501
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Gendall AR, Levy YY, Wilson A, Dean C. The VERNALIZATION 2 gene mediates the epigenetic regulation of vernalization in Arabidopsis. Cell 2001; 107:525-35. [PMID: 11719192 DOI: 10.1016/s0092-8674(01)00573-6] [Citation(s) in RCA: 357] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The acceleration of flowering by a long period of low temperature, vernalization, is an adaptation that ensures plants overwinter before flowering. Vernalization induces a developmental state that is mitotically stable, suggesting that it may have an epigenetic basis. The VERNALIZATION2 (VRN2) gene mediates vernalization and encodes a nuclear-localized zinc finger protein with similarity to Polycomb group (PcG) proteins of plants and animals. In wild-type Arabidopsis, vernalization results in the stable reduction of the levels of the floral repressor FLC. In vrn2 mutants, FLC expression is downregulated normally in response to vernalization, but instead of remaining low, FLC mRNA levels increase when plants are returned to normal temperatures. VRN2 function therefore stably maintains FLC repression after a cold treatment, serving as a mechanism for the cellular memory of vernalization.
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MESH Headings
- Agrobacterium tumefaciens/genetics
- Amino Acid Motifs
- Amino Acid Sequence
- Arabidopsis/genetics
- Arabidopsis/growth & development
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/physiology
- Carrier Proteins/genetics
- Carrier Proteins/physiology
- Chromosomes, Artificial, Yeast/genetics
- Cloning, Molecular
- Codon/genetics
- Cosmids/genetics
- DNA, Complementary/genetics
- DNA-Binding Proteins
- Deoxyribonuclease I/metabolism
- Gene Library
- Genes, Plant
- Genetic Vectors/genetics
- MADS Domain Proteins/antagonists & inhibitors
- MADS Domain Proteins/biosynthesis
- MADS Domain Proteins/genetics
- MADS Domain Proteins/physiology
- Molecular Sequence Data
- Nuclear Proteins/genetics
- Nuclear Proteins/physiology
- Plant Proteins/antagonists & inhibitors
- Plant Proteins/biosynthesis
- Plant Proteins/genetics
- Plant Proteins/physiology
- Protein Structure, Tertiary
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Plant/biosynthesis
- RNA, Plant/genetics
- Recombinant Fusion Proteins/physiology
- Seasons
- Sequence Alignment
- Sequence Homology, Amino Acid
- Temperature
- Transcription Factors/chemistry
- Zinc Fingers/genetics
- Zinc Fingers/physiology
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Affiliation(s)
- A R Gendall
- Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, NR4 7UH, Norwich, United Kingdom
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502
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Zhang X, Feschotte C, Zhang Q, Jiang N, Eggleston WB, Wessler SR. P instability factor: an active maize transposon system associated with the amplification of Tourist-like MITEs and a new superfamily of transposases. Proc Natl Acad Sci U S A 2001; 98:12572-7. [PMID: 11675493 PMCID: PMC60095 DOI: 10.1073/pnas.211442198] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Miniature inverted-repeat transposable elements (MITEs) are widespread and abundant in both plant and animal genomes. Despite the discovery and characterization of many MITE families, their origin and transposition mechanism are still poorly understood, largely because MITEs are nonautonomous elements with no coding capacity. The starting point for this study was P instability factor (PIF), an active DNA transposable element family from maize that was first identified following multiple mutagenic insertions into exactly the same site in intron 2 of the maize anthocyanin regulatory gene R. In this study we report the isolation of a maize Tourist-like MITE family called miniature PIF (mPIF) that shares several features with PIF elements, including identical terminal inverted repeats, similar subterminal sequences, and an unusual but striking preference for an extended 9-bp target site. These shared features indicate that mPIF and PIF elements were amplified by the same or a closely related transposase. This transposase was identified through the isolation of several PIF elements and the identification of one element (called PIFa) that cosegregated with PIF activity. PIFa encodes a putative protein with homologs in Arabidopsis, rice, sorghum, nematodes, and a fungus. Our data suggest that PIFa and these PIF-like elements belong to a new eukaryotic DNA transposon superfamily that is distantly related to the bacterial IS5 group and are responsible for the origin and spread of Tourist-like MITEs.
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Affiliation(s)
- X Zhang
- Botany Department, University of Georgia, Athens, GA 30602, USA
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503
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Baldwin TC, Handford MG, Yuseff MI, Orellana A, Dupree P. Identification and characterization of GONST1, a golgi-localized GDP-mannose transporter in Arabidopsis. THE PLANT CELL 2001; 13:2283-95. [PMID: 11595802 PMCID: PMC139159 DOI: 10.1105/tpc.010247] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2001] [Accepted: 08/14/2001] [Indexed: 05/17/2023]
Abstract
Transport of nucleotide sugars across the Golgi apparatus membrane is required for the luminal synthesis of a variety of plant cell surface components. We identified an Arabidopsis gene encoding a nucleotide sugar transporter (designated GONST1) that we have shown by transient gene expression to be localized to the Golgi. GONST1 complemented a GDP-mannose transport-defective yeast mutant (vrg4-2), and Golgi-rich vesicles from the complemented strain displayed increased GDP-mannose transport activity. GONST1 promoter::beta-glucuronidase studies suggested that this gene is expressed ubiquitously. The identification of a Golgi-localized nucleotide sugar transporter from plants will allow the study of the importance of this class of proteins in the synthesis of plant cell surface components such as cell wall polysaccharides.
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Affiliation(s)
- T C Baldwin
- Department of Biochemistry, University of Cambridge, Building O, Downing Site, Cambridge CB2 1QW, United Kingdom
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504
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Baldwin TC, Handford MG, Yuseff MI, Orellana A, Dupree P. Identification and characterization of GONST1, a golgi-localized GDP-mannose transporter in Arabidopsis. THE PLANT CELL 2001. [PMID: 11595802 DOI: 10.1105/tpc.13.10.2283] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Transport of nucleotide sugars across the Golgi apparatus membrane is required for the luminal synthesis of a variety of plant cell surface components. We identified an Arabidopsis gene encoding a nucleotide sugar transporter (designated GONST1) that we have shown by transient gene expression to be localized to the Golgi. GONST1 complemented a GDP-mannose transport-defective yeast mutant (vrg4-2), and Golgi-rich vesicles from the complemented strain displayed increased GDP-mannose transport activity. GONST1 promoter::beta-glucuronidase studies suggested that this gene is expressed ubiquitously. The identification of a Golgi-localized nucleotide sugar transporter from plants will allow the study of the importance of this class of proteins in the synthesis of plant cell surface components such as cell wall polysaccharides.
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Affiliation(s)
- T C Baldwin
- Department of Biochemistry, University of Cambridge, Building O, Downing Site, Cambridge CB2 1QW, United Kingdom
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505
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Bercury SD, Panavas T, Irenze K, Walker EL. Molecular analysis of the Doppia transposable element of maize. PLANT MOLECULAR BIOLOGY 2001; 47:341-51. [PMID: 11587506 DOI: 10.1023/a:1011606529513] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Doppia (Dop) transposable elements were first identified from element termini found in the upstream portions of certain alleles of the pl1 and r1 loci of maize. At the r1 locus, these Dop end sequences are present in a region called sigma, which functions as the promoter for the S genes of the R-r haplotype, and which is required for efficient epigenetic modification of the S genes during paramutation. In order to better understand the significance of the Dop element sequences at R-r, and to investigate the Dop-encoded products that might regulate r1 genes in this haplotype, we have cloned a more complete Dop element, Dop4. The Dop4 element can encode two proteins that have strong sequence similarity to the TnpA and TnpD proteins of the well characterized maize transposable element En/Spm. The DOPA protein, which is similar to TnpA of En/Spm, is shown to bind to short, subterminal repeat motifs located in the Dop element ends. Like TnpA, DOPA promotes intermolecular associations between DNA molecules. In contrast to the activity of TnpA, which is a transcriptional repressor of En/Spm, DOPA activates expression of reporter genes driven by either the Dop promoter or sigma in transient expression assays.
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MESH Headings
- Amino Acid Sequence
- Arabidopsis/genetics
- Cloning, Molecular
- DNA Transposable Elements/genetics
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA, Plant/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Gene Expression Regulation, Plant
- Genome, Plant
- Genomic Library
- Glucuronidase/genetics
- Glucuronidase/metabolism
- Luciferases/genetics
- Luciferases/metabolism
- Molecular Sequence Data
- Plants, Genetically Modified/genetics
- Protein Binding
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
- Zea mays/genetics
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Affiliation(s)
- S D Bercury
- Biology Department, University of Massachusetts, Amherst 01003, USA
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506
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Huang Y, Qin W, Wan D, Zhao X, Gu J. Computational analysis and prediction for exons of PAC579 genomic sequence. SCIENCE IN CHINA. SERIES C, LIFE SCIENCES 2001; 44:533-540. [PMID: 18726399 DOI: 10.1007/bf02882396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2001] [Indexed: 05/26/2023]
Abstract
To isolate the novel genes related to human hepatocellular carcinoma (HCC), we sequenced P1-derived artificial chromosome PAC579 (D17S926 locus) mapped in the minimum LOH (loss of heterozygosity) deletion region of chromosome 17p13.3 in HCC. Four novel genes mapped in this genomic sequence area were isolated and cloned by wet-lab experiments, and the exons of these genes were located. 0-60 kb of this genomic sequence including the genes of interest was scanned with five different computational exon prediction programs as well as four splice site recognition programs. After analyzing and comparing the computationally predicted results with the wet-lab experiment results, some potential exons were predicted in the genomic sequence by using these programs.
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Affiliation(s)
- Y Huang
- Shanghai Cancer Institute, China.
