Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Type of Medium
Language
Year
  • 1
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 16 February 2010, Vol.107(7), pp.3245-50
    Description: Bacterial group II introns encode maturase proteins required for splicing. In organelles of photosynthetic land plants, most of the group II introns have lost the reading frames for maturases. Here, we show that the plastidial maturase MatK not only interacts with its encoding intron within trnK-UUU, but also with six additional group II introns, all belonging to intron subclass IIA. Mapping analyses of RNA binding sites revealed MatK to recognize multiple regions within the trnK intron. Organellar group II introns are considered to be the ancestors of nuclear spliceosomal introns. That MatK associates with multiple intron ligands makes it an attractive model for an early trans-acting nuclear splicing activity.
    Keywords: Chloroplasts -- Genetics ; Endoribonucleases -- Genetics ; Introns -- Genetics ; Nucleotidyltransferases -- Genetics ; RNA Splicing -- Genetics ; RNA, Catalytic -- Genetics ; Tobacco -- Genetics
    ISSN: 00278424
    E-ISSN: 1091-6490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    In: Plant Journal, December 2010, Vol.64(6), pp.948-959
    Description: Plant mitochondrial genomes are split into sub‐genomes, i.e. genes are distributed across various sub‐genomic molecules. To investigate whether copy numbers vary between individual mitochondrial genes, we used quantitative real‐time PCR in combination with flow cytometric determination of nuclear DNA quantities to determine absolute per‐cell‐copy numbers of four mitochondrial genes in various Arabidopsis organs and the leaves of tobacco () and barley (). The copy numbers of the investigated mitochondrial genes (, , and ) not only differed from each other, but also varied between organs and changed during the development of cotyledons and leaves in Arabidopsis. We found no correlation between altered gene copy numbers, transcript levels and O consumption. However, per cell, both the number of mitochondria and the number of gene copies increased with growing cell size. Gene copy numbers varied from approximately 40 ( in young leaves) to approximately 280 ( in mature leaves), and the mean number of mitochondria was approximately 300 in young leaves and 450 in mature leaves. Thus, cells are polyploid with respect to their mitochondrial genomes, but individual mitochondria may contain only part of the genome or even no DNA at all. Our data supports structural models of the mitochondrial genome in non‐dividing cells of angiosperms that predict localization of the genes on sub‐genomic molecules rather than master chromosomes. The data indicate control of the number of individual genes according to the genotype and developmental program(s) via amplification and/or degradation of sub‐genomic molecules.
    Keywords: Endopolyploidy ; Mitochondrial Genome ; Mitochondrial Replication ; Mitochondrial Transcription ; Arabidopsis ; Nicotiana
    ISSN: 0960-7412
    E-ISSN: 1365-313X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Plant Methods, 01 December 2011, Vol.7(1), p.47
    Description: Abstract Transcriptional activity of entire genes in chloroplasts is usually assayed by run-on analyses. To determine not only the overall intensity of transcription of a gene, but also the rate of transcription from a particular promoter, we created the Reverse RNase Protection Assay (RePro): in-organello run-on transcription coupled to RNase protection to define distinct transcript ends during transcription. We demonstrate successful application of RePro in plastid promoter analysis and transcript 3' end processing.
    Keywords: Chloroplast ; Plastid Transcription ; Promoters ; RNA Processing ; Run on Transcription Assay ; Rnase Protection Assay ; Botany
    ISSN: 1746-4811
    E-ISSN: 1746-4811
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: The Plant cell, January 2012, Vol.24(1), pp.123-36
    Description: Gene expression in plastids of higher plants is dependent on two different transcription machineries, a plastid-encoded bacterial-type RNA polymerase (PEP) and a nuclear-encoded phage-type RNA polymerase (NEP), which recognize distinct types of promoters. The division of labor between PEP and NEP during plastid development and in mature chloroplasts is unclear due to a lack of comprehensive information on promoter usage. Here, we present a thorough investigation into the distribution of PEP and NEP promoters within the plastid genome of barley (Hordeum vulgare). Using a novel differential RNA sequencing approach, which discriminates between primary and processed transcripts, we obtained a genome-wide map of transcription start sites in plastids of mature first leaves. PEP-lacking plastids of the albostrians mutant allowed for the unambiguous identification of NEP promoters. We observed that the chloroplast genome contains many more promoters than genes. According to our data, most genes (including genes coding for photosynthesis proteins) have both PEP and NEP promoters. We also detected numerous transcription start sites within operons, indicating transcriptional uncoupling of genes in polycistronic gene clusters. Moreover, we mapped many transcription start sites in intergenic regions and opposite to annotated genes, demonstrating the existence of numerous noncoding RNA candidates.
    Keywords: Chloroplasts -- Genetics ; DNA-Directed RNA Polymerases -- Metabolism ; Hordeum -- Enzymology ; Plastids -- Enzymology ; RNA, Untranslated -- Genetics
    ISSN: 10404651
    E-ISSN: 1532-298X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Genome announcements, 18 August 2016, Vol.4(4)
    Description: Rheinheimera sp. strain SA_1 is an iron-depositing bacterium for which we report a draft genome sequence. Strain SA_1 was isolated from iron backwash sludge of a waterworks in Germany. The Illumina MiSeq technique was used to sequence the genome of the strain.
    Keywords: Biology;
    ISSN: 2169-8287
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Journal of Plant Physiology, 2011, Vol.168(12), pp.1345-1360
    Description: Although genomes of mitochondria and plastids are very small compared to those of their bacterial ancestors, the transcription machineries of these organelles are of surprising complexity. With respect to the number of different RNA polymerases per organelle, the extremes are represented on one hand by chloroplasts of eudicots which use one bacterial-type RNA polymerase and two phage-type RNA polymerases to transcribe their genes, and on the other hand by possessing three mitochondrial RNA polymerases of the phage type. Transcription of genes/operons is often driven by multiple promoters in both organelles. This review describes the principle components of the transcription machineries (RNA polymerases, transcription factors, promoters) and the division of labor between the different RNA polymerases. While regulation of transcription in mitochondria seems to be only of limited importance, the plastid genes of higher plants respond to exogenous and endogenous cues rather individually by altering their transcriptional activities.
    Keywords: Chloroplast Transcription ; Mitochondrial Transcription ; Promoter ; Regulation of Transcription ; RNA Polymerase ; Botany
    ISSN: 0176-1617
    E-ISSN: 16181328
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    In: Plant Journal, May 2007, Vol.50(4), pp.710-722
    Description: Little is known about DNA and RNA metabolism during leaf development and aging in the model organism Arabidopsis. Therefore we examined the nuclear and plastidial DNA content of tissue ranging in age from 2‐day‐old cotyledons to 37‐day‐old senescent rosette leaves. Flow‐cytometric analysis showed an increase in nuclear DNA ploidy levels of up to 128 genome copies per nucleus in older leaves. The copy numbers of nuclear 18S‐rRNA genes were determined to be 700 ± 60 per haploid genome. Adjusted to the average level of nuclear DNA polyploidism per cell, plastome copy numbers varied from about 1000 to 1700 per cell without significant variation during development from young to old rosette leaves. The transcription activity of all studied plastid genes was significantly reduced in older rosette leaves in comparison to that in young leaves. In contrast, levels of plastidial transcript accumulation showed different patterns. In the case of , transcripts accumulated to even higher levels in older leaves, indicating that differential regulation of plastidial gene expression occurs during leaf development. Examination of promoter activity from and genes by primer extension analyses revealed that two RNA polymerases (NEP and PEP) transcribe these genes in cotyledons as well as in young and senescent leaves. However, PEP may have a more prominent role in older rosette leaves than in young cotyledons. We conclude that in cotyledons or leaves of different ages plastidial gene expression is regulated at the transcriptional and post‐transcriptional levels, but not by plastome copy number.
