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[PMID]: 27741561 [Au] Autor: Sioupouli G; Lambrinidis G; Mikros E; Amillis S; Diallinas G [Ad] Endereço: Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, 15784, Greece. [Ti] Título: Cryptic purine transporters in Aspergillus nidulans reveal the role of specific residues in the evolution of specificity in the NCS1 family. [So] Source: Mol Microbiol;103(2):319-332, 2017 Jan. [Is] ISSN: 1365-2958 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: NCS1 proteins are H or Na symporters responsible for the uptake of purines, pyrimidines or related metabolites in bacteria, fungi and some plants. Fungal NCS1 are classified into two evolutionary and structurally distinct subfamilies, known as Fur- and Fcy-like transporters. These subfamilies have expanded and functionally diversified by gene duplications. The Fur subfamily of the model fungus Aspergillus nidulans includes both major and cryptic transporters specific for uracil, 5-fluorouracil, allantoin or/and uric acid. Here we functionally analyse all four A. nidulans Fcy transporters (FcyA, FcyC, FcyD and FcyE) with previously unknown function. Our analysis shows that FcyD is moderate-affinity, low-capacity, highly specific adenine transporter, whereas FcyE contributes to 8-azaguanine uptake. Mutational analysis of FcyD, supported by homology modelling and substrate docking, shows that two variably conserved residues (Leu356 and Ser359) in transmembrane segment 8 (TMS8) are critical for transport kinetics and specificity differences among Fcy transporters, while two conserved residues (Phe167 and Ser171) in TMS3 are also important for function. Importantly, mutation S359N converts FcyD to a promiscuous nucleobase transporter capable of recognizing adenine, xanthine and several nucleobase analogues. Our results reveal the importance of specific residues in the functional evolution of NCS1 transporters. [Mh] Termos MeSH primário: Aspergillus nidulans/genética Proteínas de Transporte de Nucleobases/genética Purinas/metabolismo [Mh] Termos MeSH secundário: Sequência de Aminoácidos Aspergillus nidulans/metabolismo Evolução Biológica Transporte Biológico Sequência Conservada Proteínas Fúngicas/metabolismo Duplicação Gênica Proteínas de Transporte de Nucleobases/química Proteínas de Transporte de Nucleobases/metabolismo Filogenia Estrutura Terciária de Proteína Homologia de Sequência de Aminoácidos Especificidade por Substrato [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Fungal Proteins); 0 (Nucleobase Transport Proteins); 0 (Purines) [Em] Mês de entrada: 1708 [Cu] Atualização por classe: 170811 [Lr] Data última revisão: 170811 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161015 [St] Status: MEDLINE [do] DOI: 10.1111/mmi.13559

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[PMID]: 27720327 [Au] Autor: Lougiakis N; Gavriil ES; Kairis M; Sioupouli G; Lambrinidis G; Benaki D; Krypotou E; Mikros E; Marakos P; Pouli N; Diallinas G [Ad] Endereço: Division of Pharmaceutical Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece. [Ti] Título: Design and synthesis of purine analogues as highly specific ligands for FcyB, a ubiquitous fungal nucleobase transporter. [So] Source: Bioorg Med Chem;24(22):5941-5952, 2016 Nov 15. [Is] ISSN: 1464-3391 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: In the course of our study on fungal purine transporters, a number of new 3-deazapurine analogues have been rationally designed, based on the interaction of purine substrates with the Aspergillus nidulans FcyB carrier, and synthesized following an effective synthetic procedure. Certain derivatives have been found to specifically inhibit FcyB-mediated [ H]-adenine uptake. Molecular simulations have been performed, suggesting that all active compounds interact with FcyB through the formation of hydrogen