Base de dados : MEDLINE
Pesquisa : D02.455.849.690.700.710 [Categoria DeCS]
Referências encontradas : 127 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 13 ir para página                         

  1 / 127 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27015803
[Au] Autor:Taguchi Y; Fujinami D; Kohda D
[Ad] Endereço:From the Division of Structural Biology and.
[Ti] Título:Comparative Analysis of Archaeal Lipid-linked Oligosaccharides That Serve as Oligosaccharide Donors for Asn Glycosylation.
[So] Source:J Biol Chem;291(21):11042-54, 2016 May 20.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The glycosylation of asparagine residues is the predominant protein modification in all three domains of life. An oligosaccharide chain is preassembled on a lipid-phospho carrier and transferred onto asparagine residues by the action of a membrane-bound enzyme, oligosaccharyltransferase. The oligosaccharide donor for the oligosaccharyl transfer reaction is dolichol-diphosphate-oligosaccharide in Eukaryota and polyprenol-diphosphate-oligosaccharide in Eubacteria. The donor in some archaeal species was reportedly dolichol-monophosphate-oligosaccharide. Thus, the difference in the number of phosphate groups aroused interest in whether the use of the dolichol-monophosphate type donors is widespread in the domain Archaea. Currently, all of the archaeal species with identified oligosaccharide donors have belonged to the phylum Euryarchaeota. Here, we analyzed the donor structures of two species belonging to the phylum Crenarchaeota, Pyrobaculum calidifontis and Sulfolobus solfataricus, in addition to two species from the Euryarchaeota, Pyrococcus furiosus and Archaeoglobus fulgidus The electrospray ionization tandem mass spectrometry analyses confirmed that the two euryarchaeal oligosaccharide donors were the dolichol-monophosphate type and newly revealed that the two crenarchaeal oligosaccharide donors were the dolichol-diphosphate type. This novel finding is consistent with the hypothesis that the ancestor of Eukaryota is rooted within the TACK (Thaum-, Aig-, Cren-, and Korarchaeota) superphylum, which includes Crenarchaea. Our comprehensive study also revealed that one archaeal species could contain two distinct oligosaccharide donors for the oligosaccharyl transfer reaction. The A. fulgidus cells contained two oligosaccharide donors bearing oligosaccharide moieties with different backbone structures, and the S. solfataricus cells contained two oligosaccharide donors bearing stereochemically different dolichol chains.
[Mh] Termos MeSH primário: Archaea/metabolismo
Asparagina/metabolismo
Oligossacarídeos de Poli-Isoprenil Fosfato/química
Oligossacarídeos de Poli-Isoprenil Fosfato/metabolismo
[Mh] Termos MeSH secundário: Archaea/classificação
Proteínas Arqueais/metabolismo
Archaeoglobus fulgidus/metabolismo
Asparagina/química
Glicosilação
Hexosiltransferases/metabolismo
Proteínas de Membrana/metabolismo
Estrutura Molecular
Pyrobaculum/metabolismo
Pyrococcus furiosus/metabolismo
Espectrometria de Massas por Ionização por Electrospray
Sulfolobus solfataricus/metabolismo
Espectrometria de Massas em Tandem
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Membrane Proteins); 0 (Polyisoprenyl Phosphate Oligosaccharides); 7006-34-0 (Asparagine); EC 2.4.1.- (Hexosyltransferases); EC 2.4.99.18 (dolichyl-diphosphooligosaccharide - protein glycotransferase)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:170520
[Lr] Data última revisão:
170520
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160327
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M115.713156


  2 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:24062310
[Au] Autor:Harada Y; Buser R; Ngwa EM; Hirayama H; Aebi M; Suzuki T
[Ad] Endereço:From the Glycometabolome Team, Systems Glycobiology Research Group, RIKEN-Max Planck Joint Research Center, Global Research Cluster, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and.
[Ti] Título:Eukaryotic oligosaccharyltransferase generates free oligosaccharides during N-glycosylation.