    Keywords: Arabidopsis ; Leaf Development ; Ploidy ; Plastid Genome Copy Number ; Chloroplast Transcription
    ISSN: 0960-7412
    E-ISSN: 1365-313X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Plant molecular biology, October 2016, Vol.92(3), pp.357-69
    Description: We identified sequence motifs, which enhance or reduce the ability of the Arabidopsis phage-type RNA polymerases RPOTm (mitochondrial RNAP), RPOTp (plastidial RNAP), and RPOTmp (active in both organelles) to recognize their promoters in vitro with help of a 'specificity loop'. The importance of this data for the evolution and function of the organellar RNA polymerases is discussed. The single-subunit RNA polymerase (RNAP) of bacteriophage T7 is able to perform all steps of transcription without additional transcription factors. Dicotyledonous plants possess three phage-type RNAPs, RPOTm-the mitochondrial RNAP, RPOTp-the plastidial RNAP, and RPOTmp-an RNAP active in both organelles. RPOTm and RPOTp, like the T7 polymerase, are able to recognize promoters, while RPOTmp displays no significant promoter specificity in vitro. To find out which promoter motifs are crucial for recognition by the polymerases we performed in vitro transcription assays with recombinant Arabidopsis RPOTm and RPOTp enzymes. By comparing different truncated and mutagenized promoter constructs, we observed the same minimal promoter sequence supposed to be needed in vivo for transcription initiation. Moreover, we identified elements of core and flanking sequences, which are of critical importance for promoter recognition and activity in vitro. We further intended to reveal why RPOTmp does not efficiently recognize promoters in vitro and if promoter recognition is based on a structurally defined specificity loop of the plant enzymes as described for the yeast and T7 RNAPs. Interestingly, the exchange of only three amino acids within the putative specificity loop of RPOTmp enabled the enzyme for specific promoter transcription in vitro. Thus, also in plant phage-type RNAPs the specificity loop is engaged in promoter recognition. The results are discussed with respect to their relevance for transcription in organello and to the evolution of RPOT enzymes including the divergence of their functions.
    Keywords: Arabidopsis ; Chloroplast RNA Polymerase ; Mitochondrial RNA Polymerase ; Phage-Type RNA Polymerase ; Promoter Recognition ; Arabidopsis -- Genetics ; DNA-Directed RNA Polymerases -- Metabolism ; Promoter Regions, Genetic -- Genetics
    ISSN: 01674412
    E-ISSN: 1573-5028
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Plant methods, 2011, Vol.7
    Description: Transcriptional activity of entire genes in chloroplasts is usually assayed by run-on analyses. To determine not only the overall intensity of transcription of a gene, but also the rate of transcription from a particular promoter, we created the Reverse RNase Protection Assay (RePro): in-organello run-on transcription coupled to RNase protection to define distinct transcript ends during transcription. We demonstrate successful application of RePro in plastid promoter analysis and transcript 3' end processing. ; Includes references ; 13 p.
    Keywords: Genes ; Ribonucleases ; Transcription (Genetics) ; Chloroplasts
    ISSN: 1746-4811
    Source: AGRIS (Food and Agriculture Organization of the United Nations)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Methods in molecular biology (Clifton, N.J.), 2011, Vol.774, pp.171-82
    Description: The regulation of gene expression is still one of the major issues in modern plant molecular biology. The amount of RNA in a cell is regulated by both transcriptional and posttranscriptional events. Methods to determine these steady-state levels of RNAs, such as Northern analysis, ribonuclease protection assay (RPA), and quantitative real-time PCR, do not discriminate between regulation by de novo RNA synthesis and the influence by degradation or stabilization. To assess the rate of transcription of individual genes, run-on transcription is utilized. To this end, isolated chloroplasts are used in brief in vitro transcription reactions in the presence of radiolabeled nucleotides, with a subsequent hybridization of the isolated RNA with DNA fragments spotted on membranes. Here, we describe a protocol for run-on transcription in chloroplasts isolated from Arabidopsis leaves and present data on the transcriptional activity of several plastid genes in detached leaves of different Arabidopsis ecotypes.
    Keywords: Genetic Techniques ; Transcription, Genetic ; Arabidopsis -- Genetics ; Chloroplasts -- Genetics ; RNA, Chloroplast -- Biosynthesis
    ISBN: 9781617792335
    ISSN: 10643745
    E-ISSN: 1940-6029
    Source: MEDLINE/PubMed (U.S. National Library of Medicine)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages