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1.
PLoS Genet ; 19(4): e1010732, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37115757

RESUMEN

Overexpression can help life adapt to stressful environments, making an examination of overexpressed genes valuable for understanding stress tolerance mechanisms. However, a systematic study of genes whose overexpression is functionally adaptive (GOFAs) under stress has yet to be conducted. We developed a new overexpression profiling method and systematically identified GOFAs in Saccharomyces cerevisiae under stress (heat, salt, and oxidative). Our results show that adaptive overexpression compensates for deficiencies and increases fitness under stress, like calcium under salt stress. We also investigated the impact of different genetic backgrounds on GOFAs, which varied among three S. cerevisiae strains reflecting differing calcium and potassium requirements for salt stress tolerance. Our study of a knockout collection also suggested that calcium prevents mitochondrial outbursts under salt stress. Mitochondria-enhancing GOFAs were only adaptive when adequate calcium was available and non-adaptive when calcium was deficient, supporting this idea. Our findings indicate that adaptive overexpression meets the cell's needs for maximizing the organism's adaptive capacity in the given environment and genetic context.


Asunto(s)
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Calcio , Proteínas de Saccharomyces cerevisiae/genética , Mitocondrias/genética , Antecedentes Genéticos
2.
Biosci Biotechnol Biochem ; 86(6): 763-769, 2022 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-35289847

RESUMEN

Accumulation levels of Arg, Lys, and His in vacuoles of Schizosaccharomyces pombe cells were drastically decreased by the disruption of SPAC24H6.11c (vsb1+) gene identified by a homology search with the VSB1 gene of Saccharomyces cerevisiae. The Vsb1p fused with green fluorescent protein particularly localized at vacuolar membranes in S. pombe cells. Overexpression of vsb1+ markedly increased vacuolar levels of basic amino acids; however, overexpression of the vsb1D174A mutant did not affect the levels of these amino acids. These results suggest that the vsb1+ contributes to the accumulation of basic amino acids into the vacuoles of S. pombe, and the aspartate residue in the putative first transmembrane domain conserved among fungal homologs is crucial for the function of Vsb1p.


Asunto(s)
Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Aminoácidos Básicos/genética , Aminoácidos Básicos/metabolismo , Proteínas de la Membrana/genética , Saccharomyces cerevisiae/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Vacuolas/metabolismo
3.
Biosci Biotechnol Biochem ; 85(3): 587-599, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33624780

RESUMEN

In Saccharomyces cerevisiae, Avt4 exports neutral and basic amino acids from vacuoles. Previous studies have suggested that the GATA transcription factors, Gln3 and Gat1, which are key regulators that adapt cells in response to changes in amino acid status, are involved in the AVT4 transcription. Here, we show that mutations in the putative GATA-binding sites of the AVT4 promoter reduced AVT4 expression. Consistently, a chromatin immunoprecipitation (ChIP) assay revealed that Gat1-Myc13 binds to the AVT4 promoter. Previous microarray results were confirmed that gln3∆gat1∆ cells showed a decrease in expression of AVT1 and AVT7, which also encode vacuolar amino acid transporters. Additionally, ChIP analysis revealed that the AVT6 encoding vacuolar acidic amino acid exporter represents a new direct target of the GATA transcription factor. The broad effect of the GATA transcription factors on the expression of AVT transporters suggests that vacuolar amino acid transport is integrated into cellular amino acid homeostasis.


Asunto(s)
Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Factores de Transcripción GATA/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Vacuolas/metabolismo , Sistemas de Transporte de Aminoácidos Básicos/genética , Sistemas de Transporte de Aminoácidos Neutros/genética , Sitios de Unión , Homeostasis , Regiones Promotoras Genéticas , Proteínas de Saccharomyces cerevisiae/genética
4.
Biosci Biotechnol Biochem ; 85(5): 1157-1164, 2021 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-33704406

RESUMEN

The Ygr125w was previously identified as a vacuolar membrane protein by a proteomic analysis. We found that vacuolar levels of basic amino acids drastically decreased in ygr125wΔ cells. Since N- or C-terminally tagged Ygr125w was not functional, an expression plasmid of YGR125w with HA3-tag inserted in its N-terminal hydrophilic region was constructed. Introduction of this plasmid into ygr125w∆ cells restored the vacuolar levels of basic amino acids. We successfully detected the uptake activity of arginine by the vacuolar membrane vesicles depending on HA3-YGR125w expression. A conserved aspartate residue in the predicted first transmembrane helix (D223) was indispensable for the accumulation of basic amino acids. YGR125w has been recently reported as a gene involved in vacuolar storage of arginine; and it is designated as VSB1. Taken together, our findings indicate that Ygr125w/Vsb1 contributes to the uptake of arginine into vacuoles and vacuolar compartmentalization of basic amino acids.


