1
|
Okumiya T, Kroos MA, Vliet LV, Takeuchi H, Van der Ploeg AT, Reuser AJJ. Chemical chaperones improve transport and enhance stability of mutant alpha-glucosidases in glycogen storage disease type II. Mol Genet Metab 2007; 90:49-57. [PMID: 17095274 DOI: 10.1016/j.ymgme.2006.09.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 09/20/2006] [Accepted: 09/20/2006] [Indexed: 11/15/2022]
Abstract
Glycogen storage disease type II (GSDII; Pompe disease or acid maltase deficiency) is an autosomal recessive disorder caused by lysosomal acid alpha-glucosidase (AalphaGlu) deficiency and manifests predominantly as skeletal muscle weakness. Defects in post-translational modification and transport of mutant AalphaGlu species are frequently encountered and may potentially be corrected with chaperone-mediated therapy. In the present study, we have tested this hypothesis by using deoxynojirimycin and derivatives as chemical chaperones to correct the AalphaGlu deficiency in cultured fibroblasts from patients with GSDII. Four mutant phenotypes were chosen: Y455F/Y455F, P545L/P545L, 525del/R600C and D645E/R854X. In case of Y455F/Y455F and P545L/P545L, N-(n-butyl)deoxynojirimycin (NB-DNJ) restored the transport, maturation and activity of AalphaGlu in a dose dependent manner, while it had no effect on the reference enzyme beta-hexosaminidase. NB-DNJ promoted export from the endoplasmic reticulum (ER) to the lysosomes and stabilized the activity of mutant AalphaGlu species, Y455F and P545L, inside the lysosomes. In long-term culture, the AalphaGlu activity in the fibroblasts from the patients with mutant phenotypes, Y455F/Y455F and P545L/P545L, increased up to 14.0- and 7.9-fold, respectively, in the presence of 10mumol/L NB-DNJ. However, the effect of NB-DNJ on Y455F/Y455F subsided quickly after removal of the compound. We conclude that NB-DNJ acts in low concentration as chemical chaperone for certain mutant forms of AalphaGlu that are trapped in the ER, poorly transported or labile in the lysosomal environment. Chemical chaperone therapy could create new perspectives for therapeutic intervention in GSDII.
Collapse
Affiliation(s)
- Toshika Okumiya
- Department of Clinical Genetics, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
2
|
Du H, Levine M, Ganesa C, Witte DP, Cole ES, Grabowski GA. The role of mannosylated enzyme and the mannose receptor in enzyme replacement therapy. Am J Hum Genet 2005; 77:1061-74. [PMID: 16380916 PMCID: PMC1285163 DOI: 10.1086/498652] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 10/03/2005] [Indexed: 11/03/2022] Open
Abstract
Lysosomal acid lipase (LAL) is the critical enzyme for the hydrolysis of triglycerides (TGs) and cholesteryl esters (CEs) in lysosomes. LAL defects cause Wolman disease (WD) and CE storage disease (CESD). An LAL null (lal-/-) mouse model closely mimics human WD/CESD, with hepatocellular, Kupffer cell and other macrophage, and adrenal cortical storage of CEs and TGs. The effect on the cellular targeting of high-mannose and complex oligosaccharide-type oligosaccharide chains was tested with human LAL expressed in Pichia pastoris (phLAL) and CHO cells (chLAL), respectively. Only chLAL was internalized by cultured fibroblasts, whereas both chLAL and phLAL were taken up by macrophage mannose receptor (MMR)-positive J774E cells. After intraperitoneal injection into lal-/- mice, phLAL and chLAL distributed to macrophages and macrophage-derived cells of various organs. chLAL was also detected in hepatocytes. Ten injections of either enzyme over 30 d into 2- and 2.5-mo-old lal-/- mice produced normalization of hepatic color, decreased liver weight (50%-58%), and diminished hepatic cholesterol and TG storage. Lipid accumulations in macrophages were diminished with either enzyme. Only chLAL cleared lipids in hepatocytes. Mice double homozygous for the LAL and MMR deficiences (lal-/-;MMR-/-) showed phLAL uptake into Kupffer cells and hepatocytes, reversal of macrophage histopathology and lipid storage in all tissues, and clearance of hepatocytes. These results implicate MMR-independent and mannose 6-phosphate receptor-independent pathways in phLAL uptake and delivery to lysosomes in vivo. In addition, these studies show specific cellular targeting and physiologic effects of differentially oligosaccharide-modified human LALs mediated by MMR and that lysosomal targeting of mannose-terminated glycoproteins occurs and storage can be eliminated effectively without MMR.