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507
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Zolman BK, Monroe-Augustus M, Thompson B, Hawes JW, Krukenberg KA, Matsuda SP, Bartel B. chy1, an Arabidopsis mutant with impaired beta-oxidation, is defective in a peroxisomal beta-hydroxyisobutyryl-CoA hydrolase. J Biol Chem 2001; 276:31037-46. [PMID: 11404361 DOI: 10.1074/jbc.m104679200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The Arabidopsis chy1 mutant is resistant to indole-3-butyric acid, a naturally occurring form of the plant hormone auxin. Because the mutant also has defects in peroxisomal beta-oxidation, this resistance presumably results from a reduced conversion of indole-3-butyric acid to indole-3-acetic acid. We have cloned CHY1, which appears to encode a peroxisomal protein 43% identical to a mammalian valine catabolic enzyme that hydrolyzes beta-hydroxyisobutyryl-CoA. We demonstrated that a human beta-hydroxyisobutyryl-CoA hydrolase functionally complements chy1 when redirected from the mitochondria to the peroxisomes. We expressed CHY1 as a glutathione S-transferase (GST) fusion protein and demonstrated that purified GST-CHY1 hydrolyzes beta-hydroxyisobutyryl-CoA. Mutagenesis studies showed that a glutamate that is catalytically essential in homologous enoyl-CoA hydratases was also essential in CHY1. Mutating a residue that is differentially conserved between hydrolases and hydratases established that this position is relevant to the catalytic distinction between the enzyme classes. It is likely that CHY1 acts in peroxisomal valine catabolism and that accumulation of a toxic intermediate, methacrylyl-CoA, causes the altered beta-oxidation phenotypes of the chy1 mutant. Our results support the hypothesis that the energy-intensive sequence unique to valine catabolism, where an intermediate CoA ester is hydrolyzed and a new CoA ester is formed two steps later, avoids methacrylyl-CoA accumulation.
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Affiliation(s)
- B K Zolman
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005, USA
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508
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Salvemini F, Marini A, Riccio A, Patriarca EJ, Chiurazzi M. Functional characterization of an ammonium transporter gene from Lotus japonicus. Gene 2001; 270:237-43. [PMID: 11404021 DOI: 10.1016/s0378-1119(01)00470-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
NH(4)(+) is the main product of symbiotic nitrogen fixation and the external concentration of combined nitrogen plays a key regulatory role in all the different step of plant-rhizobia interaction. We report the cloning and characterization of the first member of the ammonium transporter family, LjAMT1;1 from a leguminous plant, Lotus japonicus. Sequence analysis reveals a close relationship to plant transporters of the AMT1 family. The wild type and two mutated versions of LjAMT1;1 were expressed and functionally characterized in yeast. LjAMT1;1 is transcribed in roots, leaves and nodules of L. japonicus plants grown under low nitrogen conditions, consistent with a role in uptake of NH(4)(+) by the plant cells.
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Affiliation(s)
- F Salvemini
- International Institute of Genetics and Biophysics. Via Marconi 12, 80125, Napoli, Italy
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509
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Bevan M, Mayer K, White O, Eisen JA, Preuss D, Bureau T, Salzberg SL, Mewes HW. Sequence and analysis of the Arabidopsis genome. CURRENT OPINION IN PLANT BIOLOGY 2001; 4:105-110. [PMID: 11228431 DOI: 10.1016/s1369-5266(00)00144-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The comprehensive analysis of the genome sequence of the plant Arabidopsis thaliana has been completed recently. The genome sequence and associated analyses provide the foundations for rapid progress in many fields of plant research, such as the exploitation of genetic variation in Arabidopsis ecotypes, the assessment of the transcriptome and proteome, and the association of genome changes at the sequence level with evolutionary processes. Nevertheless, genome sequencing and analysis are only the first steps towards a new plant biology. Much remains to be done to refine the analysis of encoded genes, to define the functions of encoded proteins systematically, and to establish new generations of databases to capture and relate diverse data sets generated in widely distributed laboratories.
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Affiliation(s)
- M Bevan
- Molecular Genetics Department, John Innes Centre, Colney Lane, NR4 7UH, Norwich, UK.
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510
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Hong Z, Delauney AJ, Verma DP. A cell plate-specific callose synthase and its interaction with phragmoplastin. THE PLANT CELL 2001; 13:755-68. [PMID: 11283334 PMCID: PMC135532 DOI: 10.1105/tpc.13.4.755] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Callose is synthesized on the forming cell plate and several other locations in the plant. We cloned an Arabidopsis cDNA encoding a callose synthase (CalS1) catalytic subunit. The CalS1 gene comprises 42 exons with 41 introns and is transcribed into a 6.0-kb mRNA. The deduced peptide, with an approximate molecular mass of 226 kD, showed sequence homology with the yeast 1,3-beta-glucan synthases and is distinct from plant cellulose synthases. CalS1 contains 16 predicted transmembrane helices with the N-terminal region and a large central loop facing the cytoplasm. CalS1 interacts with two cell plate--associated proteins, phragmoplastin and a novel UDP-glucose transferase that copurifies with the CalS complex. That CalS1 is a cell plate--specific enzyme is demonstrated by the observations that the green fluorescent protein--CalS1 fusion protein was localized at the growing cell plate, that expression of CalS1 in transgenic tobacco cells enhanced callose synthesis on the forming cell plate, and that these cell lines exhibited higher levels of CalS activity. These data also suggest that plant CalS may form a complex with UDP-glucose transferase to facilitate the transfer of substrate for callose synthesis.
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Affiliation(s)
- Z Hong
- Department of Molecular Genetics and Plant Biotechnology Center, Ohio State University, 1060 Carmack Road, Columbus, Ohio 43210, USA
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511
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Ciaffi M, Paolacci AR, Dominici L, Tanzarella OA, Porceddu E. Molecular characterization of gene sequences coding for protein disulfide isomerase (PDI) in durum wheat (Triticum turgidum ssp. durum). Gene 2001; 265:147-56. [PMID: 11255017 DOI: 10.1016/s0378-1119(01)00348-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The organisation of the durum wheat genomic sequence (3.5 kb) coding for protein disulfide isomerase (PDI), deduced by comparison between genomic fragments and cDNA sequences (1.5 kb) isolated from immature caryopses, is described. The gene structure consists of ten exons and nine introns. The presence of consensus sequences involved in splicing, such as intron-exon junctions and branchpoint, has been observed and discussed. Although the deduced wheat PDI amino acid sequence exhibited an overall identity of only 31% to that of human PDI, their modular architecture in terms of number, size, location and secondary structure-propensities of the constituent domains are remarkably similar. The comparison of the amino acid sequences with the eight available plant PDI-like sequences showed a high identity with four of them and low with the remaining ones. Analyses of transcription levels showed that the PDI mRNA was present in all analysed tissues, with much higher expression in immature caryopses.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Blotting, Northern
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA, Plant/isolation & purification
- Exons
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant/genetics
- Introns
- Molecular Sequence Data
- Phylogeny
- Polymerase Chain Reaction
- Protein Disulfide-Isomerases/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
- Triticum/enzymology
- Triticum/genetics
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Affiliation(s)
- M Ciaffi
- Department of Agrobiology and Agrochemistry, University of Tuscia, 01100, Viterbo, Italy
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512
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Pertea M, Lin X, Salzberg SL. GeneSplicer: a new computational method for splice site prediction. Nucleic Acids Res 2001; 29:1185-90. [PMID: 11222768 PMCID: PMC29713 DOI: 10.1093/nar/29.5.1185] [Citation(s) in RCA: 403] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
GeneSplicer is a new, flexible system for detecting splice sites in the genomic DNA of various eukaryotes. The system has been tested successfully using DNA from two reference organisms: the model plant Arabidopsis thaliana and human. It was compared to six programs representing the leading splice site detectors for each of these species: NetPlantGene, NetGene2, HSPL, NNSplice, GENIO and SpliceView. In each case GeneSplicer performed comparably to the best alternative, in terms of both accuracy and computational efficiency.
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Affiliation(s)
- M Pertea
- The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850, USA
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513
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Quiros CF, Grellet F, Sadowski J, Suzuki T, Li G, Wroblewski T. Arabidopsis and Brassica comparative genomics: sequence, structure and gene content in the ABI-Rps2-Ck1 chromosomal segment and related regions. Genetics 2001; 157:1321-30. [PMID: 11238417 PMCID: PMC1461565 DOI: 10.1093/genetics/157.3.1321] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The region corresponding to the ABI1-Rps2-Ck1 segment on chromosome 4 of Arabidopsis thaliana was sequenced in Brassica oleracea. Similar to A. thaliana, the B. oleracea homolog BoRps2 is present in single copy. The B. oleracea orthologous segment was located on chromosome 4 and can be distinguished by the presence of an N-myristoyl transferase coding gene (N-myr) between the Rps2 and Ck1 (BoCk1a) genes. The N-myr homologs in Arabidopsis are on chromosomes 2 and 5. Additional homologs for Ck1 are located on these two chromosomes. A second Ck1 homolog found on B. oleracea (BoCk1b) chromosome 7 served to define another orthologous segment located in Arabidopsis chromosome 1. The two segments displayed identical gene content and order in both species, namely BoCK1b, a gene encoding a hypothetical protein (BohypothA) and transcription factor eiF4A. High levels of sequence identity were observed for the coding sequences of all genes examined. Although in general larger spacers were found in Brassica than in A. thaliana, this was not always the case. Promoters were poorly conserved, except for several sequence stretches of a few nucleotides. Comparative sequencing revealed microsyntenic changes resulting from chromosomal structural rearrangements, which are often undetectable by genetic mapping.
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Affiliation(s)
- C F Quiros
- Department of Vegetable Crops, University of California, Davis, California 95616, USA.
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514
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Abstract
The flowering plant Arabidopsis thaliana is an important model system for identifying genes and determining their functions. Here we report the analysis of the genomic sequence of Arabidopsis. The sequenced regions cover 115.4 megabases of the 125-megabase genome and extend into centromeric regions. The evolution of Arabidopsis involved a whole-genome duplication, followed by subsequent gene loss and extensive local gene duplications, giving rise to a dynamic genome enriched by lateral gene transfer from a cyanobacterial-like ancestor of the plastid. The genome contains 25,498 genes encoding proteins from 11,000 families, similar to the functional diversity of Drosophila and Caenorhabditis elegans--the other sequenced multicellular eukaryotes. Arabidopsis has many families of new proteins but also lacks several common protein families, indicating that the sets of common proteins have undergone differential expansion and contraction in the three multicellular eukaryotes. This is the first complete genome sequence of a plant and provides the foundations for more comprehensive comparison of conserved processes in all eukaryotes, identifying a wide range of plant-specific gene functions and establishing rapid systematic ways to identify genes for crop improvement.