[So] Source:J Biol Chem;288(45):32673-84, 2013 Nov 08.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Asparagine (N)-linked glycosylation regulates numerous cellular activities, such as glycoprotein quality control, intracellular trafficking, and cell-cell communications. In eukaryotes, the glycosylation reaction is catalyzed by oligosaccharyltransferase (OST), a multimembrane protein complex that is localized in the endoplasmic reticulum (ER). During N-glycosylation in the ER, the protein-unbound form of oligosaccharides (free oligosaccharides; fOSs), which is structurally related to N-glycan, is released into the ER lumen. However, the enzyme responsible for this process remains unidentified. Here, we demonstrate that eukaryotic OST generates fOSs. Biochemical and genetic analyses using mutant strains of Saccharomyces cerevisiae revealed that the generation of fOSs is tightly correlated with the N-glycosylation activity of OST. Furthermore, we present evidence that the purified OST complex can generate fOSs by hydrolyzing dolichol-linked oligosaccharide, the glycan donor substrate for N-glycosylation. The heterologous expression of a single subunit of OST from the protozoan Leishmania major in S. cerevisiae demonstrated that this enzyme functions both in N-glycosylation and generation of fOSs. This study provides insight into the mechanism of PNGase-independent formation of fOSs.
[Mh] Termos MeSH primário: Hexosiltransferases/metabolismo
Leishmania major/enzimologia
Proteínas de Membrana/metabolismo
Oligossacarídeos/metabolismo
Proteínas de Protozoários/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/enzimologia
[Mh] Termos MeSH secundário: Glicosilação
Hexosiltransferases/genética
Leishmania major/genética
Proteínas de Membrana/genética
Oligossacarídeos/genética
Oligossacarídeos de Poli-Isoprenil Fosfato/metabolismo
Proteínas de Protozoários/genética
Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Membrane Proteins); 0 (Oligosaccharides); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Protozoan Proteins); 0 (Saccharomyces cerevisiae Proteins); EC 2.4.1.- (Hexosyltransferases); EC 2.4.99.18 (dolichyl-diphosphooligosaccharide - protein glycotransferase)
[Em] Mês de entrada:1401
[Cu] Atualização por classe:151119
[Lr] Data última revisão:
151119
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130925
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M113.486985


  3 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:23720757
[Au] Autor:Jelk J; Gao N; Serricchio M; Signorell A; Schmidt RS; Bangs JD; Acosta-Serrano A; Lehrman MA; Bütikofer P; Menon AK
[Ad] Endereço:Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065, USA.
[Ti] Título:Glycoprotein biosynthesis in a eukaryote lacking the membrane protein Rft1.
[So] Source:J Biol Chem;288(28):20616-23, 2013 Jul 12.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mature dolichol-linked oligosaccharides (mDLOs) needed for eukaryotic protein N-glycosylation are synthesized by a multistep pathway in which the biosynthetic lipid intermediate Man5GlcNAc2-PP-dolichol (M5-DLO) flips from the cytoplasmic to the luminal face of the endoplasmic reticulum. The endoplasmic reticulum membrane protein Rft1 is intimately involved in mDLO biosynthesis. Yeast genetic analyses implicated Rft1 as the M5-DLO flippase, but because biochemical tests challenged this assignment, the function of Rft1 remains obscure. To understand the role of Rft1, we sought to analyze mDLO biosynthesis in vivo in the complete absence of the protein. Rft1 is essential for yeast viability, and no Rft1-null organisms are currently available. Here, we exploited Trypanosoma brucei (Tb), an early diverging eukaryote whose Rft1 homologue functions in yeast. We report that TbRft1-null procyclic trypanosomes grow nearly normally. They have normal steady-state levels of mDLO and significant N-glycosylation, indicating robust M5-DLO flippase activity. Remarkably, the mutant cells have 30-100-fold greater steady-state levels of M5-DLO than wild-type cells. All N-glycans in the TbRft1-null cells originate from mDLO indicating that the M5-DLO excess is not available for glycosylation. These results suggest that rather than facilitating M5-DLO flipping, Rft1 facilitates conversion of M5-DLO to mDLO by another mechanism, possibly by acting as an M5-DLO chaperone.