Collapse
Affiliation(s)
- Hong Du
- Division and Program in Human Genetics and Division of Pathology, Cincinnati Children’s Hospital Research Foundation, Cincinnati; and Genzyme, Cambridge, MA
| | - Mark Levine
- Division and Program in Human Genetics and Division of Pathology, Cincinnati Children’s Hospital Research Foundation, Cincinnati; and Genzyme, Cambridge, MA
| | - Chandrashekar Ganesa
- Division and Program in Human Genetics and Division of Pathology, Cincinnati Children’s Hospital Research Foundation, Cincinnati; and Genzyme, Cambridge, MA
| | - David P. Witte
- Division and Program in Human Genetics and Division of Pathology, Cincinnati Children’s Hospital Research Foundation, Cincinnati; and Genzyme, Cambridge, MA
| | - Edward S. Cole
- Division and Program in Human Genetics and Division of Pathology, Cincinnati Children’s Hospital Research Foundation, Cincinnati; and Genzyme, Cambridge, MA
| | - Gregory A. Grabowski
- Division and Program in Human Genetics and Division of Pathology, Cincinnati Children’s Hospital Research Foundation, Cincinnati; and Genzyme, Cambridge, MA
| |
Collapse
|
3
|
Ishida-Yamamoto A, Simon M, Kishibe M, Miyauchi Y, Takahashi H, Yoshida S, O'Brien TJ, Serre G, Iizuka H. Epidermal lamellar granules transport different cargoes as distinct aggregates. J Invest Dermatol 2004; 122:1137-44. [PMID: 15140216 DOI: 10.1111/j.0022-202x.2004.22515.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Lamellar granules (LG) of the epidermis appear as discrete round or oblong shaped granules in classical transmission electron micrographs, but a recent cryo-transmission electron microscopy study has claimed that LG are in fact branched tubular structures. LG contain various cargoes including lipids, hydrolytic enzymes, and several other proteins. It is not known whether there are any differences in the timing of expression among them and whether they are sorted into the granules individually or collectively. In order to address these questions, we studied the expression of glucosylceramides (GlcCer), cathepsin D (CatD), corneodesmosin (Cdsn), kallikrein (KLK)7, and KLK8 in normal human epidermis using confocal laser scanning microscopy and immunoelectron microscopy. The results were consistent with the model that LG are parts of a branched tubular structure. In this structure, all the components were shown to be distributed as separate aggregates. In the trans-Golgi network (TGN), bulbous protrusions containing GlcCer, Cdsn, KLK7 and KLK8, and small CatD-positive vesicles were observed. The molecules were shown to be delivered to the apical region of granular keratinocytes. This study provides strong evidence for the sequential synthesis and independent trafficking of various LG cargoes, including for the first time CatD and KLK8, from TGN.
Collapse
|
4
|
de Crom R, van Haperen R, Janssens R, Visser P, Willemsen R, Grosveld F, van der Kamp A. Gp96/GRP94 is a putative high density lipoprotein-binding protein in liver. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1437:378-92. [PMID: 10101271 DOI: 10.1016/s1388-1981(99)00017-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have previously shown that three high density lipoproteins (HDL)-binding proteins in liver, of 90, 110 and 180 kDa, are structurally related. In this study, these proteins are identified as gp96/GRP94. This protein is known to occur as a homodimer and has a dual subcellular localization: it is both an endoplasmic reticulum resident protein, where it is supposed to act as a chaperonin, and a plasma membrane protein, whose significance is unknown. In ultrastructural studies the plasma membrane localization of the homodimeric form was verified. The 90-kDa protein was abundantly present at the membranes of the endosomal/lysosomal vesicles as well as at the apical hepatocyte membranes, comprising the bile canaliculi. The monomeric protein is scarcely present at the basolateral membrane of the hepatocytes, but could be demonstrated in coated pits, suggesting involvement in receptor-mediated endocytosis. Labeling of the endoplasmic reticulum was virtually absent. Gp96/GRP94 was transiently expressed in COS-1 cells. However, the expressed protein was exclusively localized in the endoplasmic reticulum. Transfection with constructs in which the C-terminal KDEL sequence had been deleted, resulted in plasma membrane localized expression of protein, but only in an extremely low percentage of cells. In order to evaluate the HDL-binding capacities of this protein, stably transfected cells were generated, using several cell types. It appeared to be difficult to obtain a prolonged high level expression of gp96. In these cases, however, a marked increase of HDL-binding activity compared with the control cells could be observed.
Collapse
Affiliation(s)
- R de Crom
- The Medical Genetics Center, Department of Cell Biology and Genetics, Erasmus University Rotterdam, Dr. Molenwaterplein 50, P.O. Box 1738, 3000 DR, Rotterdam, The
| | | | | | | | | | | | | |
Collapse
|
5
|
Detection and Isolation of Gene-Corrected Cells in Gaucher Disease Via a Fluorescence-Activated Cell Sorter Assay for Lysosomal Glucocerebrosidase Activity. Blood 1997. [DOI: 10.1182/blood.v89.9.3412] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractGaucher disease type 1 results from the accumulation of glucocerebroside in macrophages of the reticuloendothelial system, as a consequence of a deficiency in glucocerebrosidase (GC) activity. Recent improvements in the methodologies for introducing foreign genes into bone marrow stem cells have prompted several groups to test the efficacy of gene transfer therapy as a curative treatment for Gaucher disease. Limitations of this approach include the potential for insufficient engraftment of gene-corrected cells and incomplete transduction of hematopoietic stem cells using retroviral gene transfer. Overcoming these obstacles may be critical in the case of treatment for Gaucher disease type 1, because GC transduced cells have not been shown to have a growth advantage over noncorrected cells. Here, we describe the development and application of a novel, fluorescence-activated cell sorter based assay that directly quantitates GC activity at the single cell level. In a test of this application, fibroblasts from a Gaucher patient were transduced, and high expressing cells sorted based on GC activity. Reanalysis of cultured sorted fibroblasts reveals that these cells maintain high levels of enzymatic activity, compared with the heterogeneous population from which they were sorted. The assay is sufficiently sensitive to distinguish GC activity found in Gaucher patient monocytes from that in normal controls. Furthermore, preliminary results indicate that increased GC activity can be detected in transduced, CD34+ enriched peripheral blood mononuclear cells isolated from a Gaucher patient. This method should be a useful addition to current gene therapy protocols as a means to quantitatively assess gene correction of relevant cell populations and potentially purify transduced cells for transplantation.
