Base de dados : MEDLINE
Pesquisa : D13.444.735.130 [Categoria DeCS]
Referências encontradas : 73 [refinar]
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[PMID]:28278262
[Au] Autor:Cuvelier ML; Guo J; Ortiz AC; van Baren MJ; Tariq MA; Partensky F; Worden AZ
[Ad] Endereço:Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, CA, United States of America.
[Ti] Título:Responses of the picoprasinophyte Micromonas commoda to light and ultraviolet stress.
[So] Source:PLoS One;12(3):e0172135, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Micromonas is a unicellular marine green alga that thrives from tropical to polar ecosystems. We investigated the growth and cellular characteristics of acclimated mid-exponential phase Micromonas commoda RCC299 over multiple light levels and over the diel cycle (14:10 hour light:dark). We also exposed the light:dark acclimated M. commoda to experimental shifts from moderate to high light (HL), and to HL plus ultraviolet radiation (HL+UV), 4.5 hours into the light period. Cellular responses of this prasinophyte were quantified by flow cytometry and changes in gene expression by qPCR and RNA-seq. While proxies for chlorophyll a content and cell size exhibited similar diel variations in HL and controls, with progressive increases during day and decreases at night, both parameters sharply decreased after the HL+UV shift. Two distinct transcriptional responses were observed among chloroplast genes in the light shift experiments: i) expression of transcription and translation-related genes decreased over the time course, and this transition occurred earlier in treatments than controls; ii) expression of several photosystem I and II genes increased in HL relative to controls, as did the growth rate within the same diel period. However, expression of these genes decreased in HL+UV, likely as a photoprotective mechanism. RNA-seq also revealed two genes in the chloroplast genome, ycf2-like and ycf1-like, that had not previously been reported. The latter encodes the second largest chloroplast protein in Micromonas and has weak homology to plant Ycf1, an essential component of the plant protein translocon. Analysis of several nuclear genes showed that the expression of LHCSR2, which is involved in non-photochemical quenching, and five light-harvesting-like genes, increased 30 to >50-fold in HL+UV, but was largely unchanged in HL and controls. Under HL alone, a gene encoding a novel nitrite reductase fusion protein (NIRFU) increased, possibly reflecting enhanced N-assimilation under the 625 µmol photons m-2 s-1 supplied in the HL treatment. NIRFU's domain structure suggests it may have more efficient electron transfer than plant NIR proteins. Our analyses indicate that Micromonas can readily respond to abrupt environmental changes, such that strong photoinhibition was provoked by combined exposure to HL and UV, but a ca. 6-fold increase in light was stimulatory.
[Mh] Termos MeSH primário: Proteínas de Algas/genética
Clorófitas/genética
Regulação da Expressão Gênica de Plantas/efeitos da radiação
Luz
Raios Ultravioleta
[Mh] Termos MeSH secundário: Clorófitas/efeitos da radiação
Sequenciamento de Nucleotídeos em Larga Escala
RNA de Algas/genética
Análise de Sequência de RNA
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Algal Proteins); 0 (RNA, Algal)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170310
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0172135


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[PMID]:27451454
[Au] Autor:Bradley IM; Pinto AJ; Guest JS
[Ad] Endereço:Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
[Ti] Título:Design and Evaluation of Illumina MiSeq-Compatible, 18S rRNA Gene-Specific Primers for Improved Characterization of Mixed Phototrophic Communities.