[Mh] Termos MeSH primário: Células Eucarióticas/metabolismo
Glicoproteínas/metabolismo
Proteínas de Membrana/metabolismo
Proteínas de Protozoários/metabolismo
Trypanosoma brucei brucei/metabolismo
[Mh] Termos MeSH secundário: Eletroforese em Gel de Poliacrilamida
Retículo Endoplasmático/metabolismo
Citometria de Fluxo
Glucose/farmacologia
Glicoproteínas/genética
Glicosilação
Glicoproteínas de Membrana Associadas ao Lisossomo/metabolismo
Glicoproteínas de Membrana/genética
Glicoproteínas de Membrana/metabolismo
Proteínas de Membrana/genética
Proteínas de Membrana Transportadoras/genética
Proteínas de Membrana Transportadoras/metabolismo
Microscopia de Fluorescência
Modelos Biológicos
Mutação
Oligossacarídeos de Poli-Isoprenil Fosfato/metabolismo
Polissacarídeos/metabolismo
Biossíntese de Proteínas
Proteínas de Protozoários/genética
Saccharomyces cerevisiae/genética
Saccharomyces cerevisiae/crescimento & desenvolvimento
Saccharomyces cerevisiae/metabolismo
Proteínas de Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
Transformação Genética
Trypanosoma brucei brucei/genética
Trypanosoma brucei brucei/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Glycoproteins); 0 (Lysosome-Associated Membrane Glycoproteins); 0 (Membrane Glycoproteins); 0 (Membrane Proteins); 0 (Membrane Transport Proteins); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Polysaccharides); 0 (Protozoan Proteins); 0 (RFT1 protein, S cerevisiae); 0 (Saccharomyces cerevisiae Proteins); 119913-05-2 (mannosyl(5)-N-acetyl(2)-glucose diphosphate dolichol); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1309
[Cu] Atualização por classe:161202
[Lr] Data última revisão:
161202
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130531
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M113.479642


  4 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:19494107
[Au] Autor:Rush JS; Gao N; Lehrman MA; Matveev S; Waechter CJ
[Ad] Endereço:Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536, USA.
[Ti] Título:Suppression of Rft1 expression does not impair the transbilayer movement of Man5GlcNAc2-P-P-dolichol in sealed microsomes from yeast.
[So] Source:J Biol Chem;284(30):19835-42, 2009 Jul 24.
[Is] ISSN:0021-9258
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:To further evaluate the role of Rft1 in the transbilayer movement of Man(5)GlcNAc(2)-P-P-dolichol (M5-DLO), a series of experiments was conducted with intact cells and sealed microsomal vesicles. First, an unexpectedly large accumulation (37-fold) of M5-DLO was observed in Rft1-depleted cells (YG1137) relative to Glc(3)Man(9)GlcNAc(2)-P-P-Dol in wild type (SS328) cells when glycolipid levels were compared by fluorophore-assisted carbohydrate electrophoresis analysis. When sealed microsomes from wild type cells and cells depleted of Rft1 were incubated with GDP-[(3)H]mannose or UDP-[(3)H]GlcNAc in the presence of unlabeled GDP-Man, no difference was observed in the rate of synthesis of [(3)H]Man(9)GlcNAc(2)-P-P-dolichol or Man(9)[(3)H]GlcNAc(2)-P-P-dolichol, respectively. In addition, no difference was seen in the level of M5-DLO flippase activity in sealed wild type and Rft1-depleted microsomal vesicles when the activity was assessed by the transport of GlcNAc(2)-P-P-Dol(15), a water-soluble analogue. The entry of the analogue into the lumenal compartment was confirmed by demonstrating that [(3)H]chitobiosyl units were transferred to endogenous peptide acceptors via the yeast oligosaccharyltransferase when sealed vesicles were incubated with [(3)H]GlcNAc(2)-P-P-Dol(15) in the presence of an exogenously supplied acceptor peptide. In addition, several enzymes involved in Dol-P and lipid intermediate biosynthesis were found to be up-regulated in Rft1-depleted cells. All of these results indicate that although Rft1 may play a critical role in vivo, depletion of this protein does not impair the transbilayer movement of M5-DLO in sealed microsomal fractions prepared from disrupted cells.
[Mh] Termos MeSH primário: Glicoproteínas de Membrana/genética
Glicoproteínas de Membrana/metabolismo
Proteínas de Membrana Transportadoras/genética
Proteínas de Membrana Transportadoras/metabolismo
Microssomos/metabolismo
Oligossacarídeos de Poli-Isoprenil Fosfato/análise
Oligossacarídeos de Poli-Isoprenil Fosfato/metabolismo
Proteínas de Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Alquil e Aril Transferases/metabolismo
Transporte Biológico
Dolicol Monofosfato Manose/metabolismo
Regulação Bacteriana da Expressão Gênica
Glucose/metabolismo
Hexosiltransferases/metabolismo
Manose/metabolismo
Proteínas de Membrana/metabolismo
Microssomos/química
Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo
Monossacarídeos de Poli-Isoprenil Fosfato/metabolismo
Saccharomyces cerevisiae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Membrane Glycoproteins); 0 (Membrane Proteins); 0 (Membrane Transport Proteins); 0 (Polyisoprenyl Phosphate Monosaccharides); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (RFT1 protein, S cerevisiae); 0 (Saccharomyces cerevisiae Proteins); 119913-05-2 (mannosyl(5)-N-acetyl(2)-glucose diphosphate dolichol); 55598-56-6 (Dolichol Monophosphate Mannose); 55607-88-0 (dolichol-D-glucosylmonophosphate); EC 2.4.1.- (Hexosyltransferases); EC 2.4.99.18 (dolichyl-diphosphooligosaccharide - protein glycotransferase); EC 2.5.- (Alkyl and Aryl Transferases); EC 2.5.1.- (cis-isoprenyltransferase); EC 2.7.1.- (Phosphotransferases (Alcohol Group Acceptor)); EC 2.7.1.108 (dolichol kinase); IY9XDZ35W2 (Glucose); PHA4727WTP (Mannose)
[Em] Mês de entrada:0909
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:090605
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M109.000893


  5 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:19129492
[Au] Autor:Sanyal S; Menon AK
[Ad] Endereço:Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA.
