylsulfatase A-deficient group, which is further analyzed electrophoretically. Cells from the clinically affected patients with MLD are completely deficient in arylsulfatase A activity, whereas those from the pseudodeficient individuals demonstrate a characteristic residual arylsulfatase A activity detectable only after electrophoresis. Within this pseudodeficient group, gene amplification of DNA specific for the A-->G mutations will distinguish between those who are homozygous for the pseudodeficiency allele and those who are compound heterozygous for the pseudodeficiency and MLD alleles. This protocol of complete genotype identification requires only about 10(6) fibroblasts (1 x 100 mm dish) and 2 days to complete. Such variant-specific genotype identification increases accuracy and prognostic value of the diagnosis. It will likely become the preferred choice for diagnosis of genetic disease in the future as more variant-specific mutations are identified at the molecular level.
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PMID:Diagnosis of arylsulfatase A deficiency. 135 70

Sperm cells and seminal plasma of various mammals contain high levels of arylsulfatase. In the present study, we investigated the composition of soluble AS in these compartments of boar semen by analysing sperm cells and seminal plasma using anion-exchange chromatography. Seminal plasma contained both arylsulfatase B (2.4 units per ml), an enzyme which desulfates sulfoglycosaminoglycans and probably sulfoglycoproteins, and arylsulfatase A (10.2 units per ml), an enzyme which desulfates sulfogalactolipids. Sperm cells contained only arylsulfatase A, which differed biochemically from the extracellular arylsulfatase A of seminal plasma (2.6 units per ml). Both types of arylsulfatase A desulfate seminolipid, the natural sulfolipid substrate in sperm, as well as two brain sulfatides. The possible physiological consequences of the presence of extracellular arylsulfatases in seminal plasma for spermatozoa are discussed.
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PMID:Characterization of three arylsulfatases in semen: seminolipid sulfohydrolase activity is present in seminal plasma. 135 1

Sulfatide excretion in urine and arylsulfatase A (ASA) activity in leukocytes were determined in 10 homozygotes of metachromatic leukodystrophy (MLD), 7 obligate and 5 facultative MLD heterozygotes, 6 low ASA subjects (not related to MLD homozygotes), and in 9 controls. As compared to controls (sulfatides: 0-2 nmol/mg lipid; ASA: 101-287 nmol p-nitrocatechol/mg protein/hr), MLD homozygotes displayed highly increased sulfatide excretions (27-280 nmol) and low residual ASA activities (0-13 nmol). Of 12 MLD heterozygotes (ASA: 18-87 nmol) 10 showed increased sulfatides (3-24 nmol). All heterozygotes with ASA activity < 60 nmol (n = 8) had elevated sulfatide excretions (4-24 nmol). Thus, reduction of ASA activity below 40% of the mean value of controls seems to be the critical threshold for elevated sulfatide excretion in MLD heterozygotes. The low ASA subjects (ASA in the heterozygote range) excreted sulfatides in the control range, even those with ASA activities < 60 nmoles (n = 3; including a definite homozygote for ASA-pseudodeficiency; ASA:25 nmol). Statistical evaluation of sulfatide excretion and ASA activity in all subjects (n = 37) revealed a significant inverse relation (Spearman rank correlation; R = 0.8278, P < 0.001). The finding of elevated sulfatide excretion in certain MLD heterozygotes might point to increase of sulfatides also in the nervous system.
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PMID:Elevated sulfatide excretion in heterozygotes of metachromatic leukodystrophy: dependence on reduction of arylsulfatase A activity. 135 86


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