bonds with Asn163, while the insertion of hydrophobic fragments at position 9 and N6 of 3-deazaadenine enhanced the inhibition. [Mh] Termos MeSH primário: Aspergillus nidulans/química Desenho de Drogas Proteínas de Transporte de Nucleobases/antagonistas & inibidores Purinas/farmacologia [Mh] Termos MeSH secundário: Relação Dose-Resposta a Droga Ligantes Simulação de Acoplamento Molecular Estrutura Molecular Proteínas de Transporte de Nucleobases/metabolismo Purinas/síntese química Purinas/química Relação Estrutura-Atividade [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Ligands); 0 (Nucleobase Transport Proteins); 0 (Purines); W60KTZ3IZY (purine) [Em] Mês de entrada: 1708 [Cu] Atualização por classe: 170919 [Lr] Data última revisão: 170919 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161011 [St] Status: MEDLINE

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[PMID]: 27701112 [Au] Autor: Zürcher E; Liu J; di Donato M; Geisler M; Müller B [Ad] Endereço: Zürich-Basel Plant Science Center, Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland. [Ti] Título: Plant development regulated by cytokinin sinks. [So] Source: Science;353(6303):1027-1030, 2016 09 02. [Is] ISSN: 1095-9203 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Morphogenetic signals control the patterning of multicellular organisms. Cytokinins are mobile signals that are perceived by subsets of plant cells. We found that the responses to cytokinin signaling during Arabidopsis development are constrained by the transporter PURINE PERMEASE 14 (PUP14). In our experiments, the expression of PUP14 was inversely correlated to the cytokinin signaling readout. Loss of PUP14 function allowed ectopic cytokinin signaling accompanied by aberrant morphogenesis in embryos, roots, and the shoot apical meristem. PUP14 protein localized to the plasma membrane and imported bioactive cytokinins, thus depleting apoplastic cytokinin pools and inhibiting perception by plasma membrane-localized cytokinin sensors to create a sink for active ligands. We propose that the spatiotemporal cytokinin sink patterns established by PUP14 determine the cytokinin signaling landscape that shapes the morphogenesis of land plants. [Mh] Termos MeSH primário: Proteínas de Arabidopsis/metabolismo Arabidopsis/crescimento & desenvolvimento Citocininas/metabolismo Proteínas de Transporte de Nucleobases/metabolismo [Mh] Termos MeSH secundário: Arabidopsis/genética Arabidopsis/metabolismo Proteínas de Arabidopsis/genética Membrana Celular/enzimologia Ligantes Meristema/crescimento & desenvolvimento Meristema/metabolismo Proteínas de Transporte de Nucleobases/genética Raízes de Plantas/genética Raízes de Plantas/crescimento & desenvolvimento Raízes de Plantas/metabolismo Brotos de Planta/genética Brotos de Planta/crescimento & desenvolvimento Brotos de Planta/metabolismo Transdução de Sinais [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Arabidopsis Proteins); 0 (Cytokinins); 0 (Ligands); 0 (Nucleobase Transport Proteins); 0 (purine permease 14, Arabidopsis); 37217-36-0 (purine permease) [Em] Mês de entrada: 1703 [Cu] Atualização por classe: 170310 [Lr] Data última revisão: 170310 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161005 [St] Status: MEDLINE

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[PMID]: 26773540 [Au] Autor: Minton JA; Rapp M; Stoffer AJ; Schultes NP; Mourad GS [Ad] Endereço: Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA. [Ti] Título: Heterologous complementation studies reveal the solute transport profiles of a two-member nucleobase cation symporter 1 (NCS1) family in Physcomitrella patens. [So] Source: Plant Physiol Biochem;100:12-7, 2016 Mar. [Is] ISSN: 1873-2690 [Cp] País de publicação: France [La] Idioma: eng [Ab] Resumo: As part of an evolution-function analysis, two nucleobase cation symporter 1 (NCS1) from