[So] Source:Appl Environ Microbiol;82(19):5878-91, 2016 Oct 01.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:UNLABELLED: The use of high-throughput sequencing technologies with the 16S rRNA gene for characterization of bacterial and archaeal communities has become routine. However, the adoption of sequencing methods for eukaryotes has been slow, despite their significance to natural and engineered systems. There are large variations among the target genes used for amplicon sequencing, and for the 18S rRNA gene, there is no consensus on which hypervariable region provides the most suitable representation of diversity. Additionally, it is unclear how much PCR/sequencing bias affects the depiction of community structure using current primers. The present study amplified the V4 and V8-V9 regions from seven microalgal mock communities as well as eukaryotic communities from freshwater, coastal, and wastewater samples to examine the effect of PCR/sequencing bias on community structure and membership. We found that degeneracies on the 3' end of the current V4-specific primers impact read length and mean relative abundance. Furthermore, the PCR/sequencing error is markedly higher for GC-rich members than for communities with balanced GC content. Importantly, the V4 region failed to reliably capture 2 of the 12 mock community members, and the V8-V9 hypervariable region more accurately represents mean relative abundance and alpha and beta diversity. Overall, the V4 and V8-V9 regions show similar community representations over freshwater, coastal, and wastewater environments, but specific samples show markedly different communities. These results indicate that multiple primer sets may be advantageous for gaining a more complete understanding of community structure and highlight the importance of including mock communities composed of species of interest. IMPORTANCE: The quantification of error associated with community representation by amplicon sequencing is a critical challenge that is often ignored. When target genes are amplified using currently available primers, differential amplification efficiencies result in inaccurate estimates of community structure. The extent to which amplification bias affects community representation and the accuracy with which different gene targets represent community structure are not known. As a result, there is no consensus on which region provides the most suitable representation of diversity for eukaryotes. This study determined the accuracy with which commonly used 18S rRNA gene primer sets represent community structure and identified particular biases related to PCR amplification and Illumina MiSeq sequencing in order to more accurately study eukaryotic microbial communities.
[Mh] Termos MeSH primário: Biota
Primers do DNA/análise
Monitoramento Ambiental/métodos
Microalgas/classificação
Reação em Cadeia da Polimerase/normas
RNA Ribossômico 18S/genética
[Mh] Termos MeSH secundário: Primers do DNA/genética
Água Doce
Microalgas/genética
RNA de Algas/genética
Água do Mar
Águas Residuais
[Pt] Tipo de publicação:EVALUATION STUDIES; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA Primers); 0 (RNA, Algal); 0 (RNA, Ribosomal, 18S); 0 (Waste Water)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171106
[Lr] Data última revisão:
171106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160725
[St] Status:MEDLINE
[do] DOI:10.1128/AEM.01630-16


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[PMID]:27434306
[Au] Autor:Waltman PH; Guo J; Reistetter EN; Purvine S; Ansong CK; van Baren MJ; Wong CH; Wei CL; Smith RD; Callister SJ; Stuart JM; Worden AZ
[Ad] Endereço:University of California at Santa Cruz, Baskin School of Engineering, Santa Cruz, California, 95064, United States of America.
[Ti] Título:Identifying Aspects of the Post-Transcriptional Program Governing the Proteome of the Green Alga Micromonas pusilla.
[So] Source:PLoS One;11(7):e0155839, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Micromonas is a unicellular motile alga within the Prasinophyceae, a green algal group that is related to land plants. This picoeukaryote (<2 µm diameter) is widespread in the marine environment but is not well understood at the cellular level. Here, we examine shifts in mRNA and protein expression over the course of the day-night cycle using triplicated mid-exponential, nutrient replete cultures of Micromonas pusilla CCMP1545. Samples were collected at key transition points during the diel cycle for evaluation using high-throughput LC-MS proteomics. In conjunction, matched mRNA samples from the same time points were sequenced using pair-ended directional Illumina RNA-Seq to investigate the dynamics and relationship between the mRNA and protein expression programs of M. pusilla. Similar to a prior study of the marine cyanobacterium Prochlorococcus, we found significant divergence in the mRNA and proteomics expression dynamics in response to the light:dark cycle. Additionally, expressional responses of genes and the proteins they encoded could also be variable within the same metabolic pathway, such as we observed in the oxygenic photosynthesis pathway. A regression framework was used to predict protein levels from both mRNA expression and gene-specific sequence-based features. Several features in the genome sequence were found to influence protein abundance including codon usage as well as 3' UTR length and structure. Collectively, our studies provide insights into the regulation of the proteome over a diel cycle as well as the relationships between transcriptional and translational programs in the widespread marine green alga Micromonas.