Collapse
|
6
|
Fuller M, Van der Ploeg A, Reuser AJ, Anson DS, Hopwood JJ. Isolation and characterisation of a recombinant, precursor form of lysosomal acid alpha-glucosidase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 234:903-9. [PMID: 8575451 DOI: 10.1111/j.1432-1033.1995.903_a.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glycogenosis type II (GSD II, Pompe disease) is an autosomal recessive lysosomal storage disease that results from a deficiency of acid alpha-glucosidase (GAA). Patients with this disorder are unable to break down lysosomal glycogen, which consequently accumulates in the lysosome. To evaluate enzyme replacement therapy for GSD II patients, we have expressed human GAA cDNA in Chinese hamster ovary-K1 cells utilising a vector that places the cDNA under the transcriptional control of the human polypeptide chain elongation factor 1 alpha gene promoter. A clonal cell line that secreted precursor recombinant GAA at approximately 18 mg.l-1.day-1 was identified. The precursor recombinant GAA was purified to homogeneity, had a molecular mass of 110 kDa as measured by SDS/PAGE, and was shown to have pH optima and kinetic parameters similar to those of GAA purified from human tissues. The partial N-terminal amino acid sequence of recombinant GAA conformed to that derived from the nucleotide sequence of the cloned cDNA. The recombinant enzyme was taken up by cultured fibroblasts and skeletal muscle cells from GSD II patients, and was shown to correct the storage phenotype. Endocytosed GAA was localised to the lysosome and showed evidence of intracellular processing to a more mature form. Activity levels increased up to twice the normal value and uptake was prevented if cells were cultured in the presence of mannose 6-phosphate.
Collapse
Affiliation(s)
- M Fuller
- Department of Chemical Pathology, Women's and Children's Hospital, North Adelaide, Australia
| | | | | | | | | |
Collapse
|
7
|
Verheij C, Bakker CE, de Graaff E, Keulemans J, Willemsen R, Verkerk AJ, Galjaard H, Reuser AJ, Hoogeveen AT, Oostra BA. Characterization and localization of the FMR-1 gene product associated with fragile X syndrome. Nature 1993; 363:722-4. [PMID: 8515814 DOI: 10.1038/363722a0] [Citation(s) in RCA: 239] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The fragile X syndrome is the most frequent form of inherited mental retardation after Down's syndrome, having an incidence of one in 1,250 males. The fragile X syndrome results from amplification of the CGG repeat found in the FMR-1 gene. This CGG repeat shows length variation in normal individuals and is increased significantly in both carriers and patients; it is located 250 base pairs distal to a CpG island which is hypermethylated in fragile X patients. The methylation probably results in downregulation of FMR-1 gene expression. No information can be deduced about the function of the FMR-1 protein from its predicted sequence. Here we investigate the nature and function of the protein encoded by the FMR-1 gene using polyclonal antibodies raised against the predicted amino-acid sequences. Four different protein products, possibly resulting from alternative splicing, have been identified by immunoblotting in lymphoblastoid cell lines of healthy individuals. All these proteins were missing in cell lines from patients not expressing FMR-1 messenger RNA. The intracellular localization of the FMR-1 gene products was investigated by transient expression in COS-1 cells and found to be cytoplasmic. Localization was also predominantly cytoplasmic in the epithelium of the oesophagus, but in some cells was obviously nuclear.
Collapse
Affiliation(s)
- C Verheij
- MGC Department of Clinical Genetics, Erasmus University, Rotterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Park H, Vettese MB, Fensom AH, Fisher KJ, Aronson NN. Characterization of three alleles causing aspartylglycosaminuria: two from a British family and one from an American patient. Biochem J 1993; 290 ( Pt 3):735-41. [PMID: 8457202 PMCID: PMC1132342 DOI: 10.1042/bj2900735] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Aspartylglycosaminuria (AGU) is a lysosomal storage disease principally occurring in Finland that results from mutations in the structural gene for glycosylasparaginase (AGU). This work characterizes the inheritance of two previously reported AGU mutations in a British patient [Ikonen, Aula, Grön, Tollersrud, Halila, Manninen, Syvänen and Peltonen (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 11222-11226]. Use of the PCR determined the glycosylasparaginase cDNA sequence from both parents of the British patient and his AGU-affected brother. The father of the British AGU-affected siblings was found to be a heterozygote carrier for a C-->T point mutation which causes an Ala-->Val amino-acid substitution, while the mother was heterozygous for a 7 bp deletion that results in premature translational termination. The brother of the previously studied patient was similarly shown to be a compound heterozygote. Expression in COS-1 cells revealed the paternal Ala-->Val amino-acid substitution destroyed glycosylasparaginase catalytic activity, prevented transport of the mutant protein to the lysosome, and prevented maturation of the enzyme precursor to its native subunit structure. The Ala-->Val mutation therefore affects glycosylasparaginase in a manner similar to the Finnish AGU Cys-->Ser substitution, further supporting a linkage of glycosylasparaginase catalytic activity to its lysosomal transport and subunit processing [Fisher and Aronson (1991) J. Biol. Chem. 266, 12105-12113]. In addition, a 5 bp deletion mutation from an American patient with AGU has been characterized. The deleted sequence occurs at the beginning of the glycosylasparaginase coding sequence, resulting in an extremely truncated polypeptide. The American 5 bp deletion and the British maternal 7 bp deletion possibly decrease mRNA stability.
Collapse
Affiliation(s)
- H Park
- Department of Molecular and Cell Biology, Althouse Laboratory, Pennsylvania State University, University Park 16802
| | | | | | | | | |
Collapse
|
9
|
Wisselaar H, Kroos M, Hermans M, van Beeumen J, Reuser A. Structural and functional changes of lysosomal acid alpha-glucosidase during intracellular transport and maturation. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53985-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
10
|
Nebes VL, Jones EW. N-linked glycosylation of proteinase B precursors of the yeast Saccharomyces cerevisiae is not required for proper targeting or processing of the enzyme. Yeast 1992; 8:353-9. [PMID: 1626428 DOI: 10.1002/yea.320080503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Proteinase B precursors are modified by an N-linked carbohydrate side chain at Asn 314. Glycosylation at this position is not required for proper localization, processing, or activation of the enzyme.
Collapse
Affiliation(s)
- V L Nebes
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
| | | |
Collapse
|
11
|
Hermans MM, de Graaff E, Kroos MA, Wisselaar HA, Oostra BA, Reuser AJ. Identification of a point mutation in the human lysosomal alpha-glucosidase gene causing infantile glycogenosis type II. Biochem Biophys Res Commun 1991; 179:919-26. [PMID: 1898413 DOI: 10.1016/0006-291x(91)91906-s] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two patients in a consanguineous Indian family with infantile glycogenosis type II were found to have a G to A transition in exon 11 of the human lysosomal alpha-glucosidase gene. Both patients were homozygous and both parents were heterozygous for the mutant allele. The mutation causes a Glu to Lys substitution at amino acid position 521, just three amino acids downstream from the catalytic site at Asp-518. The mutation was introduced in wild type lysosomal alpha-glucosidase cDNA and the mutant construct was expressed in vitro and in vivo. The Glu to Lys substitution is proven to account for the abnormal physical properties of the patients lysosomal alpha-glucosidase precursor and to prevent the formation of catalytically active enzyme. In homozygous form it leads to the severe infantile phenotype of glycogenosis type II.
Collapse
Affiliation(s)
- M M Hermans
- Department of Cell Biology & Genetics, Erasmus University, Rotterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
12
|
Fisher KJ, Aronson NN. Deletion of exon 8 causes glycosylasparaginase deficiency in an African American aspartylglucosaminuria (AGU) patient. FEBS Lett 1991; 288:173-8. [PMID: 1879549 DOI: 10.1016/0014-5793(91)81028-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have indentified a GT-to-TT transversion at the splice donor site of intron 8 in the glycosylasparaginase gene from an African American aspartylglucosaminuria (AGU) patient. This mutation causes abnormal splicing of glycosylasparaginase pre-mRNA by joining exon 7 to 9 and excluding 134 bp exon 8. The effect of the mutation is compounded by a frame shift that occurs after the deletion site resulting in premature translational termination. The truncated AGU protein was neither catalytically active nor processed into mature alpha and beta subunits. Both this and a previously characterized Finnish AGU mutation appear to affect folding of the single-chain precursor of glycosylasparaginase and thereby prevent transport of the enzyme to lysosomes.
Collapse
Affiliation(s)
- K J Fisher
- Department of Molecular and Cell Biology, Althouse Lab, Pennsylvania State University, University Park 16802
| | | |
Collapse
|
13
|
Galjart N, Morreau H, Willemsen R, Gillemans N, Bonten E, d'Azzo A. Human lysosomal protective protein has cathepsin A-like activity distinct from its protective function. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98751-x] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
14
|
Hoefsloot LH, Willemsen R, Kroos MA, Hoogeveen-Westerveld M, Hermans MM, Van der Ploeg AT, Oostra BA, Reuser AJ. Expression and routeing of human lysosomal alpha-glucosidase in transiently transfected mammalian cells. Biochem J 1990; 272:485-92. [PMID: 2268275 PMCID: PMC1149726 DOI: 10.1042/bj2720485] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Previously isolated lysosomal alpha-glucosidase cDNA clones were ligated to full-length constructs for expression in vitro and in mammalian cells. One of these constructs (pSHAG1) did not code for functional enzyme, due to an arginine residue instead of a tryptophan residue at amino acid position 402. The mutation does not affect the rate of enzyme synthesis, but interferes with post-translational modification and intracellular transport of the acid alpha-glucosidase precursor. Using immunocytochemistry it is demonstrated that the mutant precursor traverses the endoplasmic reticulum and the Golgi complex, but does not reach the lysosomes. Pulse-chase experiments suggest premature degradation. The Trp-402-containing enzyme (encoded by construct pSHAG2) is processed properly, and has catalytic activity. A fraction of the enzyme is localized at the plasma membrane. It is hypothesized that membrane association of the acid alpha-glucosidase precursor, as demonstrated by Triton X-114 phase separation, is responsible for transport to this location. Transiently expressed acid alpha-glucosidase also enters the secretory pathway, since a catalytically active precursor is found in the culture medium. This precursor has the appropriate characteristics for use in enzyme replacement therapy. Efficient uptake via the mannose 6-phosphate receptor results in degradation of lysosomal glycogen in cultured fibroblasts and muscle cells from patients with glycogenosis type II.