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515
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Theologis A, Ecker JR, Palm CJ, Federspiel NA, Kaul S, White O, Alonso J, Altafi H, Araujo R, Bowman CL, Brooks SY, Buehler E, Chan A, Chao Q, Chen H, Cheuk RF, Chin CW, Chung MK, Conn L, Conway AB, Conway AR, Creasy TH, Dewar K, Dunn P, Etgu P, Feldblyum TV, Feng J, Fong B, Fujii CY, Gill JE, Goldsmith AD, Haas B, Hansen NF, Hughes B, Huizar L, Hunter JL, Jenkins J, Johnson-Hopson C, Khan S, Khaykin E, Kim CJ, Koo HL, Kremenetskaia I, Kurtz DB, Kwan A, Lam B, Langin-Hooper S, Lee A, Lee JM, Lenz CA, Li JH, Li Y, Lin X, Liu SX, Liu ZA, Luros JS, Maiti R, Marziali A, Militscher J, Miranda M, Nguyen M, Nierman WC, Osborne BI, Pai G, Peterson J, Pham PK, Rizzo M, Rooney T, Rowley D, Sakano H, Salzberg SL, Schwartz JR, Shinn P, Southwick AM, Sun H, Tallon LJ, Tambunga G, Toriumi MJ, Town CD, Utterback T, Van Aken S, Vaysberg M, Vysotskaia VS, Walker M, Wu D, Yu G, Fraser CM, Venter JC, Davis RW. Sequence and analysis of chromosome 1 of the plant Arabidopsis thaliana. Nature 2000; 408:816-20. [PMID: 11130712 DOI: 10.1038/35048500] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genome of the flowering plant Arabidopsis thaliana has five chromosomes. Here we report the sequence of the largest, chromosome 1, in two contigs of around 14.2 and 14.6 megabases. The contigs extend from the telomeres to the centromeric borders, regions rich in transposons, retrotransposons and repetitive elements such as the 180-base-pair repeat. The chromosome represents 25% of the genome and contains about 6,850 open reading frames, 236 transfer RNAs (tRNAs) and 12 small nuclear RNAs. There are two clusters of tRNA genes at different places on the chromosome. One consists of 27 tRNA(Pro) genes and the other contains 27 tandem repeats of tRNA(Tyr)-tRNA(Tyr)-tRNA(Ser) genes. Chromosome 1 contains about 300 gene families with clustered duplications. There are also many repeat elements, representing 8% of the sequence.
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Affiliation(s)
- A Theologis
- Plant Gene Expression Center/USDA-U.C. Berkley, Albany, California 94710, USA.
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516
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Tabata S, Kaneko T, Nakamura Y, Kotani H, Kato T, Asamizu E, Miyajima N, Sasamoto S, Kimura T, Hosouchi T, Kawashima K, Kohara M, Matsumoto M, Matsuno A, Muraki A, Nakayama S, Nakazaki N, Naruo K, Okumura S, Shinpo S, Takeuchi C, Wada T, Watanabe A, Yamada M, Yasuda M, Sato S, de la Bastide M, Huang E, Spiegel L, Gnoj L, O'Shaughnessy A, Preston R, Habermann K, Murray J, Johnson D, Rohlfing T, Nelson J, Stoneking T, Pepin K, Spieth J, Sekhon M, Armstrong J, Becker M, Belter E, Cordum H, Cordes M, Courtney L, Courtney W, Dante M, Du H, Edwards J, Fryman J, Haakensen B, Lamar E, Latreille P, Leonard S, Meyer R, Mulvaney E, Ozersky P, Riley A, Strowmatt C, Wagner-McPherson C, Wollam A, Yoakum M, Bell M, Dedhia N, Parnell L, Shah R, Rodriguez M, See LH, Vil D, Baker J, Kirchoff K, Toth K, King L, Bahret A, Miller B, Marra M, Martienssen R, McCombie WR, Wilson RK, Murphy G, Bancroft I, Volckaert G, Wambutt R, Düsterhöft A, Stiekema W, Pohl T, Entian KD, Terryn N, Hartley N, Bent E, Johnson S, Langham SA, McCullagh B, Robben J, Grymonprez B, Zimmermann W, Ramsperger U, Wedler H, Balke K, Wedler E, Peters S, van Staveren M, Dirkse W, Mooijman P, Lankhorst RK, Weitzenegger T, Bothe G, Rose M, Hauf J, Berneiser S, Hempel S, Feldpausch M, Lamberth S, Villarroel R, Gielen J, Ardiles W, Bents O, Lemcke K, Kolesov G, Mayer K, Rudd S, Schoof H, Schueller C, Zaccaria P, Mewes HW, Bevan M, Fransz P. Sequence and analysis of chromosome 5 of the plant Arabidopsis thaliana. Nature 2000; 408:823-6. [PMID: 11130714 DOI: 10.1038/35048507] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genome of the model plant Arabidopsis thaliana has been sequenced by an international collaboration, The Arabidopsis Genome Initiative. Here we report the complete sequence of chromosome 5. This chromosome is 26 megabases long; it is the second largest Arabidopsis chromosome and represents 21% of the sequenced regions of the genome. The sequence of chromosomes 2 and 4 have been reported previously and that of chromosomes 1 and 3, together with an analysis of the complete genome sequence, are reported in this issue. Analysis of the sequence of chromosome 5 yields further insights into centromere structure and the sequence determinants of heterochromatin condensation. The 5,874 genes encoded on chromosome 5 reveal several new functions in plants, and the patterns of gene organization provide insights into the mechanisms and extent of genome evolution in plants.
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Affiliation(s)
- S Tabata
- Kazusa DNA Research Institute, Kisarazu, Chiba, Japan
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517
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Giglione C, Serero A, Pierre M, Boisson B, Meinnel T. Identification of eukaryotic peptide deformylases reveals universality of N-terminal protein processing mechanisms. EMBO J 2000; 19:5916-29. [PMID: 11060042 PMCID: PMC305796 DOI: 10.1093/emboj/19.21.5916] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The N-terminal protein processing pathway is an essential mechanism found in all organisms. However, it is widely believed that deformylase, a key enzyme involved in this process in bacteria, does not exist in eukaryotes, thus making it a target for antibacterial agents such as actinonin. In an attempt to define this process in higher eukaryotes we have used Arabidopsis thaliana as a model organism. Two deformylase cDNAs, the first identified in any eukaryotic system, and six distinct methionine aminopeptidase cDNAs were cloned. The corresponding proteins were characterized in vivo and in vitro. Methionine aminopeptidases were found in the cytoplasm and in the organelles, while deformylases were localized in the organelles only. Our work shows that higher plants have a much more complex machinery for methionine removal than previously suspected. We were also able to identify deformylase homologues from several animals and clone the corresponding cDNA from human cells. Our data provide the first evidence that lower and higher eukaryotes, as well as bacteria, share a similar N-terminal protein processing machinery, indicating universality of this system.
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Affiliation(s)
- C Giglione
- Institut des Sciences Végétales, UPR40, Centre National de la Recherche Scientifique, Bâtiment 23, 1 avenue de la Terrasse, F-91198 Gif-sur-Yvette Cedex, France
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518
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Reinard T, Janke V, Willard J, Buck F, Jacobsen HJ, Vockley J. Cloning of a gene for an acyl-CoA dehydrogenase from Pisum sativum L. and purification and characterization of its product as an isovaleryl-CoA dehydrogenase. J Biol Chem 2000; 275:33738-43. [PMID: 10913142 DOI: 10.1074/jbc.m004178200] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Isovaleryl-CoA dehydrogenase (IVD, EC ) catalyzes the third step in the catabolism of leucine in mammals. Deficiency of this enzyme leads to the clinical disorder isovaleric acidemia. IVD has been purified and characterized from human and rat liver, and the x-ray crystallographic structure of purified recombinant human IVD has been reported. Nothing is known about IVD activity in plants, although cDNA clones from Arabidopsis thaliana and partial sequences from Gossypium hirsutum and Oryza sativa have been identified as putative IVDs based on sequence homology and immuno cross-reactivity. In this report we describe the identification and characterization of an IVD from pea, purification of the enzyme using a novel and rapid auxin affinity chromatography matrix, and cloning of the corresponding gene. At the amino acid level, pea IVD is 60% similar to human and rat IVD. The specific activity and abundance of plant IVD was found to be significantly lower than for its human counterpart and exhibits developmental regulation. Substrate specificity of the plant enzyme is similar to the human IVD, and it cross-reacts to anti-human IVD antibodies. Molecular modeling of the pea enzyme based on the structure of human IVD indicates a high degree of structural similarity among these enzymes. Glu-244, shown to function as the catalytic base in human IVD along with most of the amino acids that make up the acyl CoA binding pocket, is conserved in pea IVD. The genomic structure of the plant IVD gene consists of 13 exons and 12 introns, spanning approximately 4 kilobases, and the predicted RNA splicing sites exhibit the extended consensus sequence described for other plant genes.