[Mh] Termos MeSH primário: Proteínas de Algas/genética
Clorófitas/genética
Regulação da Expressão Gênica de Plantas
Proteômica
RNA de Algas/genética
RNA Mensageiro/genética
[Mh] Termos MeSH secundário: Regiões 3' não Traduzidas
Proteínas de Algas/metabolismo
Clorófitas/metabolismo
Códon
Ontologia Genética
Anotação de Sequência Molecular
Fotoperíodo
Fotossíntese/genética
Biossíntese de Proteínas
RNA de Algas/metabolismo
RNA Mensageiro/metabolismo
Análise de Sequência de RNA
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (3' Untranslated Regions); 0 (Algal Proteins); 0 (Codon); 0 (RNA, Algal); 0 (RNA, Messenger)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170718
[Lr] Data última revisão:
170718
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160720
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0155839


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[PMID]:27395062
[Au] Autor:Hoang MH; Nguyen C; Pham HQ; Van Nguyen L; Hoang Duc L; Van Son L; Hai TN; Ha CH; Nhan LD; Anh HT; Thom le T; Quynh HT; Ha NC; Van Nhat P; Hong DD
[Ad] Endereço:Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
[Ti] Título:Transcriptome sequencing and comparative analysis of Schizochytrium mangrovei PQ6 at different cultivation times.
[So] Source:Biotechnol Lett;38(10):1781-9, 2016 Oct.
[Is] ISSN:1573-6776
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:OBJECTIVE: The heterotrophic marine microalga, Schizochytrium mangrovei PQ6, synthesizes large amounts of polyunsaturated fatty acids (PUFAs) with possible nutritional applications. We characterized the transcriptome of S. mangrovei PQ6, focusing on lipid metabolism pathways throughout growth. RESULT: Cell growth, total lipid, and docosahexaenoic acid (DHA, 22:6n-3) contents of S. mangrovei PQ6 in 500 ml batch cultures rapidly increased on day 1 in cultivation and reached their maximum levels on day 5. Maximum lipid accumulation in 500 ml batch cultures occurred on day 5, with total lipid and DHA contents reaching 33.2 ± 1.25% of dry cell weight (DCW) and 136 mg/g DCW, respectively. 11,025 unigenes, 28,617 unigenes and 18,480 unigenes from the transcriptomes of samples collected on day 1, 3, and 5 in cultivation were identified, respectively. These unigenes of the three samples were further assembled into 30,782 unigenes with an average size of 673 bp and N50 of 950 bp, and a total of 9,980 unigenes were annotated in public protein databases. 93 unigenes involved in lipid metabolism in which expression patterns corresponded with total lipid and DHA accumulation patterns were identified. CONCLUSION: The possible roles of PUFAs pathways, such as those mediated by fatty acid synthase, polyketide synthase, and desaturase/elongase, co-exist in S. mangrovei PQ6.
[Mh] Termos MeSH primário: Perfilação da Expressão Gênica/métodos
Metabolismo dos Lipídeos
Análise de Sequência de RNA/métodos
Estramenópilas/crescimento & desenvolvimento
[Mh] Termos MeSH secundário: Proteínas de Algas/genética
Proteínas de Algas/metabolismo
Técnicas de Cultura Celular por Lotes
Ácidos Docosa-Hexaenoicos/metabolismo
Redes Reguladoras de Genes
Anotação de Sequência Molecular
RNA de Algas/análise
Estramenópilas/genética
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Algal Proteins); 0 (RNA, Algal); 25167-62-8 (Docosahexaenoic Acids)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170203
[Lr] Data última revisão:
170203
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160711
[St] Status:MEDLINE
[do] DOI:10.1007/s10529-016-2165-5


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[PMID]:27029936
[Au] Autor:van Baren MJ; Bachy C; Reistetter EN; Purvine SO; Grimwood J; Sudek S; Yu H; Poirier C; Deerinck TJ; Kuo A; Grigoriev IV; Wong CH; Smith RD; Callister SJ; Wei CL; Schmutz J; Worden AZ
[Ad] Endereço:Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd, Moss Landing, CA, 95039, USA.
[Ti] Título:Evidence-based green algal genomics reveals marine diversity and ancestral characteristics of land plants.
[So] Source:BMC Genomics;17:267, 2016 Mar 31.