Collapse
Affiliation(s)
- L H Hoefsloot
- MGC-Department of Cell Biology and Genetics, Erasmus University, Rotterdam, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Persson H, Corneliuson O. Separation and identification of 2',3'-cyclic nucleotide 3'-phosphodiesterase on isoelectric focusing gels. Anal Biochem 1990; 186:90-4. [PMID: 2162637 DOI: 10.1016/0003-2697(90)90578-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A method is presented for the separation and detection of the myelin marker enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase on isoelectric focusing gels and by immunoblotting. The gel staining procedure is a modification of a method used to demonstrate enzyme activity on blots after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional polyacrylamide gel electrophoresis. The results show that immunologically active 2',3'-cyclic nucleotide 3'-phosphodiesterase can be separated under equilibrium conditions on isoelectric focusing gels with an expanded alkaline pH range after solubilization in a mixture of nonionic/zwitterionic detergents and urea. Enzymatically active 2',3'-cyclic nucleotide 3'-phosphodiesterase focused as two closely spaced bands at pIapp 8.1 and 8.8, respectively, while 2',3'-cyclic nucleotide 3'-phosphodiesterase immunoreactivity was detected as four distinct bands at pIapp 4.2, 7.4, 8.8, and 9.3 and a diffuse band at pIapp 7.9-8.2. By two-dimensional separation these five bands showed molecular weights of about 43-47 kDa, i.e., corresponding to reported values for immunologically active 2',3'-cyclic nucleotide 3'-phosphodiesterase. Since enzyme activity is associated with only two of the bands, nonspecific and artifactual banding due to, e.g., detergent micelle formation, is unlikely.
Collapse
Affiliation(s)
- H Persson
- Department of Anatomy, Gothenburg University, Göteborg, Sweden
| | | |
Collapse
|
16
|
Morreau H, Galjart N, Gillemans N, Willemsen R, van der Horst G, d'Azzo A. Alternative splicing of β-galactosidase mRNA generates the classic lysosomal enzyme and a β-galactosidase-related protein. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)47114-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
17
|
Correll PH, Fink JK, Brady RO, Perry LK, Karlsson S. Production of human glucocerebrosidase in mice after retroviral gene transfer into multipotential hematopoietic progenitor cells. Proc Natl Acad Sci U S A 1989; 86:8912-6. [PMID: 2573069 PMCID: PMC298400 DOI: 10.1073/pnas.86.22.8912] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The human glucocerebrosidase (GC) gene has been transferred efficiently into spleen colony-forming unit (CFU-S) multipotential hematopoietic progenitor cells, and production of human GC RNA and protein has been achieved in transduced CFU-S colonies. High-titer retroviral vectors containing the human GC cDNA were constructed. Mouse bone marrow cells were stimulated with hematopoietic growth factors, infected by coculture with producer cells, and injected into lethally irradiated animals. Four vectors were compared with respect to gene-transfer efficiency into CFU-S progenitors. One vector (G vector) required high concentrations of interleukins 3 and 6 during stimulation and coculture for efficient transduction of CFU-S progenitors. The remaining three vectors (NTG, GTN, and GI vectors) transduced these progenitors at infection frequencies approaching 100% using low concentrations of hematopoietic growth factors to stimulate cell division prior to and during the infection. Vectors using the viral long terminal repeat enhancer/promoter to drive the human GC cDNA produced high levels of human GC RNA in the progeny of CFU-S progenitors after gene transfer. When an internal herpes simplex thymidine kinase promoter assisted by a mutant polyoma enhancer was used to drive the human GC cDNA (NTG vector), little or no human GC RNA was detected in transduced CFU-S colonies. All three vectors producing human GC RNA in CFU-S colonies can generate human GC as detected by immunochemical analysis of CFU-S colonies. NTG vector-infected bone marrow cells were transplanted into W/Wv recipients to generate long-term reconstituted mice. The capacity of the viral long terminal repeat and the internal thymidine kinase promoter to direct synthesis of RNA in transduced bone marrow and spleen cells 5 months after bone marrow transplantation reflected the performance of these promoters in NTG-transduced CFU-S colonies.
Collapse
Affiliation(s)
- P H Correll
- Molecular and Medical Genetics Section, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892
| | | | | | | | | |
Collapse
|
18
|
van der Ploeg AT, Bolhuis PA, Wolterman RA, Visser JW, Loonen MC, Busch HF, Reuser AJ. Prospect for enzyme therapy in glycogenosis II variants: a study on cultured muscle cells. J Neurol 1988; 235:392-6. [PMID: 3065462 DOI: 10.1007/bf00314479] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Impairment of skeletal muscle function is the common feature of distinct clinical forms of glycogenosis type II. In the present study, muscle cultures from different patients were used to investigate the cause of clinical heterogeneity and the feasibility of enzyme replacement therapy. The activity of acid alpha-glucosidase appears to be the primary factor in determining the extent of lysosomal glycogen storage in muscle, and thereby the clinical severity of the disease. Neutral alpha-glucosidases do not seem influential. Correction of the enzymatic defect was achieved in skeletal muscle cultures from patients by administration of a "high-uptake" form of acid alpha-glucosidase, purified from human urine. The enzyme reaches the lysosomes, including the glycogen storage vacuoles, and the lysosomal glycogen content is reduced to control level. In normal muscle cells 20% of the total cellular glycogen pool is segregated in lysosomal compartments. This percentage is higher than in fibroblasts, which may partly explain why muscles are more prone to store glycogen. The relevance of this study for enzyme therapy is discussed.