Asunto(s)
Aminoácidos Básicos/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Vacuolas/metabolismo , Arginina/metabolismo , Ácido Aspártico/química , Ácido Aspártico/metabolismo , Transporte Biológico , Clonación Molecular , Colorantes Fluorescentes/química , Expresión Génica , Prueba de Complementación Genética , Hemaglutininas Virales/genética , Hemaglutininas Virales/metabolismo , Membranas Intracelulares/metabolismo , Proteínas de Transporte de Membrana/genética , Plásmidos/química , Plásmidos/metabolismo , Compuestos de Piridinio/química , Compuestos de Amonio Cuaternario/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
5.
Biol Pharm Bull ; 41(10): 1496-1501, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30270317

RESUMEN

In yeast cells growing under nutrient-rich condition approximately 50% of total amino acids are accumulated in the vacuoles; however, the composition of amino acids in the cytosol and in the vacuoles is quite different. The vacuoles, like lysosomes, degrade proteins transported into their lumen and produce amino acids. These amino acids should be quickly excreted to the cytosol under nutrient starvation condition and recycled for de novo protein synthesis. These suggest that specific machineries that transport amino acids into and out of the vacuoles operate at the vacuolar membrane. Several families of transporter involved in the vacuolar compartmentalization of amino acids have been identified and characterized using budding yeast Saccharomyces cerevisiae. In this review, we describe the vacuolar amino acid transporters identified so far and introduce recent findings on their activity and physiological function.


Asunto(s)
Aminoácidos/metabolismo , Membranas Intracelulares/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiología , Vacuolas/metabolismo , Transporte Biológico , Medios de Cultivo , Citosol/metabolismo , Lisosomas/metabolismo , Nutrientes , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo
6.
Biosci Biotechnol Biochem ; 80(6): 1125-30, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26928127

RESUMEN

The vacuolar membrane proteins Ypq1p, Ypq2p, and Ypq3p of Saccharomyces cerevisiae are known as the members of the PQ-loop protein family. We found that the ATP-dependent uptake activities of arginine and histidine by the vacuolar membrane vesicles were decreased by ypq2Δ and ypq3Δ mutations, respectively. YPQ1 and AVT1, which are involved in the vacuolar uptake of lysine/arginine and histidine, respectively, were deleted in addition to ypq2Δ and ypq3Δ. The vacuolar membrane vesicles isolated from the resulting quadruple deletion mutant ypq1Δypq2Δypq3Δavt1Δ completely lost the uptake activity of basic amino acids, and that of histidine, but not lysine and arginine, was evidently enhanced by overexpressing YPQ3 in the mutant. These results suggest that Ypq3p is specifically involved in the vacuolar uptake of histidine in S. cerevisiae. The cellular level of Ypq3p-HA(3) was enhanced by depletion of histidine from culture medium, suggesting that it is regulated by the substrate.


Asunto(s)
Sistemas de Transporte de Aminoácidos/genética , Antiportadores/genética , Vesículas Citoplasmáticas/metabolismo , Regulación Fúngica de la Expresión Génica , Histidina/metabolismo , Proteínas de la Membrana/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Adenosina Trifosfato/metabolismo , Sistemas de Transporte de Aminoácidos/deficiencia , Antiportadores/deficiencia , Arginina/metabolismo , Transporte Biológico , Membrana Celular/metabolismo , Eliminación de Gen , Lisina/metabolismo , Proteínas de la Membrana/deficiencia , Isoformas de Proteínas/deficiencia , Isoformas de Proteínas/genética , Saccharomyces cerevisiae/metabolismo , Vacuolas/metabolismo
7.
Biosci Biotechnol Biochem ; 80(12): 2291-2297, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27555098