[Ti] Título:Specific transbilayer translocation of dolichol-linked oligosaccharides by an endoplasmic reticulum flippase.
[So] Source:Proc Natl Acad Sci U S A;106(3):767-72, 2009 Jan 20.
[Is] ISSN:1091-6490
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The oligosaccharide donor for protein N-glycosylation, Glc(3)Man(9)GlcNAc(2)-PP-dolichol, is synthesized via a multistep pathway that starts on the cytoplasmic face of the endoplasmic reticulum (ER) and ends in the lumen where the glycosylation reaction occurs. This necessitates transbilayer translocation or flipping of the lipid intermediate Man(5)GlcNAc(2)-PP-dolichol (M5-DLO) across the ER membrane. The mechanism by which M5-DLO-or any other lipid-is flipped across the ER is unknown, except that specific transport proteins or flippases are required. We recently demonstrated M5-DLO flipping activity in proteoliposomes reconstituted from detergent-solubilized ER membrane proteins and showed that it was ATP-independent and required a trypsin-sensitive protein that sedimented at approximately 4S. By using an activity-enriched fraction devoid of glycerophospholipid flippase activity, we now report that M5-DLO is rapidly flipped in the reconstituted system with a time constant tau <2 min, whereas its triantennary structural isomer is flipped slowly with tau >200 min. DLOs larger than M5-DLO are also poorly translocated, with tau ranging from approximately 10 min to >200 min. We conclude that (i) the number and arrangement of mannoses in the DLO glycan has a profound effect on the ability of the DLO to be translocated by the flippase, (ii) glycan size per se does not dictate whether a DLO will be flipped, and (iii) the flippase is highly specific for M5-DLO. Our results suggest a simple structural model for the interaction between the DLO head group and the flippase.
[Mh] Termos MeSH primário: Retículo Endoplasmático/metabolismo
Bicamadas Lipídicas/metabolismo
Proteínas de Transferência de Fosfolipídeos/fisiologia
Oligossacarídeos de Poli-Isoprenil Fosfato/metabolismo
[Mh] Termos MeSH secundário: Animais
Transporte Biológico
Glicosilação
Proteolipídeos/metabolismo
Ratos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Lipid Bilayers); 0 (Phospholipid Transfer Proteins); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Proteolipids); 0 (proteoliposomes); 119913-05-2 (mannosyl(5)-N-acetyl(2)-glucose diphosphate dolichol)
[Em] Mês de entrada:0902
[Cu] Atualização por classe:161019
[Lr] Data última revisão:
161019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:090109
[St] Status:MEDLINE
[do] DOI:10.1073/pnas.0810225106


  6 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:17674393
[Au] Autor:Ghalit N; Reichwein JF; Hilbers HW; Breukink E; Rijkers DT; Liskamp RM
[Ad] Endereço:Medicinal Chemistry & Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands.
[Ti] Título:Synthesis of bicyclic alkene-/alkane-bridged nisin mimics by ring-closing metathesis and their biochemical evaluation as lipid II binders: toward the design of potential novel antibiotics.
[So] Source:Chembiochem;8(13):1540-54, 2007 Sep 03.