[Is] ISSN:1471-2164
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Prasinophytes are widespread marine green algae that are related to plants. Cellular abundance of the prasinophyte Micromonas has reportedly increased in the Arctic due to climate-induced changes. Thus, studies of these unicellular eukaryotes are important for marine ecology and for understanding Viridiplantae evolution and diversification. RESULTS: We generated evidence-based Micromonas gene models using proteomics and RNA-Seq to improve prasinophyte genomic resources. First, sequences of four chromosomes in the 22 Mb Micromonas pusilla (CCMP1545) genome were finished. Comparison with the finished 21 Mb genome of Micromonas commoda (RCC299; named herein) shows they share ≤8,141 of ~10,000 protein-encoding genes, depending on the analysis method. Unlike RCC299 and other sequenced eukaryotes, CCMP1545 has two abundant repetitive intron types and a high percent (26 %) GC splice donors. Micromonas has more genus-specific protein families (19 %) than other genome sequenced prasinophytes (11 %). Comparative analyses using predicted proteomes from other prasinophytes reveal proteins likely related to scale formation and ancestral photosynthesis. Our studies also indicate that peptidoglycan (PG) biosynthesis enzymes have been lost in multiple independent events in select prasinophytes and plants. However, CCMP1545, polar Micromonas CCMP2099 and prasinophytes from other classes retain the entire PG pathway, like moss and glaucophyte algae. Surprisingly, multiple vascular plants also have the PG pathway, except the Penicillin-Binding Protein, and share a unique bi-domain protein potentially associated with the pathway. Alongside Micromonas experiments using antibiotics that halt bacterial PG biosynthesis, the findings highlight unrecognized phylogenetic complexity in PG-pathway retention and implicate a role in chloroplast structure or division in several extant Viridiplantae lineages. CONCLUSIONS: Extensive differences in gene loss and architecture between related prasinophytes underscore their divergence. PG biosynthesis genes from the cyanobacterial endosymbiont that became the plastid, have been selectively retained in multiple plants and algae, implying a biological function. Our studies provide robust genomic resources for emerging model algae, advancing knowledge of marine phytoplankton and plant evolution.
[Mh] Termos MeSH primário: Evolução Biológica
Clorófitas/genética
Genoma de Planta
[Mh] Termos MeSH secundário: Embriófitas/genética
Genômica/métodos
Íntrons
Modelos Genéticos
Família Multigênica
Filogenia
Proteoma/genética
RNA de Algas/genética
Análise de Sequência de RNA
Transcriptoma
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Proteome); 0 (RNA, Algal)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160401
[St] Status:MEDLINE
[do] DOI:10.1186/s12864-016-2585-6


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[PMID]:20587772
[Au] Autor:González-Ballester D; Casero D; Cokus S; Pellegrini M; Merchant SS; Grossman AR
[Ad] Endereço:Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, USA. q62gobad@uco.es
[Ti] Título:RNA-seq analysis of sulfur-deprived Chlamydomonas cells reveals aspects of acclimation critical for cell survival.
[So] Source:Plant Cell;22(6):2058-84, 2010 Jun.
[Is] ISSN:1532-298X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The Chlamydomonas reinhardtii transcriptome was characterized from nutrient-replete and sulfur-depleted wild-type and snrk2.1 mutant cells. This mutant is null for the regulatory Ser-Thr kinase SNRK2.1, which is required for acclimation of the alga to sulfur deprivation. The transcriptome analyses used microarray hybridization and RNA-seq technology. Quantitative RT-PCR evaluation of the results obtained by these techniques showed that RNA-seq reports a larger dynamic range of expression levels than do microarray hybridizations. Transcripts responsive to sulfur deprivation included those encoding proteins involved in sulfur acquisition and assimilation, synthesis of sulfur-containing metabolites, Cys degradation, and sulfur recycling. Furthermore, we noted potential modifications of cellular structures during sulfur deprivation, including the cell wall and complexes associated with the photosynthetic apparatus. Moreover, the data suggest that sulfur-deprived cells accumulate proteins with fewer sulfur-containing amino acids. Most of the sulfur deprivation responses are controlled by the SNRK2.1 protein kinase. The snrk2.1 mutant exhibits a set of unique responses during both sulfur-replete and sulfur-depleted conditions that are not observed in wild-type cells; the inability of this mutant to acclimate to S deprivation probably leads to elevated levels of singlet oxygen and severe oxidative stress, which ultimately causes cell death. The transcriptome results for wild-type and mutant cells strongly suggest the occurrence of massive changes in cellular physiology and metabolism as cells become depleted for sulfur and reveal aspects of acclimation that are likely critical for cell survival.
[Mh] Termos MeSH primário: Chlamydomonas reinhardtii/genética
Perfilação da Expressão Gênica
RNA de Algas/genética
Análise de Sequência de RNA/métodos
Enxofre/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Chlamydomonas reinhardtii/metabolismo
Dados de Sequência Molecular
Análise de Sequência com Séries de Oligonucleotídeos/métodos
RNA de Algas/metabolismo
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Alinhamento de Sequência
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (RNA, Algal); 0 (RNA, Messenger); 70FD1KFU70 (Sulfur)
[Em] Mês de entrada:1010
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:100701
[St] Status:MEDLINE
[do] DOI:10.1105/tpc.109.071167


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[PMID]:20532888
[Au] Autor:Ahn JW; Yin CJ; Liu JR; Jeong WJ
[Ad] Endereço:Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, 111 Gwahangno, Yuseong-gu, Daejeon, 305-806, Korea.
[Ti] Título:Cucumber mosaic virus 2b protein inhibits RNA silencing pathways in green alga Chlamydomonas reinhardtii.
[So] Source:Plant Cell Rep;29(9):967-75, 2010 Sep.
[Is] ISSN:1432-203X
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The functions of RNA silencing are repression of endogenous gene expression and antiviral defense in plants and animals. Cucumber mosaic virus 2b (CMV2b) is a suppressor of RNA silencing in higher plants. In the present study, we evaluated the RNA silencing suppressor activity of CMV2b in Chlamydomonas reinhardtii. Before transformation, we modified CMV2b codons to increase the GC content for optimal expression in C. reinhardtii. Inhibition of Maa7 silencing was detected in CMV2b-expressing Maa7-IR44 strains, indicating that CMV2b suppressed siRNA pathways in C. reinhardtii as in higher plants. In addition, mRNA expression targeted for cleavage by miRNA was significantly higher in CMV2b-expressing strains, but increased accumulation of miRNA was not detected. These results indicate that the suppression of miRNA pathways is mediated by CMV2b in C. reinhardtii. Interestingly, expression of both Argonaute 1 (AGO1) and Dicer-like 1 (DCL1), regulated by a bidirectional promoter, was reduced in CMV2b-expressing strains, suggesting that CMV2b may affect transcription factors involved in RNA silencing pathways. Furthermore, reduction of AGO2 and AGO3 expression was detected in CMV2b-expressing strains. Taken together, our results demonstrate that CMV2b may suppress both siRNA and miRNA pathways, and also impair AGOs and DCL1 expression in C. reinhardtii.
[Mh] Termos MeSH primário: Chlamydomonas reinhardtii/genética
Interferência de RNA
Proteínas Virais/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Algas/metabolismo
Sequência de Aminoácidos
Sequência de Bases
Cucumovirus/genética
Cucumovirus/metabolismo
Regulação da Expressão Gênica
MicroRNAs/genética
Dados de Sequência Molecular
RNA de Algas/genética
RNA Mensageiro/genética
Proteínas Virais/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (2b protein, cucumber mosaic virus); 0 (Algal Proteins); 0 (MicroRNAs); 0 (RNA, Algal); 0 (RNA, Messenger); 0 (Viral Proteins)
[Em] Mês de entrada:1011
[Cu] Atualização por classe:171004
[Lr] Data última revisão:
171004
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:100610
[St] Status:MEDLINE
[do] DOI:10.1007/s00299-010-0882-0


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[PMID]:20498339
[Au] Autor:Pootakham W; Gonzalez-Ballester D; Grossman AR
[Ad] Endereço:Department of Biology, Stanford University, Stanford, California 94305-5020, USA. wirulda@gmail.com
[Ti] Título:Identification and regulation of plasma membrane sulfate transporters in Chlamydomonas.
[So] Source:Plant Physiol;153(4):1653-68, 2010 Aug.
[Is] ISSN:1532-2548
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Chlamydomonas (Chlamydomonas reinhardtii) exhibits several responses following exposure to sulfur (S)-deprivation conditions, including an increased efficiency of import and assimilation of the sulfate anion (SO(4)(2-)). Aspects of SO(4)(2-) transport during S-replete and S-depleted conditions were previously studied, although the transporters had not been functionally identified. We employed a reverse genetics approach to identify putative SO(4)(2-) transporters, examine their regulation, establish their biogenesis and subcellular locations, and explore their functionality. Upon S starvation of wild-type Chlamydomonas cells, the accumulation of transcripts encoding the putative SO(4)(2-) transporters SLT1 (for SAC1-like transporter 1), SLT2, and SULTR2 markedly increased, suggesting that these proteins function in high-affinity SO(4)(2-) transport. The Chlamydomonas sac1 and snrk2.1 mutants (defective for acclimation to S deprivation) exhibited much less of an increase in the levels of SLT1, SLT2, and SULTR2 transcripts and their encoded proteins in response to S deprivation compared with wild-type cells. All three transporters were localized to the plasma membrane, and their rates of turnover were significantly impacted by S availability; the turnover of SLT1 and SLT2 was proteasome dependent, while that of SULTR2 was proteasome independent. Finally, mutants identified for each of the S-deprivation-responsive transporters were used to establish their critical role in the transport of SO(4)(2-) into S-deprived cells.
[Mh] Termos MeSH primário: Proteínas de Algas/metabolismo
Chlamydomonas reinhardtii/genética
Proteínas de Membrana Transportadoras/metabolismo
Enxofre/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Algas/genética
Chlamydomonas reinhardtii/metabolismo
Biblioteca Gênica
Proteínas de Membrana Transportadoras/genética
Dados de Sequência Molecular
Mutagênese Insercional
Complexo de Endopeptidases do Proteassoma/metabolismo
RNA de Algas/genética
Sulfatos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Algal Proteins); 0 (Membrane Transport Proteins); 0 (RNA, Algal); 0 (Sulfates); 70FD1KFU70 (Sulfur); EC 3.4.25.1 (Proteasome Endopeptidase Complex)
[Em] Mês de entrada:1010
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:100526
[St] Status:MEDLINE
[do] DOI:10.1104/pp.110.157875


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[PMID]:20375110
[Au] Autor:Imamura S; Terashita M; Ohnuma M; Maruyama S; Minoda A; Weber AP; Inouye T; Sekine Y; Fujita Y; Omata T; Tanaka K
[Ad] Endereço:Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan.
[Ti] Título:Nitrate assimilatory genes and their transcriptional regulation in a unicellular red alga Cyanidioschyzon merolae: genetic evidence for nitrite reduction by a sulfite reductase-like enzyme.
[So] Source:Plant Cell Physiol;51(5):707-17, 2010 May.
[Is] ISSN:1471-9053
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Cyanidioschyzon merolae is a unicellular red alga living in acid hot springs, which is able to grow on ammonium, as well as nitrate as sole nitrogen source. Based on the complete genome sequence, proteins for nitrate utilization, nitrate transporter (NRT) and nitrate reductase (NR), were predicted to be encoded by the neighboring nuclear genes CMG018C and CMG019C, respectively, but no typical nitrite reductase (NiR) gene was found by similarity searches. On the other hand, two candidate genes for sulfite reductase (SiR) were found, one of which (CMG021C) is located next to the above-noted nitrate-related genes. Given that transcripts of CMG018C, CMG019C and CMG021C accumulate in nitrate-containing media, but are repressed by ammonium, and that SiR and NiR are structurally related enzymes, we hypothesized that the CMG021C gene product functions as an NiR in C. merolae. To test this hypothesis, we developed a method for targeted gene disruption in C. merolae. In support of our hypothesis, we found that a CMG021G null mutant in comparison with the parental strain showed decreased cell growth in nitrate-containing but not in ammonium-containing media. Furthermore, expression of CMG021C in the nirA mutant of a cyanobacterium, Leptolyngbya boryana (formerly Plectonema boryanum), could genetically complement the NiR defect. Immunofluorescent analysis indicated the localization of CMG021C in chloroplasts, and hence we propose an overall scheme for nitrate assimilation in C. merolae.
[Mh] Termos MeSH primário: Proteínas de Algas/metabolismo
Nitrito Redutases/genética
Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo
Rodófitas/enzimologia
[Mh] Termos MeSH secundário: Proteínas de Algas/genética
Proteínas de Transporte de Ânions/genética
Proteínas de Transporte de Ânions/metabolismo
Regulação da Expressão Gênica
Técnicas de Inativação de Genes
Teste de Complementação Genética
Mutação
Nitrato Redutases/genética
Nitrato Redutases/metabolismo
Nitratos/metabolismo
Nitrito Redutases/metabolismo
Oxirredutases atuantes sobre Doadores de Grupo Enxofre/genética
RNA de Algas/genética
Rodófitas/genética
Rodófitas/crescimento & desenvolvimento
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Algal Proteins); 0 (Anion Transport Proteins); 0 (Nitrates); 0 (RNA, Algal); 0 (nitrate transporters); EC 1.7.- (Nitrate Reductases); EC 1.7.- (Nitrite Reductases); EC 1.8.- (Oxidoreductases Acting on Sulfur Group Donors)
[Em] Mês de entrada:1007
[Cu] Atualização por classe:101118
[Lr] Data última revisão:
101118
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:100409
[St] Status:MEDLINE
[do] DOI:10.1093/pcp/pcq043


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[PMID]:20360179
[Au] Autor:Judelson HS; Ah-Fong AM; Fabritius AL
[Ad] Endereço:Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, USA. Howard.Judelson@ucr.edu
[Ti] Título:An RNA symbiont enhances heat tolerance and secondary homothallism in the oomycete Phytophthora infestans.
[So] Source:Microbiology;156(Pt 7):2026-34, 2010 Jul.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Some strains of Phytophthora infestans, the potato late blight pathogen, harbour a small extrachromosomal RNA called PiERE1. A previous study reported that this RNA symbiont does not noticeably affect its host. Here it is revealed that PiERE1 exerts subtle effects on P. infestans, which result in greater thermotolerance during growth and an increase in secondary homothallism, i.e. oospore formation in the absence of the opposite mating type. The interaction can be considered mutualistic since these traits may increase the fitness of P. infestans in nature. Assays of biomarkers for cellular stress revealed that an Hsp70 chaperone was upregulated by PiERE1. A genome-wide search for more members of the Hsp70 family identified ten belonging to the DnaK subfamily, one in the Hsp110/SSE subfamily, and pseudogenes. Four DnaK subfamily genes encoding predicted cytoplasmic or endoplasmic reticulum proteins were upregulated in strains harbouring PiERE1. This may explain the greater thermotolerance conferred by the RNA element, and suggests that Hsp70 may be a useful biomarker for testing organisms for the cellular effects of symbiotic elements.
[Mh] Termos MeSH primário: Interações Hospedeiro-Parasita
Lycopersicon esculentum/fisiologia
Phytophthora infestans/fisiologia
RNA de Algas/metabolismo
Simbiose
[Mh] Termos MeSH secundário: Proteínas de Algas/genética
Proteínas de Algas/metabolismo
Proteínas de Choque Térmico HSP72/genética
Proteínas de Choque Térmico HSP72/metabolismo
Temperatura Alta
Lycopersicon esculentum/parasitologia
Dados de Sequência Molecular
Phytophthora infestans/genética
Phytophthora infestans/crescimento & desenvolvimento
Doenças das Plantas/parasitologia
RNA de Algas/genética
Estresse Fisiológico
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Algal Proteins); 0 (HSP72 Heat-Shock Proteins); 0 (RNA, Algal)
[Em] Mês de entrada:1010
[Cu] Atualização por classe:100702
[Lr] Data última revisão:
100702
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:100403
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.039305-0



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