the moss Physcomitrella patens (PpNCS1A and PpNCS1B) are examined--the first such analysis of nucleobase transporters from early land plants. The solute specificity profiles for the moss NCS1 were determined through heterologous expression, growth and radiolabeled uptake experiments in NCS1-deficient Saccharomyces cerevisiae. Both PpNCS1A and 1B, share the same profiles as high affinity transporters of adenine and transport uracil, guanine, 8-azaguanine, 8-azaadenine, cytosine, 5-fluorocytosine, hypoxanthine, and xanthine. Despite sharing the same solute specificity profile, PpNCS1A and PpNCS1B move nucleobase compounds with different efficiencies. The broad nucleobase transport profile of PpNCS1A and 1B differs from the recently-characterized Viridiplantae NCS1 in breadth, revealing a flexibility in solute interactions with NCS1 across plant evolution. [Mh] Termos MeSH primário: Bryopsida Proteínas de Transporte de Nucleobases Proteínas de Plantas [Mh] Termos MeSH secundário: Bryopsida/genética Bryopsida/metabolismo Teste de Complementação Genética Proteínas de Transporte de Nucleobases/genética Proteínas de Transporte de Nucleobases/metabolismo Proteínas de Plantas/genética Proteínas de Plantas/metabolismo Saccharomyces cerevisiae/genética Saccharomyces cerevisiae/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Nucleobase Transport Proteins); 0 (Plant Proteins) [Em] Mês de entrada: 1611 [Cu] Atualização por classe: 161230 [Lr] Data última revisão: 161230 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160117 [St] Status: MEDLINE

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[PMID]: 26525799 [Au] Autor: Charlier C; El Sissy C; Bachelier-Bassi S; Scemla A; Quesne G; Sitterlé E; Legendre C; Lortholary O; Bougnoux ME [Ad] Endereço: Université Paris Descartes Sorbonne Paris Cité, Service de Maladies Infectieuses et Tropicales, Centre d'Infectiologie Necker-Pasteur, Hôpital Universitaire Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Institut Imagine, Paris, France caroline.charlier@aphp.fr. [Ti] Título: Acquired Flucytosine Resistance during Combination Therapy with Caspofungin and Flucytosine for Candida glabrata Cystitis. [So] Source: Antimicrob Agents Chemother;60(1):662-5, 2015 Nov 02. [Is] ISSN: 1098-6596 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Treatment of Candida glabrata cystitis remains a therapeutic challenge, and an antifungal combination using flucytosine is one option. We describe two patients with refractory C. glabrata cystitis who failed flucytosine combined with caspofungin with early-acquired high-level resistance to flucytosine due to nonsense mutations in the FUR1 gene. Rapidly acquired flucytosine resistance with microbiological failure should discourage combination of caspofungin and flucytosine during urinary candidiasis. [Mh] Termos MeSH primário: Antifúngicos/administração & dosagem Candida glabrata/efeitos dos fármacos Candidíase/tratamento farmacológico Cistite/tratamento farmacológico Farmacorresistência Fúngica/efeitos dos fármacos Equinocandinas/administração & dosagem Flucitosina/administração & dosagem Lipopeptídeos/administração & dosagem [Mh] Termos MeSH secundário: Idoso Sequência de Bases Candida glabrata/genética Candida glabrata/isolamento & purificação Candida glabrata/metabolismo Candidíase/microbiologia Candidíase/patologia Códon sem Sentido Cistite/microbiologia Cistite/patologia Farmacorresistência Fúngica/genética Quimioterapia Combinada Feminino Proteínas Fúngicas/genética Proteínas Fúngicas/metabolismo Expressão Gênica Seres Humanos Masculino Dados de Sequência Molecular Proteínas de Transporte de Nucleobases/genética Proteínas de Transporte de Nucleobases/metabolismo Falha de Tratamento Bexiga Urinária/microbiologia Bexiga Urinária/patologia [Pt] Tipo de publicação: CASE REPORTS; JOURNAL ARTICLE [Nm] Nome de substância: 0 (Antifungal Agents); 0 (Codon, Nonsense); 0 (Echinocandins); 0 (Fungal Proteins); 0 (Lipopeptides); 0 (Nucleobase Transport Proteins); D83282DT06 (Flucytosine); F0XDI6ZL63 (caspofungin) [Em] Mês de entrada: 1609 [Cu] Atualização por classe: 160701 [Lr] Data última revisão: 160701 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 151104 [St] Status: MEDLINE [do] DOI: 10.1128/AAC.02265-15

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[PMID]: 26330332 [Au] Autor: Damaraju VL; Kuzma M; Cass CE; Sawyer MB [Ad] Endereço: Department of Oncology, University of Alberta, Edmonton, AB, Canada. [Ti] Título: Inhibition of sodium-independent and sodium-dependent nucleobase transport activities by tyrosine kinase inhibitors. [So] Source: Cancer Chemother Pharmacol;76(5):1093-8, 2015 Nov. [Is] ISSN: 1432-0843 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: PURPOSE: Effects of tyrosine kinase inhibitors (TKIs) on equilibrative nucleobase transport (ENBT) and sodium-dependent nucleobase transport (SNBT) activities were investigated in normal human renal proximal tubule epithelial cells (hRPTECs) and in pig kidney cell line (LLC-PK1). METHODS: Uptake assays were performed by assessing accumulation of radiolabeled nucleobases over time into hRPTECs or LLC-PK1 cell lines which express ENBT and SNBT activities, respectively. Dose-response curves for inhibition of 1 µM [(3)H]adenine or 1 µM [(3)H]hypoxanthine were examined in hRPTECs and in LLC-PK1 cells with varying TKI concentrations (0-100 µM) to calculate the IC50 values (mean ± S.E) for inhibition. RESULTS: Gefitinib inhibited ENBT activity with an IC50 value of 0.7 µM, thus indicating strong interactions of ENBT with gefitinib in hRPTECs. Erlotinib > sorafenib > imatinib > sunitinib inhibited ENBT with IC50 values of 15, 40, 60, 78 µM, respectively, whereas dasatinib, lapatinib, and vandetanib were not inhibitory at concentrations >100 µM. Similar studies in LLC-PK1 cells which exhibit SNBT activity showed that vandetanib was the most potent inhibitor followed by sorafenib > erlotinib > gefitinib > sunitinib > imatinib with IC50 values of 14, 25, 28, 40, 47, 94 µM, respectively, whereas dasatinib and lapatinib were not inhibitory at concentrations >100 µM. CONCLUSIONS: These results suggest for the first time inhibition of both ENBT and SNBT transport activities by TKIs. These results suggest that it is important to consider potential effects on combination regimens using TKIs with nucleobase drugs such as 5-FU in cancer treatment. [Mh] Termos MeSH primário: Adenina/metabolismo Antineoplásicos/farmacologia Transporte Biológico/efeitos dos fármacos Túbulos Renais Proximais/efeitos dos fármacos Proteínas de Transporte de Nucleobases/antagonistas & inibidores Inibidores de Proteínas Quinases/farmacologia Proteínas Tirosina Quinases/antagonistas & inibidores Sódio/fisiologia [Mh] Termos MeSH secundário: Animais Antineoplásicos/farmacocinética Ligação Competitiva Linhagem Celular Células Epiteliais/efeitos dos fármacos Células Epiteliais/metabolismo Seres Humanos Concentração Inibidora 50 Túbulos Renais Proximais/metabolismo Proteínas de Neoplasias/antagonistas & inibidores Proteínas de Transporte de Nucleobases/classificação Inibidores de Proteínas Quinases/classificação Inibidores de Proteínas Quinases/farmacocinética Sus scrofa Suínos [Pt] Tipo de publicação: COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Antineoplastic Agents); 0 (Neoplasm Proteins); 0 (Nucleobase Transport Proteins); 0 (Protein Kinase Inhibitors); 9NEZ333N27 (Sodium); EC 2.7.10.1 (Protein-Tyrosine Kinases); JAC85A2161 (Adenine) [Em] Mês de entrada: 1601 [Cu] Atualização por classe: 151021 [Lr] Data última revisão: 151021 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150903 [St] Status: MEDLINE [do] DOI: 10.1007/s00280-015-2859-8

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[PMID]: 26192456 [Au] Autor: Karena E; Tatsaki E; Lambrinidis G; Mikros E; Frillingos S [Ad] Endereço: Laboratory of Biological Chemistry, University of Ioannina School of Health Sciences, Ioannina, Greece. [Ti] Título: Analysis of conserved NCS2 motifs in the Escherichia coli xanthine permease XanQ. [So] Source: Mol Microbiol;98(3):502-17, 2015 Oct. [Is] ISSN: 1365-2958 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The xanthine permease XanQ of Escherichia coli is a paradigm for transporters of the evolutionarily broad family nucleobase-cation symporter-2 (NCS2) that transport key metabolites or anti-metabolite analogs. Most functionally known members are xanthine/uric acid transporters related to XanQ and belong to a distinct phylogenetic cluster of the family. Here, we present a comprehensive mutagenesis of XanQ based on the identification and Cys-scanning analysis of conserved sequence motifs in this cluster. Results are interpreted in relation to homology modeling on the structurally known template of UraA and previous data on critical binding-site residues in transmembrane segments (TMs) 3, 8 and 10. The current analysis, of motifs distant to the binding site, revealed a set of functionally important residues in TMs 2, 5, 12 and 13, including seven irreplaceable ones, of which six are Gly residues in the gate domain (159, 369, 370, 383, 409) and in TM2 (Gly-71), and one is polar (Gln-75). Gln-75 (TM2) is probably crucial in a network of hydrogen-bonding interactions in the middle of the core domain involving another essential residue, Asp-304 (TM9). Although the two residues are irreplaceable individually, combinatorial replacement of Gln-75 with Asn and of Asp-304 with Glu rescues significant transport activity. [Mh] Termos MeSH primário: Escherichia coli/enzimologia Proteínas de Transporte de Nucleobases/genética Proteínas de Transporte de Nucleobases/metabolismo Xantina/metabolismo [Mh] Termos MeSH secundário: Motivos de Aminoácidos Sequência de Aminoácidos Sítios de Ligação Transporte Biológico Ativo Sequência Conservada Escherichia coli/genética Proteínas de Escherichia coli/metabolismo Dados de Sequência Molecular Mutagênese Sítio-Dirigida/métodos Mutação Proteínas de Transporte de Nucleobases/química Filogenia Estrutura Secundária de Proteína Relação Estrutura-Atividade Ácido Úrico/metabolismo Xantina/química [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Escherichia coli Proteins); 0 (Nucleobase Transport Proteins); 1AVZ07U9S7 (Xanthine); 268B43MJ25 (Uric Acid) [Em] Mês de entrada: 1608 [Cu] Atualização por classe: 151027 [Lr] Data última revisão: 151027 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150721 [St] Status: MEDLINE [do] DOI: 10.1111/mmi.13138

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[PMID]: 26123924 [Au] Autor: Vanden Heuvel JP; Thompson JT; Albrecht P; Mandetta D; Kamerow H; Ford JP [Ad] Endereço: Department of Veterinary and Biomedical Sciences and Center for Molecular Toxicology and Carcinogenesis, Penn State University, 325 Life Sciences Building, University Park, PA, 16802, USA. [Ti] Título: Differential nucleobase protection against 5-fluorouracil toxicity for squamous and columnar cells: implication for tissue function and oncogenesis. [So] Source: Invest New Drugs;33(5):1003-11, 2015 Oct. [Is] ISSN: 1573-0646 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: PURPOSE: The goal of these studies was to test if local excess of a normal nucleobase substrate prevents the toxicity of protracted 5FU exposure used in human cancer treatment. METHODS: Messenger RNA expression studies were performed of 5FU activating enzymes in human colon cancer cells lines (CaCo-2, HT-29), primary human gingival cells (HEGP), and normal esophageal and gastric clinical tissue samples. Excess nucleobase was then used in vitro to protect cells from 5FU toxicity. RESULTS: Pyrimidine salvage pathways predominate in squamous cells of the gingiva (HEGP) and esophageal tissue. Excess salvage nucleobase uracil but not adenine prevented 5FU toxicity in HEGP cells. Pyrimidine de novo synthesis predominates in columnar Caco-2, HT-29 and gastric tissue. Excess nucleobase adenine but not uracil prevented 5FU toxicity to Caco-2 and HT-29 cells. CONCLUSION: The directed application of the normal nucleobase uracil to the squamous cells of the oral mucosa and palms and soles together with the delivery of the normal nucleobase adenine to the columnar cells of the GI tract may enable the safe delivery of higher 5FU dose intensity. These results also suggest a feature of tissue function where squamous cells grow largely by recycling overlying tissue cell components. Columnar cells use absorbed surface nutrients for de novo growth. A disruption of this tissue function can result in growth derived from an underlying nutrient source. That change would also cause the loss of the region of cell turnover at the tissue surface. Subsequent cell proliferation with limiting nutrient availability could promote oncogenesis in such initiated tissue. [Mh] Termos MeSH primário: Adenina/farmacologia Fluoruracila/toxicidade Substâncias Protetoras/farmacologia Pirimidinas/farmacologia Uracila/farmacologia [Mh] Termos MeSH secundário: Carcinogênese Linhagem Celular Tumoral Replicação do DNA Células Epiteliais/efeitos dos fármacos Esôfago/citologia Mucosa Gástrica/citologia Expressão Gênica/efeitos dos fármacos Seres Humanos Proteínas de Transporte de Nucleobases/efeitos dos fármacos RNA Mensageiro [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Nucleobase Transport Proteins); 0 (Protective Agents); 0 (Pyrimidines); 0 (RNA, Messenger); 56HH86ZVCT (Uracil); JAC85A2161 (Adenine); K8CXK5Q32L (pyrimidine); U3P01618RT (Fluorouracil) [Em] Mês de entrada: 1606 [Cu] Atualização por classe: 160330 [Lr] Data última revisão: 160330 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150701 [St] Status: MEDLINE [do] DOI: 10.1007/s10637-015-0259-x

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[PMID]: 25639910 [Au] Autor: Krypotou E; Scazzocchio C; Diallinas G [Ad] Endereço: Faculty of Biology, University of Athens, Panepistimioupolis, Athens 15784, Greece. [Ti] Título: Functional characterization of NAT/NCS2 proteins of Aspergillus brasiliensis reveals a genuine xanthine-uric acid transporter and an intrinsically misfolded polypeptide. [So] Source: Fungal Genet Biol;75:56-63, 2015 Feb. [Is] ISSN: 1096-0937 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The Nucleobase-Ascorbate Transporter (NAT) family includes members in nearly all domains of life. Functionally characterized NAT transporters from bacteria, fungi, plants and mammals are ion-coupled symporters specific for the uptake of purines, pyrimidines and related analogues. The characterized mammalian NATs are specific for the uptake of L-ascorbic acid. In this work we identify in silico a group of fungal putative transporters, named UapD-like proteins, which represent a novel NAT subfamily. To understand the function and specificity of UapD proteins, we cloned and functionally characterized the two Aspergillus brasiliensis NAT members (named AbUapC and AbUapD) by heterologous expression in Aspergillus nidulans. AbUapC represents canonical NATs (UapC or UapA), while AbUapD represents the new subfamily. AbUapC is a high-affinity, high-capacity, H(+)/xanthine-uric acid transporter, which can also recognize other purines with very low affinity. No apparent transport function could be detected for AbUapD. GFP-tagging showed that, unlike AbUapC which is localized in the plasma membrane, AbUapD is ER-retained and degraded in the vacuoles, a characteristic of misfolded proteins. Chimeric UapA/AbUapD molecules are also turned-over in the vacuole, suggesting that UapD includes intrinsic peptidic sequences leading to misfolding. The possible evolutionary implication of such conserved, but inactive proteins is discussed. [Mh] Termos MeSH primário: Aspergillus/genética Proteínas de Transporte de Nucleobases/metabolismo Ácido Úrico/metabolismo Xantinas/metabolismo [Mh] Termos MeSH secundário: Sequência de Aminoácidos Aspergillus nidulans/genética Aspergillus nidulans/metabolismo Transporte Biológico Simulação por Computador Proteínas Fúngicas/química Proteínas Fúngicas/genética Proteínas Fúngicas/metabolismo Dados de Sequência Molecular Proteínas de Transporte de Nucleobases/química Proteínas de Transporte de Nucleobases/genética Peptídeos/química Filogenia Dobramento de Proteína Proteínas Recombinantes de Fusão/síntese química Proteínas Recombinantes de Fusão/metabolismo Alinhamento de Sequência [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Fungal Proteins); 0 (Nucleobase Transport Proteins); 0 (Peptides); 0 (Recombinant Fusion Proteins); 0 (Xanthines); 268B43MJ25 (Uric Acid) [Em] Mês de entrada: 1508 [Cu] Atualização por classe: 150302 [Lr] Data última revisão: 150302 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150203 [St] Status: MEDLINE

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[PMID]: 24947336 [Au] Autor: Kato K; Shitan N; Shoji T; Hashimoto T [Ad] Endereço: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama 8916-5, Ikoma, Nara 630-0192, Japan. [Ti] Título: Tobacco NUP1 transports both tobacco alkaloids and vitamin B6. [So] Source: Phytochemistry;113:33-40, 2015 May. [Is] ISSN: 1873-3700 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The purine permeases (PUPs) constitute a large plasma membrane-localized transporter family in plants that mediates the proton-coupled uptake of nucleotide bases and their derivatives, such as adenine, cytokinins, and caffeine. A Nicotiana tabacum (tobacco) PUP-family transporter, nicotine uptake permease 1 (NtNUP1), was previously shown to transport tobacco alkaloids and to affect both nicotine biosynthesis and root growth in tobacco plants. Since Arabidopsis PUP1, which belongs to the same subclade as NtNUP1, was recently reported to transport pyridoxine and its derivatives (vitamin B6), it was of interest to examine whether NtNUP1 could also transport these substrates. Direct uptake measurements in the yeast Saccharomyces cerevisiae demonstrated that NtNUP1 efficiently promoted the uptake of pyridoxamine, pyridoxine, anatabine, and nicotine. The naturally occurring (S)-isomer of nicotine was preferentially transported over the (R)-isomer. Transport studies using tobacco BY-2 cell lines overexpressing NtNUP1 or PUP1 showed that NtNUP1, similar to PUP1, transported various compounds containing a pyridine ring, but that the two transporters had distinct substrate preferences. Therefore, the previously reported effects of NtNUP1 on tobacco physiology might involve bioactive metabolites other than tobacco alkaloids. [Mh] Termos MeSH primário: Alcaloides/metabolismo Proteínas de Transporte de Nucleobases/metabolismo Piridinas/metabolismo Tabaco/metabolismo Vitamina B 6/metabolismo [Mh] Termos MeSH secundário: Proteínas de Plantas/metabolismo Raízes de Plantas/metabolismo Piridoxamina/metabolismo Piridoxina/metabolismo Saccharomyces cerevisiae/genética Tabaco/química [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Alkaloids); 0 (Nucleobase Transport Proteins); 0 (Plant Proteins); 0 (Pyridines); 37217-36-0 (purine permease); 5PP654XB7D (anatabine); 6466NM3W93 (Pyridoxamine); 8059-24-3 (Vitamin B 6); KV2JZ1BI6Z (Pyridoxine); NH9L3PP67S (pyridine) [Em] Mês de entrada: 1601 [Cu] Atualização por classe: 150521 [Lr] Data última revisão: 150521 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 140621 [St] Status: MEDLINE

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