[Is] ISSN:1439-4227
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:This report describes the design, synthesis, and biochemical evaluation of alkene- and alkane-bridged AB(C)-ring mimics of the lantibiotic nisin. Nisin belongs to a class of natural antimicrobial peptides, and has a unique mode of action: its AB(C)-ring system binds to the pyrophosphate moiety of lipid II. This mode of action was the rationale for the design of smaller nisin-derived peptides to obtain novel potential antibiotics. As a conformational constraint the thioether bridge was mimicked by an alkene- or alkane isostere. The peptides of the linear individual ring precursors were synthesized on solid support or in solution, and cyclized by ring-closing metathesis in solution with overall yields of between 36 and 89 %. The individual alkene-bridged macrocycles were assembled in solution by using carbodiimide-based synthesis protocols for the corresponding AB(C)-ring mimics. These compounds were tested for their binding affinity toward lipid II by evaluation of their potency to inhibit nisin-induced carboxyfluorescein release from large unilamellar vesicles. It was found that these AB(C)-ring mimics were not able to induce membrane leakage; however, they acted by inhibiting nisin-induced carboxyfluorescein release; this indicates their affinity toward lipid II. These results imply that an alkene or alkane moiety is a suitable thioether bridge mimic.
[Mh] Termos MeSH primário: Alcanos/química
Alcenos/química
Antibacterianos/síntese química
Desenho de Drogas
Mimetismo Molecular
Nisina/síntese química
Fragmentos de Peptídeos/metabolismo
Uridina Difosfato Ácido N-Acetilmurâmico/análogos & derivados
[Mh] Termos MeSH secundário: Alcanos/síntese química
Alcenos/síntese química
Antibacterianos/química
Antibacterianos/metabolismo
Catálise
Cromatografia Líquida de Alta Pressão
Cromatografia em Camada Delgada
Computadores Moleculares
Ciclização
Fluoresceínas/química
Fluoresceínas/metabolismo
Modelos Moleculares
Nisina/química
Nisina/metabolismo
Fragmentos de Peptídeos/síntese química
Fragmentos de Peptídeos/química
Fosfatidilcolinas/metabolismo
Oligossacarídeos de Poli-Isoprenil Fosfato
Estereoisomerismo
Lipossomas Unilamelares/química
Lipossomas Unilamelares/metabolismo
Uridina Difosfato Ácido N-Acetilmurâmico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Alkanes); 0 (Alkenes); 0 (Anti-Bacterial Agents); 0 (Fluoresceins); 0 (Peptide Fragments); 0 (Phosphatidylcholines); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Unilamellar Liposomes); 0 (Uridine Diphosphate N-Acetylmuramic Acid); 0 (muramyl-NAc-(pentapeptide)pyrophosphoryl-undecaprenol); 1414-45-5 (Nisin); 3301-79-9 (6-carboxyfluorescein); EDS2L3ODLV (1,2-oleoylphosphatidylcholine)
[Em] Mês de entrada:0710
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:070804
[St] Status:MEDLINE


  7 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:16100113
[Au] Autor:Bickel T; Lehle L; Schwarz M; Aebi M; Jakob CA
[Ad] Endereço:Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
[Ti] Título:Biosynthesis of lipid-linked oligosaccharides in Saccharomyces cerevisiae: Alg13p and Alg14p form a complex required for the formation of GlcNAc(2)-PP-dolichol.
[So] Source:J Biol Chem;280(41):34500-6, 2005 Oct 14.
[Is] ISSN:0021-9258
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:N-Glycosylation in the endoplasmic reticulum is an essential protein modification and highly conserved in evolution from yeast to man. Here we identify and characterize two essential yeast proteins having homology to bacterial glycosyltransferases, designated Alg13p and Alg14p, as being required for the formation of GlcNAc(2)-PP-dolichol (Dol), the second step in the biosynthesis of the unique lipid-linked core oligosaccharide. Down-regulation of each gene led to a defect in protein N-glycosylation and an accumulation of GlcNAc(1)-PP-Dol in vivo as revealed by metabolic labeling with [(3)H]glucosamine. Microsomal membranes from cells repressed for ALG13 or ALG14, as well as detergent-solubilized extracts thereof, were unable to catalyze the transfer of N-acetylglucosamine from UDP-GlcNAc to [(14)C]GlcNAc(1)-PP-Dol, but did not impair the formation of GlcNAc(1)-PP-Dol or GlcNAc-GPI. Immunoprecipitating Alg13p from solubilized extracts resulted in the formation of GlcNAc(2)-PP-Dol but required Alg14p for activity, because an Alg13p immunoprecipitate obtained from cells in which ALG14 was down-regulated lacked this activity. In Western blot analysis it was demonstrated that Alg13p, for which no well defined transmembrane segment has been predicted, localizes both to the membrane and cytosol; the latter form, however, is enzymatically inactive. In contrast, Alg14p is exclusively membrane-bound. Repression of the ALG14 gene causes a depletion of Alg13p from the membrane. By affinity chromatography on IgG-Sepharose using Alg14-ZZ as bait, we demonstrate that Alg13-myc co-fractionates with Alg14-ZZ. The data suggest that Alg13p associates with Alg14p to a complex forming the active transferase catalyzing the biosynthesis of GlcNAc(2)-PP-Dol.