Collapse
Affiliation(s)
- A T van der Ploeg
- Department of Cell Biology, Erasmus University, Rotterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
19
|
Olsen I, Abraham D, Shelton I, Bou-Gharios G, Muir H, Winchester B. Cell contact induces the synthesis of a lysosomal enzyme precursor in lymphocytes and its direct transfer to fibroblasts. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 968:312-22. [PMID: 3278745 DOI: 10.1016/0167-4889(88)90022-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The activity of a lysosomal enzyme, alpha-D-mannosidase (EC 3.2.1.24), increased markedly in normal lymphocytes when they were cultured together with fibroblasts from a patient with an inherited deficiency of this enzyme. Cell-to-cell contact was obligatory for this increase in activity, which also required new protein synthesis. The enzyme induced in the co-cultured lymphocytes was a high molecular weight form of alpha-D-mannosidase that was not detected in lymphocytes cultured alone, which had only the low molecular weight mature enzyme. It was this precursor form alone that was directly transferred to the mannosidosis fibroblasts, where it was present initially in organelles of low density. When the culture period was extended the lymphocyte precursor enzyme was transported to the heavy lysosomes in the recipient cells, and correctly processed to the functionally effective mature enzyme.
Collapse
Affiliation(s)
- I Olsen
- Kennedy Institute of Rheumatology, London, U.K
| | | | | | | | | | | |
Collapse
|
20
|
Abraham D, Muir H, Winchester B, Olsen I. Lymphocytes transfer only the lysosomal form of alpha-D-mannosidase during cell-to-cell contact. Exp Cell Res 1988; 175:158-68. [PMID: 3345799 DOI: 10.1016/0014-4827(88)90263-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have examined the changes in the activities of the different types of alpha-D-mannosidase when fibroblasts from patients deficient in the lysosomal form of the enzyme are cultured together with normal lymphocytes. Our results show that whereas the mannosidosis cells acquired high levels of this enzyme, the activities of both the Golgi and the endoplasmic reticulum forms of alpha-D-mannosidase remained the same as in the fibroblasts cultured alone in the absence of lymphocytes. The increase in the activity of the lysosomal enzyme in the cocultured fibroblasts was not affected by the presence of mannose 6-phosphate or alpha-methyl mannoside, inhibitors of receptor- and lectin-mediated uptake of lysosomal enzymes, respectively, but it did require cell-to-cell contact. Ion-exchange HPLC and electrophoresis in polyacrylamide gradient gels showed that the acquired enzyme had the same elution profile and molecular size as the lysosomal form of the enzyme present in the lymphocytes. Immunoprecipitation studies using antibody specific for the lymphocyte type of lysosomal alpha-D-mannosidase confirmed that the increased activity in the cocultured mannosidosis cells resulted from the acquisition of the lymphocyte enzyme. Cytochemical examination revealed, however, that the transferred lymphocyte enzyme was localized in cytoplasmic organelles in the peripheral regions of the recipient fibroblasts. These results show that lymphocytes transfer only the lysosomal form of alpha-D-mannosidase during cell-to-cell contact with mannosidosis cells.
Collapse
Affiliation(s)
- D Abraham
- Kennedy Institute of Rheumatology, Bute Gardens, London, United Kingdom
| | | | | | | |
Collapse
|
21
|
Willemsen R, Kroos M, Hoogeveen AT, van Dongen JM, Parenti G, van der Loos CM, Reuser AJ. Ultrastructural localization of steroid sulphatase in cultured human fibroblasts by immunocytochemistry: a comparative study with lysosomal enzymes and the mannose 6-phosphate receptor. THE HISTOCHEMICAL JOURNAL 1988; 20:41-51. [PMID: 2967269 DOI: 10.1007/bf01745968] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Immunocytochemistry was used to study the subcellular localization of steroid sulphatase in cultured human fibroblasts. Ultra-thin cryosections were incubated with antibodies raised against steroid sulphatase purified from human placenta and immune complexes were visualized with gold probes as electron dense markers. Steroid sulphatase was found in rough endoplasmic reticulum, Golgi cisternae and in the trans-Golgi reticulum, where it co-distributes with lysosomal enzymes and the mannose 6-phosphate receptor. The enzyme was not detected in lysosomes. Steroid sulphatase was also found at the plasma membrane and in the endocytic pathway (i.e. coated pits, endosomes and multivesicular endosomes). These may be the sites where sulphated oestrogen precursors are hydrolysed. Also here, it co-localizes with lysosomal enzymes and the mannose 6-phosphate receptor. It is concluded that microsomal steroid sulphatase and lysosomal enzymes share several cellular compartments.
Collapse
Affiliation(s)
- R Willemsen
- Department of Cell Biology and Genetics, Erasmus University, Rotterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
22
|
Bou-Gharios G, Moss J, Olsen I, Partridge T. Ultrastructural localization of a lysosomal enzyme in resin-embedded lymphocytes. HISTOCHEMISTRY 1988; 89:69-74. [PMID: 3284854 DOI: 10.1007/bf00496587] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The intracellular distribution of lysosomal enzymes in lymphocytes has previously been only poorly defined, mainly by cytochemical procedures of low resolution. In the present study we have used a post-embedding immunogold technique to identify the precise ultrastructural localization of a lysosomal enzyme, beta-glucuronidase, in activated lymphocytes embedded in Lowicryl K4M resin. We show that this enzyme is present in the rough endoplasmic reticulum, in the Golgi complex, and in vesicular organelles which probably include lysosomes.