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Affiliation(s)
- T Reinard
- LG Molekulargenetik, University of Hannover, Herrenhäuser Strasse, D-30419 Hannover, Federal Republic of Germany
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519
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Sullivan JA, Gray JC. The pea light-independent photomorphogenesis1 mutant results from partial duplication of COP1 generating an internal promoter and producing two distinct transcripts. THE PLANT CELL 2000; 12:1927-38. [PMID: 11041887 PMCID: PMC149130 DOI: 10.1105/tpc.12.10.1927] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2000] [Accepted: 07/17/2000] [Indexed: 05/19/2023]
Abstract
The pea lip1 (light-independent photomorphogenesis1) mutant shows many of the characteristics of light-grown development when grown in continuous darkness. To investigate the identity of LIP1, cDNAs encoding the pea homolog of COP1, a repressor of photomorphogenesis identified in Arabidopsis, were isolated from wild-type and lip1 pea seedlings. lip1 seedlings contained a wild-type COP1 transcript as well as a larger COP1' transcript that contained an internal in-frame duplication of 894 bp. The COP1' transcript segregated with the lip1 phenotype in F(2) seedlings and could be translated in vitro to produce a protein of approximately 100 kD. The COP1 gene in lip1 peas contained a 7.5-kb duplication, consisting of exons 1 to 7 of the wild-type sequence, located 2.5 kb upstream of a region of genomic DNA identical to the wild-type COP1 DNA sequence. Transcription and splicing of the mutant COP1 gene was predicted to produce the COP1' transcript, whereas transcription from an internal promoter in the 2.5-kb region of DNA located between the duplicated regions of COP1 would produce the wild-type COP1 transcript. The presence of small quantities of wild-type COP1 transcripts may reduce the severity of the phenotype produced by the mutated COP1' protein. The genomic DNA sequences of the COP1 gene from wild-type and lip1 peas and the cDNA sequences of COP1 and COP1' transcripts have been submitted to the EMBL database under the EMBL accession numbers AJ276591, AJ276592, AJ289773, and AJ289774, respectively.
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Affiliation(s)
- J A Sullivan
- Department of Plant Sciences and Cambridge Centre for Molecular Recognition, University of Cambridge, Downing Street, Cambridge, CB2 3EA, United Kingdom
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520
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Comai L, Tyagi AP, Winter K, Holmes-Davis R, Reynolds SH, Stevens Y, Byers B. Phenotypic instability and rapid gene silencing in newly formed arabidopsis allotetraploids. THE PLANT CELL 2000; 12:1551-68. [PMID: 11006331 PMCID: PMC149069 DOI: 10.1105/tpc.12.9.1551] [Citation(s) in RCA: 355] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2000] [Accepted: 06/28/2000] [Indexed: 05/18/2023]
Abstract
Allopolyploid hybridization serves as a major pathway for plant evolution, but in its early stages it is associated with phenotypic and genomic instabilities that are poorly understood. We have investigated allopolyploidization between Arabidopsis thaliana (2n = 2x = 10; n, gametic chromosome number; x, haploid chromosome number) and Cardaminopsis arenosa (2n = 4x = 32). The variable phenotype of the allotetraploids could not be explained by cytological abnormalities. However, we found suppression of 20 of the 700 genes examined by amplified fragment length polymorphism of cDNA. Independent reverse transcription-polymerase chain reaction analyses of 10 of these 20 genes confirmed silencing in three of them, suggesting that approximately 0.4% of the genes in the allotetraploids are silenced. These three silenced genes were characterized. One, called K7, is repeated and similar to transposons. Another is RAP2.1, a member of the large APETALA2 (AP2) gene family, and has a repeated element upstream of its 5' end. The last, L6, is an unknown gene close to ALCOHOL DEHYDROGENASE on chromosome 1. CNG DNA methylation of K7 was less in the allotetraploids than in the parents, and the element varied in copy number. That K7 could be reactivated suggests epigenetic regulation. L6 was methylated in the C. arenosa genome. The present evidence that gene silencing accompanies allopolyploidization opens new avenues to this area of research.
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Affiliation(s)
- L Comai
- Department of Botany, Box 355325, University of Washington, Seattle, Washington 98195, USA.
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521
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Casacuberta E, Puigdomènech P, Monfort A. Distribution of microsatellites in relation to coding sequences within the Arabidopsis thaliana genome. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2000; 157:97-104. [PMID: 10940473 DOI: 10.1016/s0168-9452(00)00271-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The distribution of repetitive sequences, or microsatellites, formed by either one or two base pairs and longer than eight units, has been studied in almost 1 Mb of the sequenced Arabidopsis thaliana genome. Except for those formed by only G and C residues, the repetitions are more abundant in the Arabidopsis genome than can be calculated from its nucleotide composition. They are distributed in proportions higher than expected in introns, and in the intergenic regions both proximal and distal to the coding sequences. In exons, only the TC/GA microsatellite seems to be particularly abundant. The AT/TA microsatellites produce more length variation between Arabidopsis ecotypes than the A/T repeated sequences. These two classes are more abundant per kilobase than coding sequences in the Arabidopsis genome. The results indicate not only that the presence of microsatellites is not an effect of random distribution of nucleotides, but that their resolution as molecular markers may be equivalent to the number of genes and also that they do not seem to be systematically linked to specific regulatory sequences proximal to genes.
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Affiliation(s)
- E Casacuberta
- Departament de Genètica Molecular, Institut de Biologia Molecular de Barcelona, CID-CSIC, Jordi Girona, 18, 08034, Barcelona, Spain
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522
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Sanders PM, Lee PY, Biesgen C, Boone JD, Beals TP, Weiler EW, Goldberg RB. The arabidopsis DELAYED DEHISCENCE1 gene encodes an enzyme in the jasmonic acid synthesis pathway. THE PLANT CELL 2000; 12:1041-61. [PMID: 10899973 PMCID: PMC149048 DOI: 10.1105/tpc.12.7.1041] [Citation(s) in RCA: 331] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2000] [Accepted: 05/19/2000] [Indexed: 05/17/2023]
Abstract
delayed dehiscence1 is an Arabidopsis T-DNA mutant in which anthers release pollen grains too late for pollination to occur. The delayed dehiscence1 defect is caused by a delay in the stomium degeneration program. The gene disrupted in delayed dehiscence1 encodes 12-oxophytodienoate reductase, an enzyme in the jasmonic acid biosynthesis pathway. We rescued the mutant phenotype by exogenous application of jasmonic acid and obtained seed set from previously male-sterile plants. In situ hybridization studies showed that during the early stages of floral development, DELAYED DEHISCENCE1 mRNA accumulated within all floral organs. Later, DELAYED DEHISCENCE1 mRNA accumulated specifically within the pistil, petals, and stamen filaments. DELAYED DEHISCENCE1 mRNA was not detected in the stomium and septum cells of the anther that are involved in pollen release. The T-DNA insertion in delayed dehiscence1 eliminated both DELAYED DEHISCENCE1 mRNA accumulation and 12-oxophytodienoate reductase activity. These experiments suggest that jasmonic acid signaling plays a role in controlling the time of anther dehiscence within the flower.
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Affiliation(s)
- P M Sanders
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles 90095-1606, USA
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523
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Sanders PM, Lee PY, Biesgen C, Boone JD, Beals TP, Weiler EW, Goldberg RB. The arabidopsis DELAYED DEHISCENCE1 gene encodes an enzyme in the jasmonic acid synthesis pathway. THE PLANT CELL 2000; 12:1041-1061. [PMID: 10899973 DOI: 10.2307/3871254] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
delayed dehiscence1 is an Arabidopsis T-DNA mutant in which anthers release pollen grains too late for pollination to occur. The delayed dehiscence1 defect is caused by a delay in the stomium degeneration program. The gene disrupted in delayed dehiscence1 encodes 12-oxophytodienoate reductase, an enzyme in the jasmonic acid biosynthesis pathway. We rescued the mutant phenotype by exogenous application of jasmonic acid and obtained seed set from previously male-sterile plants. In situ hybridization studies showed that during the early stages of floral development, DELAYED DEHISCENCE1 mRNA accumulated within all floral organs. Later, DELAYED DEHISCENCE1 mRNA accumulated specifically within the pistil, petals, and stamen filaments. DELAYED DEHISCENCE1 mRNA was not detected in the stomium and septum cells of the anther that are involved in pollen release. The T-DNA insertion in delayed dehiscence1 eliminated both DELAYED DEHISCENCE1 mRNA accumulation and 12-oxophytodienoate reductase activity. These experiments suggest that jasmonic acid signaling plays a role in controlling the time of anther dehiscence within the flower.
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Affiliation(s)
- P M Sanders
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles 90095-1606, USA
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524
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Hoppe R, Weimer M, Beck A, Breer H, Strotmann J. Sequence analyses of the olfactory receptor gene cluster mOR37 on mouse chromosome 4. Genomics 2000; 66:284-95. [PMID: 10873383 DOI: 10.1006/geno.2000.6205] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The olfactory receptor multigene family is organized in clusters spread throughout the genome. In the present study, we have sequenced two subregions of the mOR37 gene cluster on mouse chromosome 4. The resulting 100 kb of sequence revealed seven odorant receptor coding regions and one gene fragment. Sequence analyses reveal that the mOR37 gene cluster may represent a rather ancient cluster. The mOR37 genes exhibit a complex intron/exon structure, and some appear to be differentially spliced. All genes in the cluster share conserved sequence motifs 5' of their putative initial exons, which represent potential binding sites for transcription factors. The clustered organization and conserved sequence motifs suggest common expression control mechanisms for these genes.
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Affiliation(s)
- R Hoppe
- Institute of Physiology, University of Hohenheim, Garbenstrasse 30, Stuttgart, D-70593, Germany
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525
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Wittstock U, Halkier BA. Cytochrome P450 CYP79A2 from Arabidopsis thaliana L. Catalyzes the conversion of L-phenylalanine to phenylacetaldoxime in the biosynthesis of benzylglucosinolate. J Biol Chem 2000; 275:14659-66. [PMID: 10799553 DOI: 10.1074/jbc.275.19.14659] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glucosinolates are natural plant products gaining increasing interest as cancer-preventing agents and crop protectants. Similar to cyanogenic glucosides, glucosinolates are derived from amino acids and have aldoximes as intermediates. We report cloning and characterization of cytochrome P450 CYP79A2 involved in aldoxime formation in the glucosinolate-producing Arabidopsis thaliana L. The CYP79A2 cDNA was cloned by polymerase chain reaction, and CYP79A2 was functionally expressed in Escherichia coli. Characterization of the recombinant protein shows that CYP79A2 is an N-hydroxylase converting L-phenylalanine into phenylacetaldoxime, the precursor of benzylglucosinolate. Transgenic A. thaliana constitutively expressing CYP79A2 accumulate high levels of benzylglucosinolate. CYP79A2 expressed in E. coli has a K(m) of 6.7 micromol liter(-1) for L-phenylalanine. Neither L-tyrosine, L-tryptophan, L-methionine, nor DL-homophenylalanine are metabolized by CYP79A2, indicating that the enzyme has a narrow substrate specificity. CYP79A2 is the first enzyme shown to catalyze the conversion of an amino acid to the aldoxime in the biosynthesis of glucosinolates. Our data provide the first conclusive evidence that evolutionarily conserved cytochromes P450 catalyze this step common for the biosynthetic pathways of glucosinolates and cyanogenic glucosides. This strongly indicates that the biosynthesis of glucosinolates has evolved based on a cyanogenic predisposition.