[Mh] Termos MeSH primário: Lipídeos/química
N-Acetilglucosaminiltransferases/fisiologia
Oligossacarídeos/química
Oligossacarídeos de Poli-Isoprenil Fosfato/química
Proteínas de Saccharomyces cerevisiae/fisiologia
Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Western Blotting
Membrana Celular/metabolismo
Cromatografia de Afinidade
Citosol/metabolismo
Detergentes/farmacologia
Regulação para Baixo
Glicosilação
Imunoglobulina G/química
Imunoprecipitação
Membranas Intracelulares/metabolismo
Microssomos/metabolismo
N-Acetilglucosaminiltransferases/química
Fases de Leitura Aberta
Plasmídeos/metabolismo
Ligação Proteica
Estrutura Terciária de Proteína
Proteínas de Saccharomyces cerevisiae/química
Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Detergents); 0 (Immunoglobulin G); 0 (Lipids); 0 (Oligosaccharides); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Saccharomyces cerevisiae Proteins); 59694-82-5 (dolichyl-diphosphate-di-N-acetylchitobiose); EC 2.4.1.- (Alg13 protein, S cerevisiae); EC 2.4.1.- (Alg14 protein, S cerevisiae); EC 2.4.1.- (N-Acetylglucosaminyltransferases)
[Em] Mês de entrada:0512
[Cu] Atualização por classe:061115
[Lr] Data última revisão:
061115
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:050816
[St] Status:MEDLINE


  8 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:16100110
[Au] Autor:Gao XD; Tachikawa H; Sato T; Jigami Y; Dean N
[Ad] Endereço:Research Center for Glycoscience, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan.
[Ti] Título:Alg14 recruits Alg13 to the cytoplasmic face of the endoplasmic reticulum to form a novel bipartite UDP-N-acetylglucosamine transferase required for the second step of N-linked glycosylation.
[So] Source:J Biol Chem;280(43):36254-62, 2005 Oct 28.
[Is] ISSN:0021-9258
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:N-linked glycosylation requires the synthesis of an evolutionarily conserved lipid-linked oligosaccharide (LLO) precursor that is essential for glycoprotein folding and stability. Despite intense research, several of the enzymes required for LLO synthesis have not yet been identified. Here we show that two poorly characterized yeast proteins known to be required for the synthesis of the LLO precursor, GlcNAc2-PP-dolichol, interact to form an unusual hetero-oligomeric UDP-GlcNAc transferase. Alg13 contains a predicted catalytic domain, but lacks any membrane-spanning domains. Alg14 spans the membrane but lacks any sequences predicted to play a direct role in sugar catalysis. We show that Alg14 functions as a membrane anchor that recruits Alg13 to the cytosolic face of the ER, where catalysis of GlcNAc2-PP-dol occurs. Alg13 and Alg14 physically interact and under normal conditions, are associated with the ER membrane. Overexpression of Alg13 leads to its cytosolic partitioning, as does reduction of Alg14 levels. Concomitant Alg14 overproduction suppresses this cytosolic partitioning of Alg13, demonstrating that Alg14 is both necessary and sufficient for the ER localization of Alg13. Further evidence for the functional relevance of this interaction comes from our demonstration that the human ALG13 and ALG14 orthologues fail to pair with their yeast partners, but when co-expressed in yeast can functionally complement the loss of either ALG13 or ALG14. These results demonstrate that this novel UDP-GlcNAc transferase is a unique eukaryotic ER glycosyltransferase that is comprised of at least two functional polypeptides, one that functions in catalysis and the other as a membrane anchor.