Collapse
Affiliation(s)
- G Bou-Gharios
- Department of Histopathology, Charing Cross and Westminster Medical School, London, UK
| | | | | | | |
Collapse
|
23
|
Storrie B. Assembly of lysosomes: perspectives from comparative molecular cell biology. INTERNATIONAL REVIEW OF CYTOLOGY 1988; 111:53-105. [PMID: 3074962 DOI: 10.1016/s0074-7696(08)61731-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- B Storrie
- Department of Biochemistry and Nutrition, Virginia Polytechnic Institute and State University, Blacksburg 24061
| |
Collapse
|
24
|
Yokota S, Nishimura Y, Kato K. Localization of cathepsin L in rat kidney revealed by immunoenzyme and immunogold techniques. HISTOCHEMISTRY 1988; 90:277-83. [PMID: 3068216 DOI: 10.1007/bf00495971] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Localization of cathepsin L in rat kidney was investigated by immunocytochemical techniques. Kidneys were fixed by perfusion and embedded in Epon or Lowicryl K4M without postosmication. For light microscopy (LM), semi-thin sections of the Epon-embedded material were stained by the immunoenzyme technique after removal of epoxy resin. For electron microscopy (EM), ultra-thin sections of Lowicryl K4M-embedded material were stained by the protein A-gold technique. By LM, reaction deposits for cathepsin L were present in the cytoplasmic granules of proximal tubule cells, but little or no reaction product was noted in distal tubule, collecting tubule, and most of urinary tubules in the medulla. By EM, heavy gold label for cathepsin L was confined exclusively to lysosomes of the proximal tubule cells, but little or no label to those of the other segments. In immunocytochemical control sections, no reaction was observed. These results indicate that a main container of cathepsin L is lysosomes of the proximal tubule and suggest that the enzyme plays a role in the degradation of endocytosed proteins.
Collapse
Affiliation(s)
- S Yokota
- Department of Anatomy, Yamanashi Medical School, Japan
| | | | | |
Collapse
|
25
|
Yokota S, Kato K. Immunocytochemical localization of cathepsins B and H in rat liver. HISTOCHEMISTRY 1987; 88:97-103. [PMID: 3325480 DOI: 10.1007/bf00490174] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Light and electron microscopic localization of cathepsins B and H in rat liver was investigated by immunoenzyme and protein A-gold techniques. For light microscopy (LM), semi-thin sections of the Epon-embedded material were stained by the immunoenzyme technique after removal of epoxy resin. For electron microscopy (EM), ultra-thin sections of the Lowicryl K4M-embedded material were stained by the protein A-gold technique. By LM, reaction deposits for cathepsins B and H were present in the cytoplasmic granules of parenchymal cells and endothelial cells, and Kupffer cells. The sinus-lining cells and the parenchymal cells showed the similar staining intensity. By EM, gold particles were present exclusively in lysosomes of all the cell types cited above. The same results were obtained from quantitative analysis. In addition, Golgi complexes themselves were mostly negative but some small vesicles on the trans side of them were labeled for these proteinases. The results indicate that cathepsins B and H are present in the lysosomes of rat liver and that these enzymes seem to be transported by small vesicles from endoplasmic reticulum to lysosomes via tubuloreticular network of the trans Golgi region.
Collapse
Affiliation(s)
- S Yokota
- Department of Anatomy, Yamanashi Medical School, Japan
| | | |
Collapse
|
26
|
Willemsen R, van Dongen JM, Ginns EI, Sips HJ, Schram AW, Tager JM, Barranger JA, Reuser AJ. Ultrastructural localization of glucocerebrosidase in cultured Gaucher's disease fibroblasts by immunocytochemistry. J Neurol 1987; 234:44-51. [PMID: 3819786 DOI: 10.1007/bf00314009] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The subcellular localization of glucocerebrosidase was studied in cultured skin fibroblasts from eight patients with Gaucher's disease. The enzyme, in situ, was visualized under the electron microscope by incubating ultrathin frozen sections of fibroblasts with antibodies against glucocerebrosidase, followed by a second incubation with goat anti- (rabbit IgG) coupled to colloidal gold. In control cells, most of the gold label was found in lysosomes, associated with the membrane. Labelling of the rough endoplasmic reticulum (RER) and Golgi complex was also observed. In fibroblasts from three Gaucher's disease patients without neurological symptoms (type 1 disease), a near normal amount of cross-reactive material (CRM) was detected in lysosomes, but in a fourth such patient, the lysosomal CRM was reduced. Little lysosomal glucocerebrosidase was detected in cells from patients with the acute neuronopathic form (type 2) or the subacute neuronopathic form (type 3) of Gaucher's disease. CRM in lysosomes correlates with amount of mature, 59 kDA glucocerebrosidase which is undetectable in type 2 and type 3 Gaucher's disease cell lines. These findings demonstrate that different mutations in the gene for glucocerebrosidase result in mutant proteins that have different intracellular localizations. They also suggest that there is a relationship between the amount of cross-reactive material in the lysosomes and the phenotypic expression of the disease.
Collapse
|
27
|
|
28
|
Sips HJ, Reuser AJ, van der Veer E. Synthesis and intracellular localization of chick acid alpha-glucosidase in chick erythrocyte-human fibroblast heterokaryons. A model system for the study of lysosomal enzyme synthesis. Exp Cell Res 1986; 162:555-61. [PMID: 3510883 DOI: 10.1016/0014-4827(86)90360-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The synthesis and localization of chick acid alpha-glucosidase has been studied in chick erythrocyte-human fibroblast heterokaryons. Monospecific antibodies raised against purified chick liver acid alpha-glucosidase were used. It was found that the acid alpha-glucosidase in the heterokaryons is of chick origin, and is localized in the same lysosomes as the human lysosomal enzymes. It is concluded that chick erythrocyte-human fibroblast heterokaryons provide a useful model system for the study of lysosomal enzyme synthesis and routing.