RESUMEN

Avt3p, a vacuolar amino acid exporter (656 amino acid residues) that is important for vacuolar amino acid compartmentalization as well as spore formation in Schizosaccharomyces pombe, has an extremely long hydrophilic region (approximately 290 amino acid residues) at its N-terminus. Because known functional domains have not been found in this region, its functional role was examined with a deletion mutant avt3(∆1-270) expressed in S. pombe avt3∆ cells. The deletion of this region did not affect its intracellular localization or vacuolar contents of basic amino acids as well as neutral ones. The defect of avt3Δ cells in spore formation was rescued by the expression of avt3+ but was not completely rescued by the expression of avt3(∆1-270). The N-terminal region is thus dispensable for the function of Avt3p as an amino acid exporter, but it is likely to be involved in the role of Avt3p under nutritional starvation conditions.


Asunto(s)
Aminoácidos/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/citología , Schizosaccharomyces/metabolismo , Vacuolas/metabolismo , Transporte de Proteínas , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Eliminación de Secuencia , Esporas Fúngicas/metabolismo
8.
Biosci Biotechnol Biochem ; 80(2): 279-87, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26325352

RESUMEN

In the vacuolar basic amino acid (VBA) transporter family of Saccharomyces cerevisiae, VBA4 encodes a vacuolar membrane protein with 14 putative transmembrane helices. Transport experiments with isolated vacuolar membrane vesicles and estimation of the amino acid contents in vacuoles showed that Vba4p is not likely involved in the transport of amino acids. We found that the vba4Δ cells, as well as vba1Δ and vba2Δ cells, showed increased susceptibility to several drugs, particularly to azoles. Although disruption of the VBA4 gene did not affect the salt tolerance of the cells, vacuolar fragmentation observed under high salt conditions was less prominent in vba4Δ cells than in wild type, vba1Δ, and vba2Δ cells. Vba4p differs from Vba1p and Vba2p as a vacuolar transporter but is important for the drug resistance and vacuolar morphology of S. cerevisiae.


Asunto(s)
Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Antifúngicos/farmacología , Farmacorresistencia Fúngica/genética , Membranas Intracelulares/metabolismo , Saccharomyces cerevisiae/metabolismo , Vacuolas/metabolismo , Sistemas de Transporte de Aminoácidos Básicos/genética , Aminoácidos/metabolismo , Transporte Biológico , Fluconazol/farmacología , Expresión Génica , Membranas Intracelulares/efectos de los fármacos , Membranas Intracelulares/ultraestructura , Cetoconazol/farmacología , Miconazol/farmacología , Forma de los Orgánulos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/ultraestructura , Tolerancia a la Sal , Cloruro de Sodio/farmacología , Vacuolas/efectos de los fármacos , Vacuolas/ultraestructura
9.
Biosci Biotechnol Biochem ; 79(12): 1972-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26083447

RESUMEN

Fusarium oxysporum causes wilt disease in many plant families, and many genes are involved in its development or growth in host plants. A recent study revealed that vacuolar amino acid transporters play an important role in spore formation in Schizosaccharomyces pombe and Saccharomyces cerevisiae. To investigate the role of vacuolar amino acid transporters of this phytopathogenic fungus, the FOXG_11334 (FoAVT3) gene from F. oxysporum was isolated and its function was characterized. Transcription of FoAVT3 was upregulated after rapamycin treatment. A green fluorescent protein fusion of FoAvt3p was localized to vacuolar membranes in both S. cerevisiae and F. oxysporum. Analysis of the amino acid content of the vacuolar fraction and amino acid transport activities using vacuolar membrane vesicles from S. cerevisiae cells heterologously expressing FoAVT3 revealed that FoAvt3p functions as a vacuolar amino acid transporter, exporting neutral amino acids. We conclude that the FoAVT3 gene encodes a vacuolar neutral amino acid transporter.


Asunto(s)
Sistemas de Transporte de Aminoácidos/metabolismo , Proteínas Fúngicas/metabolismo , Fusarium/citología , Fusarium/genética , Saccharomyces cerevisiae/genética , Vacuolas/metabolismo , Secuencia de Aminoácidos , Sistemas de Transporte de Aminoácidos/química , Sistemas de Transporte de Aminoácidos/genética , Aminoácidos/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Genoma Fúngico/genética , Datos de Secuencia Molecular , Transporte de Proteínas , Saccharomyces cerevisiae/metabolismo , Alineación de Secuencia
10.
Biosci Biotechnol Biochem ; 79(2): 190-5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25266154

RESUMEN

Active transport systems for various amino acids operate in the vacuolar membrane of Saccharomyces cerevisiae. The gene families for vacuolar amino acid transporters were identified by reverse genetics experiments. In the AVT transporter family, Avt1p works for active uptake of amino acid into vacuole, and Avt3p, Avt4p, and Avt6p for active extrusion of amino acid from vacuole to cytosol. Here, we found green fluorescent protein-tagged Avt7p, an unidentified member of the AVT family, localized to the vacuolar membrane of S. cerevisiae. Disruption of the AVT7 gene enhanced both vacuolar contents of several amino acids and uptake activities of glutamine and proline by vacuolar membrane vesicles. Efficiency of spore formation was impaired by the disruption of the AVT7 gene, suggesting the physiological importance of Avt7p-dependent efflux of amino acid from vacuoles under nutrient-poor condition.


Asunto(s)
Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Aminoácidos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/metabolismo , Esporas Fúngicas/fisiología , Membranas Intracelulares/metabolismo , Nitrógeno/deficiencia , Transporte de Proteínas , Saccharomyces cerevisiae/fisiología , Vacuolas/metabolismo
11.
Biosci Biotechnol Biochem ; 79(5): 782-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25747199

RESUMEN

Several genes for vacuolar amino acid transport were reported in Saccharomyces cerevisiae, but have not well been investigated. We characterized AVT1, a member of the AVT vacuolar transporter family, which is reported to be involved in lifespan of yeast. ATP-dependent uptake of isoleucine and histidine by the vacuolar vesicles of an AVT exporter mutant was lost by introducing avt1∆ mutation. Uptake activity was inhibited by the V-ATPase inhibitor: concanamycin A and a protonophore. Isoleucine uptake was inhibited by various neutral amino acids and histidine, but not by γ-aminobutyric acid, glutamate, and aspartate. V-ATPase-dependent acidification of the vesicles was declined by the addition of isoleucine or histidine, depending upon Avt1p. Taken together with the data of the amino acid contents of vacuolar fractions in cells, the results suggested that Avt1p is a proton/amino acid antiporter important for vacuolar compartmentalization of various amino acids.


Asunto(s)
Sistemas de Transporte de Aminoácidos/metabolismo , Aminoácidos Neutros/metabolismo , Antiportadores/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Vacuolas/metabolismo , Sistemas de Transporte de Aminoácidos/genética , Antiportadores/genética , Ácido Aspártico/metabolismo , Transporte Biológico , Ácido Glutámico/metabolismo , Histidina/metabolismo , Membranas Intracelulares/metabolismo , Isoleucina/metabolismo , Protones , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Ácido gamma-Aminobutírico/metabolismo
12.
Biosci Biotechnol Biochem ; 78(7): 1199-202, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25229858

RESUMEN

Saccharomyces cerevisiae Ypq1p is a vacuolar membrane protein of the PQ-loop protein family. We found that ATP-dependent uptake activities of amino acids by vacuolar membrane vesicles were impaired by ypq1∆ mutation. Loss of lysine uptake was most remarkable, and the uptake was recovered by overproduction of Ypq1p. Ypq1p is thus involved in transport of amino acids into vacuoles.


Asunto(s)
Adenosina Trifosfato/metabolismo , Membranas Intracelulares/metabolismo , Lisina/metabolismo , Proteínas de la Membrana/metabolismo , Mutación , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Vacuolas/metabolismo , Transporte Biológico/genética , Proteínas de la Membrana/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
13.
Biosci Biotechnol Biochem ; 78(6): 969-75, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25036121

RESUMEN

Basic amino acids (lysine, histidine and arginine) accumulated in Saccharomyces cerevisiae vacuoles should be mobilized to cytosolic nitrogen metabolism under starvation. We found that the decrease of vacuolar basic amino acids in response to nitrogen starvation was impaired by the deletion of AVT4 gene encoding a vacuolar transporter. In addition, overexpression of AVT4 reduced the accumulation of basic amino acids in vacuoles under nutrient-rich condition. In contrast to AVT4, the deletion and overexpression of AVT3, which encodes the closest homologue of Avt4p, did not affect the contents of vacuolar basic amino acids. Consistent with these, arginine uptake into vacuolar membrane vesicles was decreased by Avt4p-, but not by Avt3p-overproduction, whereas various neutral amino acids were excreted from vacuolar membrane vesicles in a manner dependent on either Avt4p or Avt3p. These results suggest that Avt4p is a vacuolar amino acid exporter involving in the recycling of basic amino acids.


Asunto(s)
Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Aminoácidos Básicos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/metabolismo , Vacuolas/metabolismo , Adenosina Trifosfato/metabolismo , Secuencia de Aminoácidos , Sistemas de Transporte de Aminoácidos Básicos/química , Transporte Biológico , Membranas Intracelulares/metabolismo , Datos de Secuencia Molecular , Proteínas de Saccharomyces cerevisiae/química
14.
Biosci Biotechnol Biochem ; 77(9): 1988-90, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24018691

RESUMEN

A vacuolar membrane protein, Vba2p of Schizosaccharomyces pombe, is involved in basic amino acid uptake by intact cells. Here we found evidence that Vba2p mediated ATP-dependent lysine uptake by vacuolar membrane vesicles of Saccharomyces cerevisiae. Vba2p was also responsible for quinidine sensitivity, and the addition of lysine improved cell growth on quinidine-containing media. These findings should be useful for further characterization of Vba2p.


Asunto(s)
Sistemas de Transporte de Aminoácidos Básicos/genética , Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Membranas Intracelulares/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/genética , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Vacuolas/genética , Adenosina Trifosfato/metabolismo , Expresión Génica , Lisina/metabolismo
15.
Biosci Biotechnol Biochem ; 76(9): 1802-4, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22972345

RESUMEN

Amino acid analysis of Saccharomyces cerevisiae cells indicated that neutral amino acids such as glycine and alanine were probably excluded from the vacuoles, and that vacuolar H(+)-ATPase (V-ATPase) was involved in the vacuolar compartmentalization of these amino acids. We found that vacuolar membrane vesicles export neutral amino acids in an ATP-dependent manner. This is important in identifying vacuolar transporters for neutral amino acids.


Asunto(s)
Adenosina Trifosfato/metabolismo , Aminoácidos Neutros/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Vesículas Transportadoras/metabolismo , ATPasas de Translocación de Protón Vacuolares/metabolismo , Transporte Biológico , Membranas Intracelulares/química , Cinética , Vesículas Transportadoras/química , Vacuolas/química
16.
Biosci Biotechnol Biochem ; 76(10): 1993-5, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23047103

RESUMEN

Vba5p is closest to Vba3p in the vacuolar transporter for basic amino acids (VBA) family of Saccharomyces cerevisiae. We found that green fluorescence protein (GFP)-tagged Vba5p localized exclusively to the plasma membrane. The uptake of lysine and arginine by whole cells was little affected by deletion of the VBA5 gene, but was stimulated by overexpression of the VBA5 gene. The inhibitory effect of 4-nitroquinoline N-oxide on cell growth was accelerated by expression of the VBA5 gene, and was lessened by the addition of arginine. These results suggest that Vba5p is a plasma membrane protein involved in amino acid uptake and drug sensitivity.


Asunto(s)
Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Aminoácidos/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/metabolismo , 4-Nitroquinolina-1-Óxido/farmacología , Secuencia de Aminoácidos , Sistemas de Transporte de Aminoácidos Básicos/química , Transporte Biológico/efectos de los fármacos , Proteínas de la Membrana/química , Datos de Secuencia Molecular , Saccharomyces cerevisiae/citología , Proteínas de Saccharomyces cerevisiae/química
17.
Biosci Biotechnol Biochem ; 75(2): 385-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21307582

RESUMEN

The fission yeast Schizosaccharomyces pombe has a homolog of the budding yeast Atg22p, which is involved in spore formation (Mukaiyama H. et al., Microbiology, 155, 3816-3826 (2009)). GFP-tagged Atg22p in the fission yeast was localized to the vacuolar membrane. Upon disruption of atg22, the amino acid levels of the cellular fraction as well as the vacuolar fraction decreased. The uptake of several amino acids, such as lysine, histidine, and arginine, was impaired in atg22Δ cells. S. pombe Atg22p plays an important role in the compartmentalization of amino acids.


Asunto(s)
Aminoácidos/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/citología , Schizosaccharomyces/metabolismo , Vacuolas/metabolismo , Proteínas Relacionadas con la Autofagia , Transporte Biológico
18.
Biochim Biophys Acta Biomembr ; 1863(2): 183507, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33189720

RESUMEN

The stm1+ (SPAC17C9.10) gene of Schizosaccharomyces pombe is closely related to genes encoding vacuolar PQ-loop proteins, Ypq1, Ypq2, and Ypq3, of Saccharomyces cerevisiae. When stm1+ fused with GFP was expressed in fission or budding yeast, Stm1-GFP localized at the vacuolar membrane. Isolated vacuolar membrane vesicles from S. cerevisiae cells overexpressing stm1+ exhibited stm1+-dependent arginine and lysine uptake activity. Exchange activity of arginine and histidine/arginine, as observed for Ypq2 of S. cerevisiae, was also detected in the vesicles expressing stm1+. The expression levels of stm1+ in S. pombe cells significantly affected the vacuolar contents of lysine, histidine, and arginine. These results suggest that Stm1 is a vacuolar PQ-loop protein involved in the transport of basic amino acids across the vacuolar membrane.


Asunto(s)
Arginina/metabolismo , Membranas Intracelulares/metabolismo , Lisina/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Vacuolas/metabolismo , Arginina/genética , Transporte Biológico Activo/fisiología , Prueba de Complementación Genética , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Lisina/genética , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Vacuolas/genética
19.
Genes Cells ; 14(5): 525-38, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19371383

RESUMEN

Autophagy is a degradation system of cytoplasmic proteins and organelles via formation of double-membrane vesicles called autophagosomes. In the yeast Saccharomyces cerevisiae, autophagosomes are formed via the pre-autophagosomal structure (PAS) in a manner dependent on Atg proteins. Under nutrient-rich condition, Atg9 is recruited to the PAS by binding to Atg11 for the Cvt pathway. However, because Atg9 is recruited to the PAS in atg11Delta cells in starved condition and autophagy is induced, autophagy-specific mechanism for the Atg9 recruitment to the PAS has been assumed. Here, we demonstrate that, in autophagy-inducing condition, Atg9 is recruited to the PAS in a manner dependent on Atg17. Atg9 physically interacts with Atg17 in the presence of rapamycin. This interaction requires Atg1, a protein kinase essential for autophagy. Consistently, the Atg17-dependent PAS localization of Atg9 requires Atg1. However, its kinase activity is dispensable for this process. It rather regulates the equilibrium of assembly and disassembly of Atg9 at the PAS.


Asunto(s)
Autofagia/fisiología , Proteínas Portadoras/metabolismo , Proteínas de la Membrana/metabolismo , Fagosomas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/metabolismo , Autofagia/efectos de los fármacos , Proteínas Relacionadas con la Autofagia , Proteínas Portadoras/efectos de los fármacos , Proteínas de la Membrana/efectos de los fármacos , Fagosomas/efectos de los fármacos , Unión Proteica , Proteínas Quinasas/metabolismo , Transporte de Proteínas/fisiología , Saccharomyces cerevisiae/efectos de los fármacos , Proteínas de Saccharomyces cerevisiae/efectos de los fármacos , Sirolimus/farmacología
20.
Biosci Biotechnol Biochem ; 74(8): 1719-21, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20699567

RESUMEN

The fission yeast Schizosaccharomyces pombe was sensitive to salinity; cell growth was stopped by 0.5 M NaCl and by 10 mM LiCl. The avt5+ gene encodes a vacuolar transporter with a broad specificity for amino acids. We found that the avt5Delta mutant became highly tolerant of Li+ and Na+ in growth. Concanamycin A-sensitive Li+ uptake as well as cellular Li+ content was lower in the avt5 mutant, suggesting a role of Avt5p in cellular uptake of toxic Li+.


Asunto(s)
Litio/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Transporte Biológico , Compartimento Celular , Espacio Intracelular/metabolismo , Schizosaccharomyces/citología
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