[Mh] Termos MeSH primário: Asparagina/química
Citoplasma/metabolismo
Retículo Endoplasmático/metabolismo
N-Acetilglucosaminiltransferases/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Western Blotting
Catálise
Domínio Catalítico
Citosol/metabolismo
DNA Complementar/metabolismo
Evolução Molecular
Proteínas Fúngicas/química
Teste de Complementação Genética
Glicosilação
Proteínas de Fluorescência Verde/metabolismo
Seres Humanos
Imunoprecipitação
Lipídeos/química
Microscopia de Fluorescência
Dados de Sequência Molecular
N-Acetilglucosaminiltransferases/química
Oligossacarídeos/química
Peptídeos/química
Oligossacarídeos de Poli-Isoprenil Fosfato/química
Ligação Proteica
Estrutura Terciária de Proteína
Proteínas Recombinantes de Fusão/metabolismo
Saccharomyces cerevisiae/metabolismo
Homologia de Sequência de Aminoácidos
Frações Subcelulares/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Complementary); 0 (Fungal Proteins); 0 (Lipids); 0 (Oligosaccharides); 0 (Peptides); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Recombinant Fusion Proteins); 147336-22-9 (Green Fluorescent Proteins); 59694-82-5 (dolichyl-diphosphate-di-N-acetylchitobiose); 7006-34-0 (Asparagine); EC 2.4.1.- (N-Acetylglucosaminyltransferases); EC 2.4.1.- (UDP-N-acetylglucosamine transferase); EC 2.4.1.- (UDP-N-acetylglucosamine-peptide beta-N-acetylglucosaminyltransferase)
[Em] Mês de entrada:0601
[Cu] Atualização por classe:051024
[Lr] Data última revisão:
051024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:050816
[St] Status:MEDLINE


  9 / 127 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:12460943
[Au] Autor:Cipollo JF; Trimble RB
[Ad] Endereço:Department of Biomedical Sciences, State University of New York at Albany School of Public Health, Albany, NY 12201, USA.
[Ti] Título:The Saccharomyces cerevisiae alg12delta mutant reveals a role for the middle-arm alpha1,2Man- and upper-arm alpha1,2Manalpha1,6Man- residues of Glc3Man9GlcNAc2-PP-Dol in regulating glycoprotein glycan processing in the endoplasmic reticulum and Golgi apparatus.
[So] Source:Glycobiology;12(11):749-62, 2002 Nov.
[Is] ISSN:0959-6658
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:N-glycosylation in nearly all eukaryotes proceeds in the endoplasmic reticulum (ER) by transfer of the precursor Glc(3)Man(9)GlcNAc(2) from dolichyl pyrophosphate (PP-Dol) to consensus Asn residues in nascent proteins. The Saccharomyces cerevisiae alg (asparagine-linked glycosylation) mutants fail to synthesize oligosaccharide lipid properly, and the alg12 mutant accumulates a Man(7)GlcNAc(2)-PP-Dol intermediate. We show that the Man(7)GlcNAc(2) released from alg12Delta-secreted invertase is Manalpha1,2Manalpha1,2Manalpha1,3(Manalpha1,2Manalpha1,3Manalpha1,6)-Manbeta1,4-GlcNAcbeta1-4GlcNAcalpha/beta, confirming that the Man(7)GlcNAc(2) is the product of the middle-arm terminal alpha1,2-mannoslytransferase encoded by the ALG9 gene. Although the ER glucose addition and trimming events are similar in alg12Delta and wild-type cells, the central-arm alpha1,2-linked Man residue normally removed in the ER by Mns1p persists in the alg12Delta background. This confirms in vivo earlier in vitro experiments showing that the upper-arm Manalpha1,2Manalpha1,6-disaccharide moiety, missing in alg12Delta Man(7)GlcNAc(2), is recognized and required by Mns1p for optimum mannosidase activity. The presence of this Man influences downstream glycan processing by reducing the efficiency of Ochlp, the cis-Golgi alpha1,6-mannosyltransferase responsible for initiating outer-chain mannan synthesis, leading to hypoglycosylation of external invertase and vacuolar protease A.
[Mh] Termos MeSH primário: Retículo Endoplasmático/metabolismo
Glicoproteínas/metabolismo
Complexo de Golgi/metabolismo
Manosiltransferases/metabolismo
Oligossacarídeos de Poli-Isoprenil Fosfato/metabolismo
Polissacarídeos/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Sequência de Carboidratos
Cromatografia por Troca Iônica
Glicoproteínas/química
Glicosilação
Espectroscopia de Ressonância Magnética
Manosiltransferases/química
Manosiltransferases/genética
Dados de Sequência Molecular
Estrutura Molecular
Mutação/genética
Processamento de Proteína Pós-Traducional
Saccharomyces cerevisiae/citologia
Saccharomyces cerevisiae/enzimologia
Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/química
Proteínas de Saccharomyces cerevisiae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
[Nm] Nome de substância:
0 (Glycoproteins); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Polysaccharides); 0 (Saccharomyces cerevisiae Proteins); EC 2.4.1.- (Alg12 protein, S cerevisiae); EC 2.4.1.- (Mannosyltransferases)
[Em] Mês de entrada:0401
[Cu] Atualização por classe:071114
[Lr] Data última revisão:
071114
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:021204
[St] Status:MEDLINE


  10 / 127 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
[PMID]:12056898
[Au] Autor:Hsu ST; Breukink E; de Kruijff B; Kaptein R; Bonvin AM; van Nuland NA
[Ad] Endereço:Department of NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Institute for Biomembranes, Utrecht University, 3584CH Utrecht, The Netherlands.