Collapse
|
29
|
Yokota S, Tsuji H, Kato K. Immunocytochemical localization of cathepsin H in rat kidney. Light and electron microscopic study. HISTOCHEMISTRY 1986; 85:223-30. [PMID: 3091544 DOI: 10.1007/bf00494808] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Light and electron microscopic localization of cathepsin H in rat kidney was studied using post-embedding immunocytochemical techniques. For light microscopy, Epon sections of the kidney were stained by immunoenzyme method after removal of Epon and for electron microscopy, ultrathin sections of the Lowicryl K4M-embedded material were labeled by protein A-gold (pAg) technique. By light microscopy, fine granular staining was found in throughout the nephron, but the staining intensity considerably varied. The strongest staining was noted in the S1 segment of the proximal tubules followed by the S2 and S3 segments and the medullary collecting tubules. The glomeruli, the distal tubules, and the cortical collecting tubules were weakly stained. By electron microscopy, a gold label was found exclusively in lysosomes, which showed various sizes and labeling intensity. The results were quite consistent with the light microscopic results. The labeling intensity tended to increase as the matrix of lysosomes was condensed. Quantitative analysis of the labeling density of lysosomes demonstrated that the highest labeling density is found in the S1 segment of the proximal tubules and the labeling density of other renal segments is significantly low levels. The results indicate that a main site for cathepsin H in rat kidney is the S1 segment of the proximal tubules.
Collapse
|
30
|
Galjaard H. The role of cytochemistry in human genetic research. HISTOCHEMISTRY 1986; 84:301-7. [PMID: 3087916 DOI: 10.1007/bf00482954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The role of cytochemistry in human genetics is reviewed. In basic research, autoradiography and cytochemical staining procedures for DNA, RNA, proteins and other cell constituents have contributed to the understanding of the way DNA is localized, duplicated and translated. The development of new "banding techniques" for the identification of human chromosomes and parts of these together with somatic cell hybridization procedures have significantly contributed to the mapping of the human genome. Cytochemical methods have also been of great help in the elucidation of the responsible molecular defects in Mendelian disorders based on a single gene mutation. The combination of immunological methods and electron-microscopical cytochemistry now enables different posttranslational processing defects to be related to various subcellular compartments. Cytochemistry is also likely to be of importance for the direct demonstration of gene mutations using recombinant DNA technology. Examples are given of contributions of cytochemical methods to the early diagnosis and prevention of congenital disorders. The main examples are the early diagnosis of patients with a chromosomal aberration and of carriers with a balanced translocation. Early genetic counseling of couples at risk forms the basis for prevention of subsequent affected children. Cytochemistry also contributes to the early detection of heterozygotes of X-linked mutations. Finally, autoradiography and ultramicrochemical procedures have been of great help in improving the prenatal diagnosis of genetic metabolic diseases.
Collapse
|
31
|
Geuze HJ, Slot JW, Strous GJ, Hasilik A, von Figura K. Possible pathways for lysosomal enzyme delivery. J Cell Biol 1985; 101:2253-62. [PMID: 2933416 PMCID: PMC2114005 DOI: 10.1083/jcb.101.6.2253] [Citation(s) in RCA: 216] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Immunogold double-labeling and ultrathin cryosections were used to compare the subcellular distribution of albumin, mannose 6-phosphate receptor (MPR), galactosyltransferase, and the lysosomal enzymes cathepsin D, beta-hexosaminidase, and alpha-glucosidase in Hep G2 cells. MPR and lysosomal enzymes were found throughout the stack of Golgi cisternae and in a trans-Golgi reticulum (TGR) of smooth-surfaced tubules with coated buds and vesicles. The trans-Golgi orientation of TGR was ascertained by the co-localization with galactosyltransferase. MPR was particularly abundant in TGR and CURL, the compartment of uncoupling receptors and ligands. Both TGR and CURL also contained lysosomal enzymes, but endogenous albumin was detected in TGR only. The coated buds on TGR tubules contained MPR, lysosomal enzymes, as well as albumin. MPR and lysosomal enzymes were also found in coated pits of the plasma membrane. CURL tubules seemed to give rise to smooth vesicles, often of the multivesicular body type. In CURL, the enzymes were found in the lumina of the smooth vesicles while MPR prevailed in the tubules. These observations suggest a role of CURL in transport of lysosomal enzymes to lysosomes. When the cells were treated with the lysosomotropic amine primaquine, binding of anti-MPR to the cells in culture was reduced by half. Immunocytochemistry showed that MPR accumulated in TGR, especially in coated buds. Since these buds contain endogenous albumin and lysosomal enzymes also, these data suggest that coated vesicles originating from TGR provide for a secretory route in Hep G2 cells and that this pathway is followed by the MPR system as well.
Collapse
|
32
|
Erickson AH, Ginns EI, Barranger JA. Biosynthesis of the lysosomal enzyme glucocerebrosidase. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)38720-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
33
|
Sips HJ, De Jonge N, Van Dongen HM, Ramaekers FC, Reuser AJ. Monoclonal antibody to human lysosomal alpha-glucosidase in immunocytochemistry: unexpected reactivity with cytoskeletal structures. THE HISTOCHEMICAL JOURNAL 1985; 17:1043-52. [PMID: 3905722 DOI: 10.1007/bf01417953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A well-characterized monoclonal antibody against human lysosomal alpha-glucosidase has been used for the immunohistochemical localization of the enzyme in cultured human skin fibroblasts. Under conditions that are routinely used for the preparation of cells for immunocytochemistry, this monoclonal antibody does not react with acid alpha-glucosidase but in contrast with components of the cytoskeleton. Double-labelling experiments with the monoclonal antibody and rabbit anti-vimentin antiserum identified the cytoskeletal components as intermediate filaments. The implications of this observation for the use of monoclonal antibodies in immunocytochemistry in general are discussed.
Collapse
|