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Affiliation(s)
- U Wittstock
- Plant Biochemistry Laboratory, Department of Plant Biology, and Center for Molecular Plant Physiology (PlaCe), The Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen, Denmark
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526
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Feschotte C, Mouchès C. Evidence that a family of miniature inverted-repeat transposable elements (MITEs) from the Arabidopsis thaliana genome has arisen from a pogo-like DNA transposon. Mol Biol Evol 2000; 17:730-7. [PMID: 10779533 DOI: 10.1093/oxfordjournals.molbev.a026351] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sequence similarities exist between terminal inverted repeats (TIRs) of some miniature inverted-repeat transposable element (MITE) families isolated from a wide range of organisms, including plants, insects, and humans, and TIRs of DNA transposons from the pogo family. We present here evidence that one of these MITE families, previously described for Arabidopsis thaliana, is derived from a larger element encoding a putative transposase. We have named this novel class II transposon Lemi1. We show that its putative product is related to transposases of the Tc1/mariner superfamily, being closer to the pogo family. A similar truncated element was found in a tomato DNA sequence, indicating an ancient origin and/or horizontal transfer for this family of elements. These results are reminiscent of those recently reported for the human genome, where other members of the pogo family, named Tiggers, are believed to be responsible for the generation of abundant MITE-like elements in an early primate ancestor. These results further suggest that some MITE families, which are highly reiterated in plant, insect, and human genomes, could have arisen from a similar mechanism, implicating pogo-like elements.
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Affiliation(s)
- C Feschotte
- Laboratoire Ecologie Moléculaire et Faculté Sciences et Techniques Côte-Basque, Université de Pau et des Pays de l'Adour, Pau, France
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527
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Williams LE, Pittman JK, Hall JL. Emerging mechanisms for heavy metal transport in plants. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1465:104-26. [PMID: 10748249 DOI: 10.1016/s0005-2736(00)00133-4] [Citation(s) in RCA: 267] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Heavy metal ions such as Cu(2+), Zn(2+), Mn(2+), Fe(2+), Ni(2+) and Co(2+) are essential micronutrients for plant metabolism but when present in excess, these, and non-essential metals such as Cd(2+), Hg(2+) and Pb(2+), can become extremely toxic. Thus mechanisms must exist to satisfy the requirements of cellular metabolism but also to protect cells from toxic effects. The mechanisms deployed in the acquisition of essential heavy metal micronutrients have not been clearly defined although a number of genes have now been identified which encode potential transporters. This review concentrates on three classes of membrane transporters that have been implicated in the transport of heavy metals in a variety of organisms and could serve such a role in plants: the heavy metal (CPx-type) ATPases, the natural resistance-associated macrophage protein (Nramp) family and members of the cation diffusion facilitator (CDF) family. We aim to give an overview of the main features of these transporters in plants in terms of structure, function and regulation drawing on information from studies in a wide variety of organisms.
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Affiliation(s)
- L E Williams
- University of Southampton, School of Biological Sciences, Bassett Crescent East, Southampton, UK.
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528
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Paquette SM, Bak S, Feyereisen R. Intron-exon organization and phylogeny in a large superfamily, the paralogous cytochrome P450 genes of Arabidopsis thaliana. DNA Cell Biol 2000; 19:307-17. [PMID: 10855798 DOI: 10.1089/10445490050021221] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The cytochrome P450 gene superfamily is represented by 80 genes in animal genomes and perhaps more than 300 genes in plant genomes. We analyzed about half of all Arabidopsis P450 genes, a very large dataset of truly paralogous genes. Sequence alignments were used to draw phylogenetic trees, and this information was compared with the intron-exon organization of each P450 gene. We found 60 unique intron positions, of which 37 were phase 0 introns. Our results confirm the polyphyletic origin of plant P450 genes. One group of these genes, the A-type P450s, are plant specific and characterized by a simple organization, with one highly conserved intron. Closely related A-type P450 genes are often clustered in the genome with as many as a dozen genes (e.g., of the CYP71 subfamily) on a short stretch of chromosome. The other P450 genes (non-A-type) form several distinct clades and are characterized by numerous introns. One such clade contains the two CYP51 genes, which are thought to encode obtusifoliol 14a demethylase. The two CYP51 genes have a single intron that is not shared with CYP51 genes from vertebrates or fungi, or with any other Arabidopsis P450 gene. Only a few of the Arabidopsis P450 genes are intronless (e.g., the CYP710A and CYP96A subfamilies). There was a relatively good correlation between intron conservation and phylogenetic relationships between members of the P450 subfamilies. Gene organization appears to be a useful tool in establishing the evolutionary relatedness of P450 genes, which may help in predictions of P450 function.
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Affiliation(s)
- S M Paquette
- Department of Entomology, University of Arizona, Tucson 85721-0036, USA
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529
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Usuka J, Brendel V. Gene structure prediction by spliced alignment of genomic DNA with protein sequences: increased accuracy by differential splice site scoring. J Mol Biol 2000; 297:1075-85. [PMID: 10764574 DOI: 10.1006/jmbi.2000.3641] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gene identification in genomic DNA from eukaryotes is complicated by the vast combinatorial possibilities of potential exon assemblies. If the gene encodes a protein that is closely related to known proteins, gene identification is aided by matching similarity of potential translation products to those target proteins. The genomic DNA and protein sequences can be aligned directly by scoring the implied residues of in-frame nucleotide triplets against the protein residues in conventional ways, while allowing for long gaps in the alignment corresponding to introns in the genomic DNA. We describe a novel method for such spliced alignment. The method derives an optimal alignment based on scoring for both sequence similarity of the predicted gene product to the protein sequence and intrinsic splice site strength of the predicted introns. Application of the method to a representative set of 50 known genes from Arabidopsis thaliana showed significant improvement in prediction accuracy compared to previous spliced alignment methods. The method is also more accurate than ab initio gene prediction methods, provided sufficiently close target proteins are available. In view of the fast growth of public sequence repositories, we argue that close targets will be available for the majority of novel genes, making spliced alignment an excellent practical tool for high-throughput automated genome annotation.
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Affiliation(s)
- J Usuka
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
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530
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Sasaki T, Burr B. International Rice Genome Sequencing Project: the effort to completely sequence the rice genome. CURRENT OPINION IN PLANT BIOLOGY 2000; 3:138-41. [PMID: 10712951 DOI: 10.1016/s1369-5266(99)00047-3] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The International Rice Genome Sequencing Project (IRGSP) involves researchers from ten countries who are working to completely and accurately sequence the rice genome within a short period. Sequencing uses a map-based clone-by-clone shotgun strategy; shared bacterial artificial chromosome/P1-derived artificial chromosome libraries have been constructed from Oryza sativa ssp. japonica variety 'Nipponbare'. End-sequencing, fingerprinting and marker-aided PCR screening are being used to make sequence-ready contigs. Annotated sequences are immediately released for public use and are made available with supplemental information at each IRGSP member's website. The IRGSP works to promote the development of rice and cereal genomics in addition to producing genome sequence data.
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Affiliation(s)
- T Sasaki
- Rice Genome Research Program, National Institute of Agrobiological Resources, Tsukuba, 305-8602, Japan.
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531
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Aubourg S, Boudet N, Kreis M, Lecharny A. In Arabidopsis thaliana, 1% of the genome codes for a novel protein family unique to plants. PLANT MOLECULAR BIOLOGY 2000; 42:603-13. [PMID: 10809006 DOI: 10.1023/a:1006352315928] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In the sequences released by the Arabidopsis Genome Initiative (AGI), we discovered a new and unexpectedly large family of orphan genes (127 genes by 01.08.99), named AtPCMP. The distribution of the AtPCMP genes on the five chromosomes suggests that the genome of Arabidopsis thaliana contains more than 200 genes of this family (1% of the whole genome). The deduced AtPCMP proteins are characterized by a surprising combinatorial organization of sequence motifs. The amino-terminal domain is made of a succession of three conserved motifs which generate an important diversity. These proteins are classified into three subfamilies based on the length and nature of their carboxy-terminal domain constituted by 1-6 motifs. All the motifs characterized have an important level of conservation in both sequence and spacing. A specific signature of this large family is defined. The presence of ESTs in databases and the detection of clones in A. thaliana cDNA libraries indicate that most of the genes of this family are expressed. The absence of similar sequences outside the plant kingdom strongly suggests that this unusually large orphan family is unique to plants. Features, the genesis, the potential function and the evolution of this plant combinatorial and modular protein family are discussed.