[Ti] Título:Mapping the targeted membrane pore formation mechanism by solution NMR: the nisin Z and lipid II interaction in SDS micelles.
[So] Source:Biochemistry;41(24):7670-6, 2002 Jun 18.
[Is] ISSN:0006-2960
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Nisin is an example of type-A lantibiotics that contain cyclic lanthionine rings and unusual dehydrated amino acids. Among the numerous pore-forming antimicrobial peptides, type-A lantibiotics form an unique family of post-translationally modified peptides. Via the recognition of cell wall precursor lipid II, nisin has the capacity to form pores against Gram-positive bacteria with an extremely high activity in the nanomolar (nM) range. Here we report a high-resolution NMR spectroscopy study of nisin/lipid II interactions in SDS micelles as a model membrane system in order to elucidate the mechanism of molecular recognition at residue level. The binding to lipid II was studied through (15)N-(1)H HSQC titration, backbone amide proton temperature coefficient analysis, and heteronuclear (15)N[(1)H]-NOE relaxation dynamics experiments. Upon the addition of lipid II, significant changes were monitored in the N-terminal part of nisin. An extremely low amide proton temperature coefficient (Delta delta/Delta T) was found for the amide proton of Ala3 (> -0.1 ppb/K) in the complex form. This suggests tight hydrogen bonding and/or isolation from the bulk solvent for this residue. Large chemical shift perturbations were also observed in the first two rings. In contrast, the C-terminal part of nisin was almost unaffected. This part of the molecule remains flexible and solvent-exposed. On the basis of our results, a multistep pore-forming mechanism is proposed. The N-terminal part of nisin first binds to lipid II, and a subsequent structural rearrangement takes place. The C-terminal part of nisin is possibly responsible for the activation of the pore formation. In light of the emerging antibiotic resistance problems, an understanding of the specific recognition mechanism of nisin with lipid II at the residue specific level may therefore aid in the development of novel antibiotics.
[Mh] Termos MeSH primário: Canais Iônicos/química
Lipídeos de Membrana/química
Micelas
Nisina/análogos & derivados
Nisina/química
Ressonância Magnética Nuclear Biomolecular/métodos
Oligossacarídeos de Poli-Isoprenil Fosfato/química
Uridina Difosfato Ácido N-Acetilmurâmico/análogos & derivados
Uridina Difosfato Ácido N-Acetilmurâmico/química
[Mh] Termos MeSH secundário: Amidas/química
Sequência de Aminoácidos
Antibacterianos/química
Antibacterianos/metabolismo
Sítios de Ligação
Sequência de Carboidratos
Canais Iônicos/metabolismo
Lipídeos de Membrana/metabolismo
Dados de Sequência Molecular
Nisina/metabolismo
Peptidoglicano
Oligossacarídeos de Poli-Isoprenil Fosfato/metabolismo
Conformação Proteica
Prótons
Dodecilsulfato de Sódio
Soluções
Solventes
Temperatura Ambiente
Termodinâmica
Titulometria
Uridina Difosfato Ácido N-Acetilmurâmico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amides); 0 (Anti-Bacterial Agents); 0 (Ion Channels); 0 (Membrane Lipids); 0 (Micelles); 0 (Peptidoglycan); 0 (Polyisoprenyl Phosphate Oligosaccharides); 0 (Protons); 0 (Solutions); 0 (Solvents); 0 (Uridine Diphosphate N-Acetylmuramic Acid); 0 (muramyl-NAc-(pentapeptide)pyrophosphoryl-undecaprenol); 1414-45-5 (Nisin); 31587-66-3 (undecaprenyl diphosphate-(N-acetylglucosaminyl)(1-4)-N-acetylmuramoyl pentapeptide); 368GB5141J (Sodium Dodecyl Sulfate); KOS9259QVA (nisin Z)
[Em] Mês de entrada:0207
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:020612
[St] Status:MEDLINE



página 1 de 13 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde