1
|
Todor H, Dulmage K, Gillum N, Bain JR, Muehlbauer MJ, Schmid AK. A transcription factor links growth rate and metabolism in the hypersaline adapted archaeon
H
alobacterium salinarum. Mol Microbiol 2014; 93:1172-82. [DOI: 10.1111/mmi.12726] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2014] [Indexed: 01/10/2023]
Affiliation(s)
- Horia Todor
- Department of Biology Duke University Durham NC 27708 USA
| | - Keely Dulmage
- Department of Biology Duke University Durham NC 27708 USA
- University Program in Genetics and Genomics Duke University Durham NC 27708 USA
| | | | - James R. Bain
- Sarah W. Stedman Nutrition and Metabolism Center Duke Molecular Physiology Institute Durham NC 27710 USA
| | - Michael J. Muehlbauer
- Sarah W. Stedman Nutrition and Metabolism Center Duke Molecular Physiology Institute Durham NC 27710 USA
| | - Amy K. Schmid
- Department of Biology Duke University Durham NC 27708 USA
- University Program in Genetics and Genomics Duke University Durham NC 27708 USA
- Center for Systems Biology Duke University Durham NC 27708 USA
| |
Collapse
|
2
|
Gründahl J, Guan Z, Rust S, Reunert J, Müller B, Du Chesne I, Zerres K, Rudnik-Schöneborn S, Ortiz-Brüchle N, Häusler M, Siedlecka J, Swiezewska E, Raetz C, Marquardt T. Life with too much polyprenol: polyprenol reductase deficiency. Mol Genet Metab 2012; 105:642-51. [PMID: 22304929 PMCID: PMC3428379 DOI: 10.1016/j.ymgme.2011.12.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 12/20/2011] [Accepted: 12/20/2011] [Indexed: 11/27/2022]
Abstract
Congenital disorders of glycosylation (CDG) are caused by a dysfunction of glycosylation, an essential step in the manufacturing process of glycoproteins. This paper focuses on a 6-year-old patient with a new type of CDG-I caused by a defect of the steroid 5α reductase type 3 gene (SRD5A3). The clinical features were psychomotor retardation, pathological nystagmus, slight muscular hypotonia and microcephaly. SRD5A3 was recently identified encoding the polyprenol reductase, an enzyme catalyzing the final step of the biosynthesis of dolichol, which is required for the assembly of the glycans needed for N-glycosylation. Although an early homozygous stop-codon (c.57G>A [W19X]) with no functional protein was found in the patient, about 70% of transferrin (Tf) was correctly glycosylated. Quantification of dolichol and unreduced polyprenol in the patient's fibroblasts demonstrated a high polyprenol/dolichol ratio with normal amounts of dolichol, indicating that high polyprenol levels might compete with dolichol for the initiation of N-glycan assembly but without supporting normal glycosylation and that there must be an alternative pathway for dolichol biosynthesis.
Collapse
Affiliation(s)
- J.E.H. Gründahl
- Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin—Allgemeine Pädiatrie, Münster, Germany
| | - Z. Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - S. Rust
- Leibniz-Institut für Arterioskleroseforschung, Münster, Germany
| | - J. Reunert
- Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin—Allgemeine Pädiatrie, Münster, Germany
| | - B. Müller
- Department of Pediatrics, University Hospital RWTH Aachen, Germany
| | - I. Du Chesne
- Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin—Allgemeine Pädiatrie, Münster, Germany
| | - K. Zerres
- Institute of Human Genetics, University Hospital RWTH Aachen, Germany
| | | | - N. Ortiz-Brüchle
- Institute of Human Genetics, University Hospital RWTH Aachen, Germany
| | - M.G. Häusler
- Department of Pediatrics, University Hospital RWTH Aachen, Germany
| | - J. Siedlecka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - E. Swiezewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - C.R.H. Raetz
- Department of Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - T. Marquardt
- Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin—Allgemeine Pädiatrie, Münster, Germany
- Corresponding author at: Klinik für Kinder- und Jugendmedizin, Albert-Schweitzer-Str. 33, 48149 Münster, Germany. Fax: +49 251 835 6085. (T. Marquardt)
| |
Collapse
|
3
|
Vleugels W, Duvet S, Peanne R, Mir AM, Cacan R, Michalski JC, Matthijs G, Foulquier F. Identification of phosphorylated oligosaccharides in cells of patients with a congenital disorders of glycosylation (CDG-I). Biochimie 2011; 93:823-33. [PMID: 21315133 DOI: 10.1016/j.biochi.2011.01.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 01/29/2011] [Indexed: 11/24/2022]
Abstract
Protein N-glycosylation is initiated by the dolichol cycle in which the oligosaccharide precursor Glc(3)Man(9)GlcNAc(2)-PP-dolichol is assembled in the endoplasmic reticulum (ER). One critical step in the dolichol cycle concerns the availability of Dol-P at the cytosolic face of the ER membrane. In RFT1 cells, the lipid-linked oligosaccharide (LLO) intermediate Man(5)GlcNAc(2)-PP-Dol accumulates at the cytosolic face of the ER membrane. Since Dol-P is a rate-limiting intermediate during protein N-glycosylation, continuous accumulation of Man(5)GlcNAc(2)-PP-Dol would block the dolichol cycle. Hence, we investigated the molecular mechanisms by which accumulating Man(5)GlcNAc(2)-PP-Dol could be catabolized in RFT1 cells. On the basis of metabolic labeling experiments and in comparison to human control cells, we identified phosphorylated oligosaccharides (POS), not found in human control cells and present evidence that they originate from the accumulating LLO intermediates. In addition, POS were also detected in other CDG patients' cells accumulating specific LLO intermediates at different cellular locations. Moreover, the enzymatic activity that hydrolyses oligosaccharide-PP-Dol into POS was identified in human microsomal membranes and required Mn(2+) for optimal activity. In CDG patients' cells, we thus identified and characterized POS that could result from the catabolism of accumulating LLO intermediates.
Collapse
Affiliation(s)
- Wendy Vleugels
- Laboratory for Molecular Diagnosis, Center for Human Genetics, University of Leuven, B-3000 Leuven, Belgium
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Cantagrel V, Lefeber DJ, Ng BG, Guan Z, Silhavy JL, Bielas SL, Lehle L, Hombauer H, Adamowicz M, Swiezewska E, De Brouwer AP, Blümel P, Sykut-Cegielska J, Houliston S, Swistun D, Ali BR, Dobyns WB, Babovic-Vuksanovic D, van Bokhoven H, Wevers RA, Raetz CRH, Freeze HH, Morava E, Al-Gazali L, Gleeson JG. SRD5A3 is required for converting polyprenol to dolichol and is mutated in a congenital glycosylation disorder. Cell 2010; 142:203-17. [PMID: 20637498 DOI: 10.1016/j.cell.2010.06.001] [Citation(s) in RCA: 204] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2010] [Revised: 03/26/2010] [Accepted: 05/06/2010] [Indexed: 02/08/2023]
Abstract
N-linked glycosylation is the most frequent modification of secreted and membrane-bound proteins in eukaryotic cells, disruption of which is the basis of the congenital disorders of glycosylation (CDGs). We describe a new type of CDG caused by mutations in the steroid 5alpha-reductase type 3 (SRD5A3) gene. Patients have mental retardation and ophthalmologic and cerebellar defects. We found that SRD5A3 is necessary for the reduction of the alpha-isoprene unit of polyprenols to form dolichols, required for synthesis of dolichol-linked monosaccharides, and the oligosaccharide precursor used for N-glycosylation. The presence of residual dolichol in cells depleted for this enzyme suggests the existence of an unexpected alternative pathway for dolichol de novo biosynthesis. Our results thus suggest that SRD5A3 is likely to be the long-sought polyprenol reductase and reveal the genetic basis of one of the earliest steps in protein N-linked glycosylation.
Collapse
Affiliation(s)
- Vincent Cantagrel
- Neurogenetics Laboratory, Institute for Genomic Medicine, Howard Hughes Medical Institute, Department of Neurosciences and Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Hypoglycosylation due to dolichol metabolism defects. Biochim Biophys Acta Mol Basis Dis 2009; 1792:888-95. [DOI: 10.1016/j.bbadis.2009.01.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2008] [Revised: 01/21/2009] [Accepted: 01/26/2009] [Indexed: 11/22/2022]
|
6
|
Jones MB, Rosenberg JN, Betenbaugh MJ, Krag SS. Structure and synthesis of polyisoprenoids used in N-glycosylation across the three domains of life. Biochim Biophys Acta Gen Subj 2009; 1790:485-94. [PMID: 19348869 DOI: 10.1016/j.bbagen.2009.03.030] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 03/26/2009] [Accepted: 03/30/2009] [Indexed: 01/11/2023]
Abstract
N-linked protein glycosylation was originally thought to be specific to eukaryotes, but evidence of this post-translational modification has now been discovered across all domains of life: Eucarya, Bacteria, and Archaea. In all cases, the glycans are first assembled in a step-wise manner on a polyisoprenoid carrier lipid. At some stage of lipid-linked oligosaccharide synthesis, the glycan is flipped across a membrane. Subsequently, the completed glycan is transferred to specific asparagine residues on the protein of interest. Interestingly, though the N-glycosylation pathway seems to be conserved, the biosynthetic pathways of the polyisoprenoid carriers, the specific structures of the carriers, and the glycan residues added to the carriers vary widely. In this review we will elucidate how organisms in each basic domain of life synthesize the polyisoprenoids that they utilize for N-linked glycosylation and briefly discuss the subsequent modifications of the lipid to generate a lipid-linked oligosaccharide.
Collapse
Affiliation(s)
- Meredith B Jones
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | | | | |
Collapse
|
7
|
Kranz C, Jungeblut C, Denecke J, Erlekotte A, Sohlbach C, Debus V, Kehl HG, Harms E, Reith A, Reichel S, Grobe H, Hammersen G, Schwarzer U, Marquardt T. A defect in dolichol phosphate biosynthesis causes a new inherited disorder with death in early infancy. Am J Hum Genet 2007; 80:433-40. [PMID: 17273964 PMCID: PMC1821118 DOI: 10.1086/512130] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Accepted: 12/29/2006] [Indexed: 11/04/2022] Open
Abstract
The following study describes the discovery of a new inherited metabolic disorder, dolichol kinase (DK1) deficiency. DK1 is responsible for the final step of the de novo biosynthesis of dolichol phosphate. Dolichol phosphate is involved in several glycosylation reactions, such as N-glycosylation, glycosylphosphatidylinositol (GPI)-anchor biosynthesis, and C- and O-mannosylation. We identified four patients who were homozygous for one of two mutations (c.295T-->A [99Cys-->Ser] or c.1322A-->C [441Tyr-->Ser]) in the corresponding hDK1 gene. The residual activity of mutant DK1 was 2%-4% when compared with control cells. The mutated alleles failed to complement the temperature-sensitive phenotype of DK1-deficient yeast cells, whereas the wild-type allele restored the normal growth phenotype. Affected patients present with a very severe clinical phenotype, with death in early infancy. Two of the patients died from dilative cardiomyopathy.
Collapse
|
8
|
Schenk B, Fernandez F, Waechter CJ. The ins(ide) and out(side) of dolichyl phosphate biosynthesis and recycling in the endoplasmic reticulum. Glycobiology 2001; 11:61R-70R. [PMID: 11425794 DOI: 10.1093/glycob/11.5.61r] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The precursor oligosaccharide donor for protein N-glycosylation in eukaryotes, Glc3Man9GlcNAc(2)-P-P-dolichol, is synthesized in two stages on both leaflets of the rough endoplasmic reticulum (ER). There is good evidence that the level of dolichyl monophosphate (Dol-P) is one rate-controlling factor in the first stage of the assembly process. In the current topological model it is proposed that ER proteins (flippases) then mediate the transbilayer movement of Man-P-Dol, Glc-P-Dol, and Man5GlcNAc(2)-P-P-Dol from the cytoplasmic leaflet to the lumenal leaflet. The rate of flipping of the three intermediates could plausibly influence the conversion of Man5GlcNAc(2)-P-P-Dol to Glc3Man(9)GlcNAc(2)-P-P-Dol in the second stage on the lumenal side of the rough ER. This article reviews the current understanding of the enzymes involved in the de novo biosynthesis of Dol-P and other polyisoprenoid glycosyl carrier lipids and speculates about the role of membrane proteins and enzymes that could be involved in the transbilayer movement of the lipid intermediates and the recycling of Dol-P and Dol-P-P discharged during glycosylphosphatidylinositol anchor biosynthesis, N-glycosylation, and O- and C-mannosylation reactions on the lumenal surface of the rough ER.
Collapse
Affiliation(s)
- B Schenk
- Institute for Microbiology, ETH Zurich, 8092 Zurich, Switzerland
| | | | | |
Collapse
|
9
|
A Chinese hamster ovary cell mutant F2A8 utilizes polyprenol rather than dolichol for its lipid-dependent asparagine-linked glycosylation reactions. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)38038-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
10
|
Rodríguez P, Bello O, Apitz-Castro R. Glycoprotein biosynthesis by human normal platelets. BIOCHEMICAL MEDICINE AND METABOLIC BIOLOGY 1987; 37:197-204. [PMID: 3593591 DOI: 10.1016/0885-4505(87)90027-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Incorporation of radioactive Man, Gal, Fuc, Glc-N, and NANA into washed human normal platelets and endogenous glycoproteins has been found. Both parameters were time dependent. Analysis of hydrolyzed labeled glycoproteins by paper chromatography revealed that the radioactive monosaccharide incubated with the platelets had not been converted into other sugars. Acid hydrolysis demonstrates the presence of a glycosidic linkage. All the effort directed to the demonstration of the existence of a lipid-sugar intermediate in intact human platelets yielded negative results for Man and Glc-N used as precursors. The incorporation of these sugars into glycoproteins is insensitive to bacitracin, suggesting no involvement of lipid-linked saccharides in the synthesis of glycoproteins in human blood platelets. The absence of inhibition of the glycosylation process in the presence of cycloheximide suggests that the sugars are added to proteins present in the intact platelets. These results support the contention that glycoprotein biosynthesis in human blood platelets observed under our experimental conditions is effected through direct sugar nucleotide glycosylation.
Collapse
|
11
|
Control of N-linked carbohydrate unit synthesis in thyroid endoplasmic reticulum by membrane organization and dolichyl phosphate availability. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)66931-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
12
|
Krag SS. Chapter 5 Mechanisms and Functional Role of Glycosylation in Membrane Protein Synthesis. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/s0070-2161(08)60327-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
|
13
|
Rip JW, Rupar CA, Ravi K, Carroll KK. Distribution, metabolism and function of dolichol and polyprenols. Prog Lipid Res 1985; 24:269-309. [PMID: 2819898 DOI: 10.1016/0163-7827(85)90008-6] [Citation(s) in RCA: 126] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Polyisoprenoid alcohols consisting of 9 or more isoprene units are present in all living cells. They can be fully unsaturated (polyprenols) or alpha-saturated (dolichol). Dolichol forms may have additional saturation at or near the omega-end. Some species contain ony dolichol or only polyprenols while others have nearly equal amounts of both types. Some polyisoprenoid alcohols consist entirely of trans isoprene units but most, including dolichol, contain both trans and cis units. Considerable advances in lipid methodology have occurred since the first review of polyisoprenoid alcohols by Hemming in 1974. For example, direct analysis of both dolichol and Dol-P by HPLC has replaced earlier methods which were often both insensitive and inaccurate. The availability of radiolabeled dolichol and polyprenols has facilitated studies concerning the metabolism and distribution of these compounds. Those studies suggest that only a small portion of the dolichol present in cells is likely to be involved in glycosylation. Polyisoprenoid alcohols are usually present at a family of homologues where each differs in size by one isoprene unit. Little or no size related specificity has been observed for any reaction involving dolichol or polyisoprenol intermediates. The overall length of polyisoprenoid alcohols may, however, affect the manner in which these compounds influence the physical and biochemical properties of membranes. Studies on the biosynthetic pathway leading from cis, trans Pol-PP by phosphatase action. The formation of the dolichol backbone from a polyprenol requires the action of an additional enzyme, an alpha-saturase. This enzyme does not always act at the level of a single common substrate, since Pol-PP, Pol-P, and polyprenol all appear to be utilized as substrates. The major product of the de novo pathway differs among different species. Dol-P would appear to be the most energy efficient end-product since it can participate directly in glycoprotein formation. Most often, however, Dol-P is not the major product of metabolic labeling experiments. In some cases, dolichol is formed so that rephosphorylation is required to provide Dol-P for participation in glycoprotein formation. The kinase responsible for this phosphorylation appears to bypass the considerable stores of dolichol present in tissues (i.e. sea urchin eggs) in favor of dolichol derived directly from de novo synthesis. Although HMGR is a major regulatory component of the pathway leading to polyisoprenoid alcohols and cholesterol, control is most often not co-ordinated.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
|
14
|
|
15
|
Brain dolichyl pyrophosphate phosphatase. Solubilization, characterization, and differentiation from dolichyl monophosphate phosphatase activity. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(17)42641-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
16
|
|
17
|
Belocopitow E, Boscoboinik D. Dolichyl-phosphate phosphatase and dolichyl-diphosphate phosphatase in rat-liver microsomes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 125:167-73. [PMID: 6125387 DOI: 10.1111/j.1432-1033.1982.tb06664.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Dolichyl-phosphate phosphatase and dolichyl-diphosphate phosphatase activities of a liver-cell microsomal preparation were solubilized by treatment with Triton X-100. The 100,000 X g supernatant was then passed through a column of Sepharose-4B--concanavalin A. Both enzyme activities were found in the percolate. This treatment eliminated inhibition by ATP and glucose 6-phosphate in both phosphatase activities. In each case the activities were inhibited by higher concentrations of enzyme preparation due to the presence of phospholipids. The inhibitory effects of either phosphatidylcholine or phosphatidylethanolamine were due to competition for detergent. On the other hand, the effect produced by phosphatidic acid appeared to be different, since it did not change the optimal concentration of Triton X-100 for the two enzymes. Dolichyl-phosphate phosphatase was strongly inhibited by both Pi and PPi, whereas dolichyl-diphosphate phosphatase was only slightly inhibited by Pi and not at all by PPi. Dolichyl-diphosphate phosphatase was more inhibited by divalent cations than dolichyl-phosphate phosphatase. The apparent Km of dolichyl-phosphate phosphatase for dolichyl phosphate was 0.15 mM. Dolichol also inhibited dolichyl-phosphate phosphatase, but it produced a stronger inhibition on dolichyl-diphosphate phosphatase. The inhibitory effect of dolichol was not entirely due to detergent competition.
Collapse
|
18
|
Schwarz RT, Datema R. The lipid pathway of protein glycosylation and its inhibitors: the biological significance of protein-bound carbohydrates. Adv Carbohydr Chem Biochem 1982; 40:287-379. [PMID: 6188345 DOI: 10.1016/s0065-2318(08)60111-0] [Citation(s) in RCA: 151] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
19
|
Appelkvist EL, Chojnacki T, Dallner G. Dolichol(C55) mono- and pyrophosphatases of the rat liver. Biosci Rep 1981. [DOI: 10.1007/bf01116277] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Affiliation(s)
- E. L. Appelkvist
- Department of Biochemistry, University of Stockholm, Sweden
- Department of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Department of Pathology, Karolinska Institutet, Stockholm, Sweden
| | - T. Chojnacki
- Department of Biochemistry, University of Stockholm, Sweden
- Department of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Department of Pathology, Karolinska Institutet, Stockholm, Sweden
| | - G. Dallner
- Department of Biochemistry, University of Stockholm, Sweden
- Department of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Department of Pathology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
20
|
Ramachandran CK, Hignite CE, Gray SL, Melnykovych G. Evidence for the stimulation of dolichol and mannolipid synthesis by glucocorticoids in HeLa cells. Biochem J 1981; 198:23-8. [PMID: 7325998 PMCID: PMC1163206 DOI: 10.1042/bj1980023] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The effects of addition of 1 microM-dexamethasone on the rate of transfer of mannose from GDP-mannose into mannolipid have been studied in HeLa cell cultures. Concurrent with an increase in incorporation of mannose into glycoproteins, the incorporation of mannose from GDP-mannose in vitro into mannolipid and dolichol-linked oligosaccharides was increased after dexamethasone treatment. Stimulation of mannolipid synthesis showed a correlation with the 11 beta, 17 alpha, 21-trihydroxy structure of C21 steroids. Dexamethasone treatment also resulted in an increased incorporation of acetate into dolichol and dolichyl phosphate. The results suggest that the effect of dexamethasone on the cell-surface glycoprotein accumulation is related to increased sugar-linked dolichol synthesis.
Collapse
|