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Affiliation(s)
- S Aubourg
- Institut de Biotechnologie des Plantes, UMR CNRS 8618, Laboratoire de Biologie du Développement des Plantes, Université de Paris-Sud, Orsay, France
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532
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Tavares R, Aubourg S, Lecharny A, Kreis M. Organization and structural evolution of four multigene families in Arabidopsis thaliana: AtLCAD, AtLGT, AtMYST and AtHD-GL2. PLANT MOLECULAR BIOLOGY 2000; 42:703-717. [PMID: 10809443 DOI: 10.1023/a:1006368316413] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The Arabidopsis Genome Initiative has released up to now more than 80% of the genome sequence of Arabidopsis thaliana. About 70% of the identified genes have at least one paralogue. In order to understand the biological function of individual genes, it is essential to study the structure, expression and organization of the entire multigene family. A systematic analysis of multigene families, made possible by the amount of genomic sequence data available, provides important clues for the understanding of genome evolution and plasticity. In this paper, four multigene families of A. thaliana are characterized, namely LCAD, HD-GL2, LGT and MYST. Members of HD-GL2 and LCAD have already been reported in plants. The LGT genes specify proteins containing motifs of glycosyl transferase. No plant genes similar to the LGT genes have been reported to date. The novel MYST family, most likely plant-specific, encodes proteins with no identified function. Sequencing and in silico analysis led to the characterization of 29 novel genes belonging to these four gene families. The organization, structure and evolution of all the members of the four families are discussed, as well as their chromosome location. Expression data of some of the paralogues of each family are also presented.
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Affiliation(s)
- R Tavares
- Institut de Biotechnologie des Plantes, Laboratoire de Biologie du Développement des Plantes, Université de Paris-Sud, Orsay France
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533
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Kitahara K, Matsumoto S. Rose MADS-box genes 'MASAKO C1 and D1' homologous to class C floral identity genes. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2000; 151:121-134. [PMID: 10808068 DOI: 10.1016/s0168-9452(99)00206-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We isolated AGAMOUS-like cDNA clones called MASAKO C1-C6 (C4-C6 are 3' or 5' partial cDNA clones) and MASAKO D1 from wild rose (Rosa rugosa Thunb. ex Murray). We found that MASAKO C1 was a homologue of AGAMOUS on the basis of sequence similarity, conservation of intron positions, and stamen- and carpel-specific expression within reproductive organs. MASAKO C1-C6 seem to have arisen via alternative splicing, and a possible function of one of the different mRNAs 'MASAKO C6' is discussed in view of similarities between it and the ag-4 variant 2 within Arabidopsis thaliana. MASAKO D1 was also thought to be a homologue of AGAMOUS based on similarity of their sequences, and on the tissue specific expression pattern with GAG2, which is an AGAMOUS homologue in ginseng. Two types of AGAMOUS homologue genes are possibly present in wild rose, as has been observed in tobacco, petunia, cucumber, and maize.
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Affiliation(s)
- K Kitahara
- The United Graduate School of Agricultural Science, Gifu University, Gifu, Japan
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534
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535
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Cvrcková F. Are plant formins integral membrane proteins? Genome Biol 2000; 1:RESEARCH001. [PMID: 11104517 PMCID: PMC31918 DOI: 10.1186/gb-2000-1-1-research001] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/1999] [Revised: 01/25/2000] [Accepted: 01/28/2000] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The formin family of proteins has been implicated in signaling pathways of cellular morphogenesis in both animals and fungi; in the latter case, at least, they participate in communication between the actin cytoskeleton and the cell surface. Nevertheless, they appear to be cytoplasmic or nuclear proteins, and it is not clear whether they communicate with the plasma membrane, and if so, how. Because nothing is known about formin function in plants, I performed a systematic search for putative Arabidopsis thaliana formin homologs. RESULTS I found eight putative formin-coding genes in the publicly available part of the Arabidopsis genome sequence and analyzed their predicted protein sequences. Surprisingly, some of them lack parts of the conserved formin-homology 2 (FH2) domain and the majority of them seem to have signal sequences and putative transmembrane segments that are not found in yeast or animals formins. CONCLUSIONS Plant formins define a distinct subfamily. The presence in most Arabidopsis formins of sequence motifs typical or transmembrane proteins suggests a mechanism of membrane attachment that may be specific to plant formins, and indicates an unexpected evolutionary flexibility of the conserved formin domain.
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Affiliation(s)
- F Cvrcková
- Department of Plant Physiology, Faculty of Sciences, Charles University, Vinicná 5, CZ 128 44 Praha 2, Czech Republic.
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536
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Metz AM, Wong KC, Malmström SA, Browning KS. Eukaryotic initiation factor 4B from wheat and Arabidopsis thaliana is a member of a multigene family. Biochem Biophys Res Commun 1999; 266:314-21. [PMID: 10600500 DOI: 10.1006/bbrc.1999.1814] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Clones of eukaryotic initiation factor (eIF) 4B from wheat and Arabidopsis thaliana were obtained from cDNA and genomic libraries. The exon/intron organization of the genes from wheat and A. thaliana is very similar. The deduced amino acid sequences for the wheat and Arabidopsis eIF4B proteins showed overall similarity to each other, but very little similarity to eIF4B from other eukaryotes. The recombinant form of eIF4B supports polypeptide synthesis in an in vitro translation system and reacts with antibodies to native wheat eIF4B. In contrast to mammalian eIF4B and eIF4A, the combination of wheat eIF4B and eIF4A does not stimulate RNA-dependent ATP hydrolysis activity; however, wheat eIF4B does stimulate eIF4F and eIF4A RNA-dependent ATP hydrolysis activity. Interestingly, eIF4B does not stimulate eIF(iso)4F and eIF4A hydrolysis activity. Gel filtration experiments indicate wheat eIF4B, like its mammalian counterpart, self-associates to form a homodimer.
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Affiliation(s)
- A M Metz
- Department of Chemistry and Biochemistry and the Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712, USA
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537
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Lin X, Kaul S, Rounsley S, Shea TP, Benito MI, Town CD, Fujii CY, Mason T, Bowman CL, Barnstead M, Feldblyum TV, Buell CR, Ketchum KA, Lee J, Ronning CM, Koo HL, Moffat KS, Cronin LA, Shen M, Pai G, Van Aken S, Umayam L, Tallon LJ, Gill JE, Adams MD, Carrera AJ, Creasy TH, Goodman HM, Somerville CR, Copenhaver GP, Preuss D, Nierman WC, White O, Eisen JA, Salzberg SL, Fraser CM, Venter JC. Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana. Nature 1999; 402:761-8. [PMID: 10617197 DOI: 10.1038/45471] [Citation(s) in RCA: 417] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2.
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Affiliation(s)
- X Lin
- Institute for Genomic Research, Rockville, Maryland 20850, USA
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538
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Mayer K, Schüller C, Wambutt R, Murphy G, Volckaert G, Pohl T, Düsterhöft A, Stiekema W, Entian KD, Terryn N, Harris B, Ansorge W, Brandt P, Grivell L, Rieger M, Weichselgartner M, de Simone V, Obermaier B, Mache R, Müller M, Kreis M, Delseny M, Puigdomenech P, Watson M, Schmidtheini T, Reichert B, Portatelle D, Perez-Alonso M, Boutry M, Bancroft I, Vos P, Hoheisel J, Zimmermann W, Wedler H, Ridley P, Langham SA, McCullagh B, Bilham L, Robben J, Van der Schueren J, Grymonprez B, Chuang YJ, Vandenbussche F, Braeken M, Weltjens I, Voet M, Bastiaens I, Aert R, Defoor E, Weitzenegger T, Bothe G, Ramsperger U, Hilbert H, Braun M, Holzer E, Brandt A, Peters S, van Staveren M, Dirske W, Mooijman P, Klein Lankhorst R, Rose M, Hauf J, Kötter P, Berneiser S, Hempel S, Feldpausch M, Lamberth S, Van den Daele H, De Keyser A, Buysshaert C, Gielen J, Villarroel R, De Clercq R, Van Montagu M, Rogers J, Cronin A, Quail M, Bray-Allen S, Clark L, Doggett J, Hall S, Kay M, Lennard N, McLay K, Mayes R, Pettett A, Rajandream MA, Lyne M, Benes V, Rechmann S, Borkova D, Blöcker H, Scharfe M, Grimm M, Löhnert TH, Dose S, de Haan M, Maarse A, Schäfer M, Müller-Auer S, Gabel C, Fuchs M, Fartmann B, Granderath K, Dauner D, Herzl A, Neumann S, Argiriou A, Vitale D, Liguori R, Piravandi E, Massenet O, Quigley F, Clabauld G, Mündlein A, Felber R, Schnabl S, Hiller R, Schmidt W, Lecharny A, Aubourg S, Chefdor F, Cooke R, Berger C, Montfort A, Casacuberta E, Gibbons T, Weber N, Vandenbol M, Bargues M, Terol J, Torres A, Perez-Perez A, Purnelle B, Bent E, Johnson S, Tacon D, Jesse T, Heijnen L, Schwarz S, Scholler P, Heber S, Francs P, Bielke C, Frishman D, Haase D, Lemcke K, Mewes HW, Stocker S, Zaccaria P, Bevan M, Wilson RK, de la Bastide M, Habermann K, Parnell L, Dedhia N, Gnoj L, Schutz K, Huang E, Spiegel L, Sehkon M, Murray J, Sheet P, Cordes M, Abu-Threideh J, Stoneking T, Kalicki J, Graves T, Harmon G, Edwards J, Latreille P, Courtney L, Cloud J, Abbott A, Scott K, Johnson D, Minx P, Bentley D, Fulton B, Miller N, Greco T, Kemp K, Kramer J, Fulton L, Mardis E, Dante M, Pepin K, Hillier L, Nelson J, Spieth J, Ryan E, Andrews S, Geisel C, Layman D, Du H, Ali J, Berghoff A, Jones K, Drone K, Cotton M, Joshu C, Antonoiu B, Zidanic M, Strong C, Sun H, Lamar B, Yordan C, Ma P, Zhong J, Preston R, Vil D, Shekher M, Matero A, Shah R, Swaby IK, O'Shaughnessy A, Rodriguez M, Hoffmann J, Till S, Granat S, Shohdy N, Hasegawa A, Hameed A, Lodhi M, Johnson A, Chen E, Marra M, Martienssen R, McCombie WR. Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana. Nature 1999; 402:769-77. [PMID: 10617198 DOI: 10.1038/47134] [Citation(s) in RCA: 313] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The higher plant Arabidopsis thaliana (Arabidopsis) is an important model for identifying plant genes and determining their function. To assist biological investigations and to define chromosome structure, a coordinated effort to sequence the Arabidopsis genome was initiated in late 1996. Here we report one of the first milestones of this project, the sequence of chromosome 4. Analysis of 17.38 megabases of unique sequence, representing about 17% of the genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements. Heterochromatic regions surrounding the putative centromere, which has not yet been completely sequenced, are characterized by an increased frequency of a variety of repeats, new repeats, reduced recombination, lowered gene density and lowered gene expression. Roughly 60% of the predicted protein-coding genes have been functionally characterized on the basis of their homology to known genes. Many genes encode predicted proteins that are homologous to human and Caenorhabditis elegans proteins.
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Affiliation(s)
- K Mayer
- GSF-Forschungszentrum f. Umwelt u. Gesundheit, Munich Information Center for Protein Sequences am Max-Planck-Institut f. Biochemie, Germany
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539
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Gassmann W, Hinsch ME, Staskawicz BJ. The Arabidopsis RPS4 bacterial-resistance gene is a member of the TIR-NBS-LRR family of disease-resistance genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1999; 20:265-77. [PMID: 10571887 DOI: 10.1046/j.1365-313x.1999.t01-1-00600.x] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plant-disease resistance (R) genes mediate the specific recognition of invading pathogens carrying cognate avirulence (avr) determinants. RPS4 is a disease-resistance locus on chromosome 5 of Arabidopsis thaliana specifying resistance to strains of Pseudomonas syringae pv. tomato expressing avrRps4. We have isolated the RPS4 gene using a map-based cloning approach. RPS4 encodes a predicted protein of 1217 amino acids that contains an N-terminus with homology to the intracellular domains of the Drosophila Toll protein and the mammalian interleukin-1 receptor (TIR domain), a tripartite nucleotide-binding site (NBS), and leucine-rich repeats (LRR). Incomplete splicing of the RPS4 mRNA was observed, which may give rise to truncated protein products consisting mainly of the TIR and NBS domains. These features classify RPS4 as a member of the TIR-NBS-LRR R gene family founded by N, L6 and RPP5, which determine resistance to viral, fungal and oomycete pathogens, respectively. Previous work has shown that RPS4, like other Arabidopsis TIR-NBS-LRR R genes specifying resistance to oomycetes, is dependent on a functional EDS1 allele for disease-resistance signaling. The characterization of RPS4 presented here thus establishes a role for TIR-NBS-LRR R genes in resistance to bacterial pathogens, and provides evidence for the model that dependence of R genes on EDS1 is determined by R protein structure, and not by pathogen type. The cloning of RPS4 and the previous isolation of avrRps4 provide the molecular tools for a genetic and molecular dissection of the TIR-NBS-LRR R gene signaling pathway in Arabidopsis.
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Affiliation(s)
- W Gassmann
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
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540
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Sakamoto A, Tanaka A, Watanabe H, Tano S. Molecular cloning of Arabidopsis photolyase gene (PHR1) and characterization of its promoter region. DNA SEQUENCE : THE JOURNAL OF DNA SEQUENCING AND MAPPING 1999; 9:335-40. [PMID: 10524761 DOI: 10.3109/10425179809008473] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Photolyase is an enzyme that repairs ultraviolet (UV)-damaged DNA by photoreactivation. In higher plants, accumulation of photolyase (PHR1) mRNA is induced by either UV or visible light. In order to know the molecular mechanism by which PHR1 gene expression is induced by light, we have determined the genomic structure and the 5'-flanking sequence of the Arabidopsis PHR1 gene. The PHR1 gene spans approximately 2.5 kb of genomic DNA and consists of 9 exons. In the promoter region of PHR1, there are two pairs of inverted repeats spanning more than sixty base pairs. The promoter also contains DNA motifs similar to the GT-1 box or G-box found in many light-inducible gene promoters. EMSA analysis showed that several proteins in Arabidopsis nuclear extract bound to the G-box-like motifs. These results raise the possibility that the Arabidopsis PHR1 gene is regulated by transcription factors which interact with these motifs.
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Affiliation(s)
- A Sakamoto
- Research Group for Plant Genes, Advanced Science Research Center, Japan Atomic Energy Research Institute, Takasaki, Gunma.
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541
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Michalek W, Künzel G, Graner A. Sequence analysis and gene identification in a set of mapped RFLP markers in barley (Hordeum vulgare). Genome 1999; 42:849-53. [PMID: 10584307 DOI: 10.1139/g99-036] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The "Igri/Franka" (I/F) map ranks among the most comprehensive genetic linkage maps of barley (Hordeum vulgare), containing a large number of markers derived from cDNA and genomic PstI clones. Fourty-three cDNA clones and 259 genomic clones were at least partially sequenced and compared with the major data bases of protein and nucleic acid sequences. Of the cDNA clones, 53% show significant similarity to known sequences in protein data bases. A comparison of sequences from genomic clones to nucleic acid sequence data bases revealed similarities for 9% of the clones. For cDNA sequences analyzed the same way, significant similarities were observed for 35% of the clones. These results show that genomic PstI clones, although containing genes at a significant frequency, represent an inappropriate source for an efficient, systematic gene identification in barley. Sequence information obtained in the context of the present study provides a resource for the conversion of these markers into sequence-tagged site (STS) markers and their use in PCR assays.
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Affiliation(s)
- W Michalek
- Institute for Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
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542
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Bates PW, Vierstra RD. UPL1 and 2, two 405 kDa ubiquitin-protein ligases from Arabidopsis thaliana related to the HECT-domain protein family. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1999; 20:183-195. [PMID: 10571878 DOI: 10.1046/j.1365-313x.1999.00590.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The ubiquitin/26S proteasome pathway is a major route for degrading abnormal and important short-lived regulatory proteins in eukaryotes. Covalent attachment of ubiquitin, which triggers entry of target proteins into the pathway, is accomplished by an ATP-dependent reaction cascade involving the sequential action of three enzymes, E1s, E2s and E3s. Although much of the substrate specificity of the pathway is determined by E3s (or ubiquitin-protein ligases, UPLs), little is known about these enzymes in plants and how they choose appropriate targets for ubiquitination. Here, we describe two 405 kDa E3s (UPL1 and 2) from Arabidopsis thaliana related to the HECT-E3 family that is essential in yeast and animals. UPL1 and 2 are encoded by 13 kbp genes 26 cM apart on chromosome I, that are over 95% identical within both the introns and exons, suggesting that the two loci arose from a recent gene duplication. The C-terminal HECT domain of UPL1 is necessary and sufficient to conjugate ubiquitin in vitro in a reaction that requires the positionally conserved cysteine within the HECT domain, E1, and an E2 of the UBC8 family. Given that HECT E3s help define target specificity of the ubiquitin conjugation, a continued characterization of UPL1 and 2 should be instrumental in understanding the functions of ubiquitin-dependent protein turnover in plants and for identifying pathway substrates.
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Affiliation(s)
- P W Bates
- Cellular and Molecular Biology Program and Department of Horticulture, University of Wisconsin-Madison, 53706, USA
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543
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Abstract
Recent studies on the genomes of protists, plants, fungi and animals confirm that the increase in genome size and gene number in different eukaryotic lineages is paralleled by a general decrease in genome compactness and an increase in the number and size of introns. It may thus be predicted that exon-shuffling has become increasingly significant with the evolution of larger, less compact genomes. To test the validity of this prediction, we have analyzed the evolutionary distribution of modular proteins that have clearly evolved by intronic recombination. The results of this analysis indicate that modular multidomain proteins produced by exon-shuffling are restricted in their evolutionary distribution. Although such proteins are present in all major groups of metazoa from sponges to chordates, there is practically no evidence for the presence of related modular proteins in other groups of eukaryotes. The biological significance of this difference in the composition of the proteomes of animals, fungi, plants and protists is best appreciated when these modular proteins are classified with respect to their biological function. The majority of these proteins can be assigned to functional categories that are inextricably linked to multicellularity of animals, and are of absolute importance in permitting animals to function in an integrated fashion: constituents of the extracellular matrix, proteases involved in tissue remodelling processes, various proteins of body fluids, membrane-associated proteins mediating cell-cell and cell-matrix interactions, membrane associated receptor proteins regulating cell cell communications, etc. Although some basic types of modular proteins seem to be shared by all major groups of metazoa, there are also groups of modular proteins that appear to be restricted to certain evolutionary lineages. In summary, the results suggest that exon-shuffling acquired major significance at the time of metazoan radiation. It is interesting to note that the rise of exon-shuffling coincides with a spectacular burst of evolutionary creativity: the Big Bang of metazoan radiation. It seems probable that modular protein evolution by exon-shuffling has contributed significantly to this accelerated evolution of metazoa, since it facilitated the rapid construction of multidomain extracellular and cell surface proteins that are indispensable for multicellularity.
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Affiliation(s)
- L Patthy
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest.
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544
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Genschel U, Powell CA, Abell C, Smith AG. The final step of pantothenate biosynthesis in higher plants: cloning and characterization of pantothenate synthetase from Lotus japonicus and Oryza sativum (rice). Biochem J 1999; 341 ( Pt 3):669-78. [PMID: 10417331 PMCID: PMC1220405 DOI: 10.1042/0264-6021:3410669] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have isolated a Lotus japonicus cDNA for pantothenate (vitamin B(5)) synthetase (PS) by functional complementation of an Escherichia coli panC mutant (AT1371). A rice (Oryza sativum) expressed sequence tag, identified by sequence similarity to PS, was also able to complement the E. coli auxotroph, as was an open reading frame from Saccharomyces cerevisiae (baker's yeast). The Lotus and rice cDNAs encode proteins of approx. 34 kDa, which are 65% similar at the amino acid level and do not appear to encode N-terminal extensions by comparison with PS sequences from other organisms. Furthermore, analysis of genomic sequence flanking the coding sequence for PS in Lotus suggests the original cDNA is full-length. The Lotus and rice PSs are therefore likely to be cytosolic. Southern analysis of Lotus genomic DNA indicates that there is a single gene for PS. Recombinant PS from Lotus, overexpressed in E. coli AT1371, is a dimer. The enzyme requires d-pantoate, beta-alanine and ATP for activity and has a higher affinity for pantoate (K(m) 45 microM) than for beta-alanine (K(m) 990 microM). Uncompetitive substrate inhibition becomes significant at pantoate concentrations above 1 mM. The enzyme displays optimal activity at about 0.5 mM pantoate (k(cat) 0.63 s(-1)) and at pH 7.8. Neither oxopantoate nor pantoyl-lactone can replace pantoate as substrate. Antibodies raised against recombinant PS detected a band of 34 kDa in Western blots of Lotus proteins from both roots and leaves. The implications of these findings for pantothenate biosynthesis in plants are discussed.
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Affiliation(s)
- U Genschel
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, U.K
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545
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Leiter H, Mucha J, Staudacher E, Grimm R, Glössl J, Altmann F. Purification, cDNA cloning, and expression of GDP-L-Fuc:Asn-linked GlcNAc alpha1,3-fucosyltransferase from mung beans. J Biol Chem 1999; 274:21830-9. [PMID: 10419500 DOI: 10.1074/jbc.274.31.21830] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Substitution of the asparagine-linked GlcNAc by alpha1,3-linked fucose is a widespread feature of plant as well as of insect glycoproteins, which renders the N-glycan immunogenic. We have purified from mung bean seedlings the GDP-L-Fuc:Asn-linked GlcNAc alpha1,3-fucosyltransferase (core alpha1,3-fucosyltransferase) that is responsible for the synthesis of this linkage. The major isoform had an apparent mass of 54 kDa and isoelectric points ranging from 6. 8 to 8.2. From that protein, four tryptic peptides were isolated and sequenced. Based on an approach involving reverse transcriptase-polymerase chain reaction with degenerate primers and rapid amplification of cDNA ends, core alpha1,3-fucosyltransferase cDNA was cloned from mung bean mRNA. The 2200-base pair cDNA contained an open reading frame of 1530 base pairs that encoded a 510-amino acid protein with a predicted molecular mass of 56.8 kDa. Analysis of cDNA derived from genomic DNA revealed the presence of three introns within the open reading frame. Remarkably, from the four exons, only exon II exhibited significant homology to animal and bacterial alpha1,3/4-fucosyltransferases which, though, are responsible for the biosynthesis of Lewis determinants. The recombinant fucosyltransferase was expressed in Sf21 insect cells using a baculovirus vector. The enzyme acted on glycopeptides having the glycan structures GlcNAcbeta1-2Manalpha1-3(GlcNAcbeta1-2Manalpha1- 6)Manbeta1-4GlcNAcbet a1-4GlcNAcbeta1-Asn, GlcNAcbeta1-2Manalpha1-3(GlcNAcbeta1-2Manalpha1- 6)Manbeta1-4GlcNAcbet a1-4(Fucalpha1-6)GlcNAcbeta1-Asn, and GlcNAcbeta1-2Manalpha1-3[Manalpha1-3(Manalpha1-6 )Manalpha1-6]Manbeta1 -4GlcNAcbeta1-4GlcNAcbeta1-Asn but not on, e.g. N-acetyllactosamine. The structure of the core alpha1,3-fucosylated product was verified by high performance liquid chromatography of the pyridylaminated glycan and by its insensitivity to N-glycosidase F as revealed by matrix-assisted laser desorption/ionization time of flight mass spectrometry.
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Affiliation(s)
- H Leiter
- Institute of Chemistry, Universität für Bodenkultur, Muthgasse 18, 1190 Wien, Austria.
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546
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Walker AR, Davison PA, Bolognesi-Winfield AC, James CM, Srinivasan N, Blundell TL, Esch JJ, Marks MD, Gray JC. The TRANSPARENT TESTA GLABRA1 locus, which regulates trichome differentiation and anthocyanin biosynthesis in Arabidopsis, encodes a WD40 repeat protein. THE PLANT CELL 1999; 11:1337-50. [PMID: 10402433 PMCID: PMC144274 DOI: 10.1105/tpc.11.7.1337] [Citation(s) in RCA: 660] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The TRANSPARENT TESTA GLABRA1 (TTG1) locus regulates several developmental and biochemical pathways in Arabidopsis, including the formation of hairs on leaves, stems, and roots, and the production of seed mucilage and anthocyanin pigments. The TTG1 locus has been isolated by positional cloning, and its identity was confirmed by complementation of a ttg1 mutant. The locus encodes a protein of 341 amino acid residues with four WD40 repeats. The protein is similar to AN11, a regulator of anthocyanin biosynthesis in petunia, and more distantly related to those of the beta subunits of heterotrimeric G proteins, which suggests a role for TTG1 in signal transduction to downstream transcription factors. The 1.5-kb TTG1 transcript is present in all major organs of Arabidopsis. Sequence analysis of six mutant alleles has identified base changes producing truncations or single amino acid changes in the TTG1 protein.
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Affiliation(s)
- A R Walker
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, United Kingdom.
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547
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Fourgoux-Nicol A, Drouaud J, Haouazine N, Pelletier G, Guerche P. Isolation of rapeseed genes expressed early and specifically during development of the male gametophyte. PLANT MOLECULAR BIOLOGY 1999; 40:857-872. [PMID: 10487220 DOI: 10.1023/a:1006282507095] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A cDNA subtraction and differential hybridization strategy was used to isolate cDNAs expressed early during male gametophyte development in the important crop species Brassica napus. Three cDNAs, corresponding to genes highly and specifically expressed at the tetrad and microspore stages, are presented here. The analysis of one of them, named BnM3.4, by in situ hybridization, showed that it is expressed specifically and at a high level in the rapeseed microspore. The specificity in its profile of expression is most likely transcriptionally controlled as a similar pattern of expression was also observed in Arabidopsis thaliana plants transformed by the BnM3.4 promoter fused to the reporter GUS-coding sequence. The putative BnM3.4 promoter contains three dispersed copies of a motif described previously in the promoters of several genes expressed in the male gametophyte. The BnM3.4 gene encodes a predicted novel proline-rich protein of 23.4 kDa which may interact with cytoskeletal components or have a structural role in the cell wall.
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Affiliation(s)
- A Fourgoux-Nicol
- Station de Génétique et d'Amélioration des Plantes, Institut National de la Recherche Agronomique, Versailles, France
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548
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Walker AR, Davison PA, Bolognesi-Winfield AC, James CM, Srinivasan N, Blundell TL, Esch JJ, Marks MD, Gray JC. The TRANSPARENT TESTA GLABRA1 locus, which regulates trichome differentiation and anthocyanin biosynthesis in Arabidopsis, encodes a WD40 repeat protein. THE PLANT CELL 1999; 11:1337-1350. [PMID: 10402433 DOI: 10.2307/3870753] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The TRANSPARENT TESTA GLABRA1 (TTG1) locus regulates several developmental and biochemical pathways in Arabidopsis, including the formation of hairs on leaves, stems, and roots, and the production of seed mucilage and anthocyanin pigments. The TTG1 locus has been isolated by positional cloning, and its identity was confirmed by complementation of a ttg1 mutant. The locus encodes a protein of 341 amino acid residues with four WD40 repeats. The protein is similar to AN11, a regulator of anthocyanin biosynthesis in petunia, and more distantly related to those of the beta subunits of heterotrimeric G proteins, which suggests a role for TTG1 in signal transduction to downstream transcription factors. The 1.5-kb TTG1 transcript is present in all major organs of Arabidopsis. Sequence analysis of six mutant alleles has identified base changes producing truncations or single amino acid changes in the TTG1 protein.
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Affiliation(s)
- A R Walker
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, United Kingdom.
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549
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Vignal L, Lisacek F, Quinqueton J, d'Aubenton-Carafa Y, Thermes C. A multi-agent system simulating human splice site recognition. COMPUTERS & CHEMISTRY 1999; 23:219-31. [PMID: 10404617 DOI: 10.1016/s0097-8485(99)00019-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The present paper describes a method detecting splice sites automatically on the basis of sequence data and models of site/signal recognition supported by experimental evidences. The method is designed to simulate splicing and while doing so, track prediction failures, missing information and possibly test correcting hypotheses. Correlations between nucleotides in the splice site regions and the various elements of the acceptor region are evaluated and combined to assess compensating interactions between elements of the splicing machinery. A scanning model of the acceptor region and a model of interaction between the splicing complexes (exon definition model) are also incorporated in the detection process. Subsets of sites presenting deficiencies of several splice site elements could be identified. Further examination of these sites helps to determine lacking elements and refine models.
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550
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Jouannic S, Hamal A, Leprince AS, Tregear JW, Kreis M, Henry Y. Plant MAP kinase kinase kinases structure, classification and evolution. Gene X 1999; 233:1-11. [PMID: 10375615 DOI: 10.1016/s0378-1119(99)00152-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
The increasing number of reports describing plant MAP kinase signalling components reflects the cardinal role that MAP kinase pathways are likely to play during plant growth and development. Relationship and structural analyses of plant MAP kinase kinase kinase related cDNAs and genes established, on one hand, the PMEKKs, which may be distinguished into the alpha, beta, gamma, and zeta groups, and, on the other hand, the PRAFs that consist of the delta, eta and theta groups. Plant MAP3Ks are characterized by different primary structures, but conserved within a single group. A relationship analysis, which included animal, fungal and plant MAP3Ks, revealed a high degree of diversity among this biochemically established set of proteins, thus suggesting a range of biological functions. Four major families emerged, namely the MEKK/STE11, including the PMEKKs, the RAF, including the PRAFs, as well as the MLK and CDC7 families. These four families showed phylum-dependent distributions. Signature sequences characterizing the RAF family and the RAF subfamilies have been evidenced. However, no equivalent sequence motifs were identified for the MEKK/STE11 family, which is highly heterogeneous.
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Affiliation(s)
- S Jouannic
- Institut de Biotechnologie des Plantes (IBP), Laboratoire de Biologie du Développement des Plantes, Bâtiment 630, UMR 6818, Université de Paris-Sud, F-91405, Orsay Cedex, France
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