Tonoplast-localized OsMOT1;2 participates in interorgan molybdate distribution in rice

2021 ◽  
Author(s):  
Authors: Satoru Ishikawa ◽  
Shimpei Hayashi ◽  
Hachidai Tanikawa ◽  
Manaka Iino ◽  
Tadashi Abe ◽  
...  
Keyword(s):  
Reductase Activity ◽  
Sequence Similarity ◽  
Essential Element ◽  
Molecular Transport ◽  
Vacuolar Membrane ◽  
Amino Acid Sequence Similarity ◽  
Wild Type ◽  
Rice Mutant ◽  
Aerial Parts ◽  
Complete Deletion

Abstract Molybdenum (Mo) is an essential element for plant growth and is utilized by several key enzymes in biological redox processes. Rice assimilates molybdate ions via OsMOT1;1, a transporter with a high affinity for molybdate. However, other systems involved in the molecular transport of molybdate in rice remain unclear. Here, we characterized OsMOT1;2, which shares amino acid sequence similarity with AtMOT1;2 and functions in vacuolar molybdate export. We isolated a rice mutant harboring a complete deletion of OsMOT1;2. This mutant exhibited a significantly lower grain Mo concentration than the wild type (WT), but its growth was not inhibited. The Mo concentration in grains was restored by the introduction of WT OsMOT1;2. The OsMOT1;2-GFP protein was localized to the vacuolar membrane when transiently expressed in rice protoplasts. At the reproductive growth stage of the WT plant, OsMOT1;2 was highly expressed in the 2nd and lower leaf blades and nodes. The deletion of OsMOT1;2 impaired interorgan Mo allocation in aerial parts: relative to the WT, the mutant exhibited decreased Mo levels in the 1st and 2nd leaf blades and grains but increased Mo levels in the 2nd and lower leaf sheaths, nodes, and internodes. When the seedlings were exposed to a solution with a high KNO3 concentration in the absence of Mo, the mutant exhibited significantly lower nitrate reductase activity in the shoots than the WT. Our results suggest that OsMOT1;2 plays an essential role in interorgan Mo distribution and molybdoenzyme activity in rice.

scholarly journals Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

2021 ◽  
Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Transgenic Tobacco ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

scholarly journals Novel Developmental Genes, fruCD, of Myxococcus xanthus: Involvement of a Cell Division Protein in Multicellular Development

2003 ◽  
Vol 185 (11) ◽  
pp. 3317-3324 ◽  
Author(s):  
Takuya Akiyama ◽  
Sumiko Inouye ◽  
Teruya Komano
Keyword(s):  
Vegetative Growth ◽  
Transcription Initiation ◽  
Growth And Development ◽  
Sequence Similarity ◽  
Myxococcus Xanthus ◽  
Spore Formation ◽  
Amino Acid Sequence Similarity ◽  
Wild Type ◽  
Developmental Genes ◽  
Multicellular Development

ABSTRACT Myxococcus xanthus is a gram-negative soil bacterium that undergoes multicellular development upon nutrient starvation. In the present study, two novel developmental genes, fruC and fruD, of M. xanthus were identified and characterized. The FruD protein has significant amino acid sequence similarity to the DivIVA proteins of many bacteria including Bacillus subtilis. Vegetative cells of the fruD mutant exhibited a filamentous phenotype. The fruC and fruD mutants displayed similar delayed-development phenotypes. The formation of tightly aggregated mounds by fruC and fruD mutants was slower than that by the wild-type strain. Spore formation by the fruC and fruD mutants initiated after 30 h poststarvation, whereas wild-type M. xanthus initiated spore formation after 18 h. The fruCD genes were constitutively expressed as an operon during vegetative growth and development. S1 mapping revealed that transcription initiation sites of the fruCD operon were located 114 (P1) and 55 bp (P2) upstream of the fruC initiation codon. Only the P1 promoter was active during vegetative growth, while both the P1 and P2 promoters were active during development. The FruD protein was produced as a cytoplasmic protein and formed an oligomer during vegetative growth and development.

scholarly journals Glucosinolate Distribution in the Aerial Parts of sel1-10, a Disruption Mutant of the Sulfate Transporter SULTR1;2, in Mature Arabidopsis thaliana Plants

Plants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 95 ◽  
Author(s):  
Tomomi Morikawa-Ichinose ◽  
Sun-Ju Kim ◽  
Alaa Allahham ◽  
Ryota Kawaguchi ◽  
Akiko Maruyama-Nakashita
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Defense ◽  
Essential Element ◽  
Wild Type ◽  
Sulfur Deficiency ◽  
Sulfate Transporter ◽  
Disruption Mutant ◽  
Aerial Parts ◽  
Long Day ◽  
Different Parts

Plants take up sulfur (S), an essential element for all organisms, as sulfate, which is mainly attributed to the function of SULTR1;2 in Arabidopsis. A disruption mutant of SULTR1;2, sel1-10, has been characterized with phenotypes similar to plants grown under sulfur deficiency (−S). Although the effects of −S on S metabolism were well investigated in seedlings, no studies have been performed on mature Arabidopsis plants. To study further the effects of −S on S metabolism, we analyzed the accumulation and distribution of S-containing compounds in different parts of mature sel1-10 and of the wild-type (WT) plants grown under long-day conditions. While the levels of sulfate, cysteine, and glutathione were almost similar between sel1-10 and WT, levels of glucosinolates (GSLs) differed between them depending on the parts of the plant. GSLs levels in the leaves and stems were generally lower in sel1-10 than those in WT. However, sel1-10 seeds maintained similar levels of aliphatic GSLs to those in WT plants. GSL accumulation in reproductive tissues is likely to be prioritized even when sulfate supply is limited in sel1-10 for its role in S storage and plant defense.

scholarly journals Three New NifA-Regulated Genes in the Bradyrhizobium japonicum Symbiotic Gene Region Discovered by Competitive DNA-RNA Hybridization

2000 ◽  
Vol 182 (6) ◽  
pp. 1472-1480 ◽  
Author(s):  
Andrea Nienaber ◽  
Alexander Huber ◽  
Michael Göttfert ◽  
Hauke Hennecke ◽  
Hans-Martin Fischer
Keyword(s):  
Nitrogen Fixation ◽  
Bradyrhizobium Japonicum ◽  
Sequence Similarity ◽  
Regulatory Protein ◽  
Gene Clusters ◽  
Amino Acid Sequence Similarity ◽  
Wild Type ◽  
Significant Similarity ◽  
Symbiotic Gene

ABSTRACT The so-called symbiotic region of the Bradyrhizobium japonicum chromosome (C. Kündig, H. Hennecke, and M. Göttfert, J. Bacteriol. 175:613–622, 1993) was screened for the presence of genes controlled by the nitrogen fixation regulatory protein NifA. Southern blots of restriction enzyme-digested cosmids that represent an ordered, overlapping library of the symbiotic region were competitively hybridized with in vitro-labeled RNA from anaerobically grown wild-type cells and an excess of RNA isolated either from anaerobically grown nifA and rpoNmutant cells or from aerobically grown wild-type cells. In addition to the previously characterized nif and fixgene clusters, we identified three new NifA-regulated genes that were named nrgA, nrgB, and nrgC(nrg stands for NifA-regulated gene). The latter two probably form an operon, nrgBC. The proteins encoded bynrgC and nrgA exhibited amino acid sequence similarity to bacterial hydroxylases andN-acetyltransferases, respectively. The product ofnrgB showed no significant similarity to any protein with a database entry. Primer extension experiments and expression studies with translational lacZ fusions revealed the presence of a functional −24/−12-type promoter upstream ofnrgA and nrgBC and proved the NifA- and RpoN (ς54)-dependent transcription of the respective genes. Null mutations introduced into nrgA and nrgBCresulted in mutant strains that exhibited wild-type-like symbiotic properties, including nitrogen fixation, when tested on soybean, cowpea, or mung bean host plants. Thus, the discovery ofnrgA and nrgBC further emphasizes the previously suggested role of NifA as an activator of anaerobically induced genes other than the classical nitrogen fixation genes.

scholarly journals Interaction between mismatch repair and genetic recombination in Saccharomyces cerevisiae.

Genetics ◽  
1994 ◽  
Vol 137 (1) ◽  
pp. 19-39 ◽  
Author(s):  
E Alani ◽  
R A Reenan ◽  
R D Kolodner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Mismatch Repair ◽  
Base Pair ◽  
Genetic Recombination ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Heteroduplex Dna

Abstract The yeast Saccharomyces cerevisiae encodes a set of genes that show strong amino acid sequence similarity to MutS and MutL, proteins required for mismatch repair in Escherichia coli. We examined the role of MSH2 and PMS1, yeast homologs of mutS and mutL, respectively, in the repair of base pair mismatches formed during meiotic recombination. By using specifically marked HIS4 and ARG4 alleles, we showed that msh2 mutants displayed a severe defect in the repair of all base pair mismatches as well as 1-, 2- and 4-bp insertion/deletion mispairs. The msh2 and pms1 phenotypes were indistinguishable, suggesting that the wild-type gene products act in the same repair pathway. A comparison of gene conversion events in wild-type and msh2 mutants indicated that mismatch repair plays an important role in genetic recombination. (1) Tetrad analysis at five different loci revealed that, in msh2 mutants, the majority of aberrant segregants displayed a sectored phenotype, consistent with a failure to repair mismatches created during heteroduplex formation. In wild type, base pair mismatches were almost exclusively repaired toward conversion rather than restoration. (2) In msh2 strains 10-19% of the aberrant tetrads were Ab4:4. (3) Polarity gradients at HIS4 and ARG4 were nearly abolished in msh2 mutants. The frequency of gene conversion at the 3' end of these genes was increased and was nearly the frequency observed at the 5' end. (4) Co-conversion studies were consistent with mismatch repair acting to regulate heteroduplex DNA tract length. We favor a model proposing that recombination events occur through the formation and resolution of heteroduplex intermediates and that mismatch repair proteins specifically interact with recombination enzymes to regulate the length of symmetric heteroduplex DNA.

scholarly journals A dominant negative inhibitor indicates that monocyte chemoattractant protein 1 functions as a dimer.

1995 ◽  
Vol 15 (9) ◽  
pp. 4851-4855 ◽  
Author(s):  
Y Zhang ◽  
B J Rollins
Keyword(s):  
Sequence Similarity ◽  
Effective Concentration ◽  
Dominant Negative ◽  
Amino Acid Sequence Similarity ◽  
Wild Type ◽  
Aberrant Expression ◽  
Monocyte Chemoattractant Protein 1 ◽  
Monocyte Chemoattractant ◽  
Monocyte Chemoattractant Protein ◽  
Dominant Negative Inhibitor

Monocyte chemoattractant protein 1 (MCP-1) is a member of the chemokine family of proinflammatory cytokines, all of which share a high degree of amino acid sequence similarity. Aberrant expression of chemokines occurs in a variety of diseases that have an inflammatory component, such as atherosclerosis. Although structural analyses indicate that chemokines form homodimers, there is controversy about whether dimerization is necessary for activity. To address this question for MCP-1, we obtained evidence in four steps. First, coprecipitation experiments demonstrated that MCP-1 forms dimers at physiological concentrations. Second, chemically cross-linked MCP-1 dimers attract monocytes in vitro with a 50% effective concentration of 400 pM, identical to the activity of non-cross-linked MCP-1. Third, an N-terminal deletion variant of MCP-1 (called 7ND) that inhibits MCP-1-mediated monocyte chemotaxis specifically forms heterodimers with wild-type MCP-1. Finally, although 7ND inhibits wild-type MCP-1 activity, it has no effect on cross-linked MCP-1. These results indicate that 7ND is a dominant negative inhibitor, implying that MCP-1 activates its receptor as a dimer. In addition, chemical cross-linking restores activity to an inactive N-terminal insertional variant of MCP-1, further supporting the need for dimerization. Since the reported Kd for MCP-1 monomer dissociation is much higher than its 50% effective concentration or Kd for receptor binding, active dimer formation may require high local concentrations of MCP-1. Our data further suggest that the dimer interface can be a target for MCP-1 inhibitory drugs.

Molecular and genetic characterization of natural variants of HIV-1 Nef gene from North India and its functional implication in down-regulation of MHC-I and CD-4

2020 ◽  
Vol 18 ◽  
Author(s):  
J. Singh ◽  
L. Ronsard ◽  
M. Pandey ◽  
R. Kapoor ◽  
V.G. Ramachandran ◽  
...  
Keyword(s):  
Biological Activities ◽  
Sequence Similarity ◽  
Eukaryotic Expression ◽  
North India ◽  
Cell Surface Expression ◽  
Functional Domains ◽  
Wild Type ◽  
Down Regulation ◽  
Subtype B ◽  
Hiv 1

Background: HIV-1 Nef is an important accessory protein with multiple effector functions. Genetic studies of HIV-1 Nef gene shows extensive genetic diversity and the functional studies have been carried out mostly with Nef derived from regions dominated by subtype B (North America & Europe). Objective: This study was carried out to characterize genetic variations of the Nef gene from HIV-1 infected individuals from North-India and to find out their functional implications. Methods: The unique representative variants were sub-cloned in eukaryotic expression vector and further characterized with respect to their ability to down regulate cell surface expression of CD4 and MHC-1molecules. Results: The phylogenetic analysis of Nef variants revealed sequence similarity with either consensus subtype B or B/C recombinants. Boot scan analysis of some of our variants showed homology to B/C recombinant and some to wild type Nef B. Extensive variations were observed in most of the variants. The dN/dS ratio revealed 80% purifying selection and 20% diversifying selection implying the importance of mutations in Nef variants. Intracellular stability of Nef variants differed greatly when compared with wild type Nef B and C. There were some variants that possessed mutations in the functional domains of Nef and responsible for its differential CD4 and MHC-1 down regulation activity. Conclusion: We observed enhanced biological activities in some of the variants, perhaps arising out of amino acid substitutions in their functional domains. The CD4 and MHC-1 down-regulation activity of Nef is likely to confer immense survival advantage allowing the most rare genotype in a population to become the most abundant after a single selection event.

scholarly journals Klebsiella Phage ΦK64-1 Encodes Multiple Depolymerases for Multiple Host Capsular Types

2017 ◽  
Vol 91 (6) ◽  
Author(s):  
Yi-Jiun Pan ◽  
Tzu-Lung Lin ◽  
Ching-Ching Chen ◽  
Yun-Ting Tsai ◽  
Yi-Hsiang Cheng ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Gene Products ◽  
Capsular Type ◽  
Expression And Purification ◽  
Content Type ◽  
Infection Mechanisms ◽  
Host Infection ◽  
Encoding Genes ◽  
Tail Fibers

ABSTRACT The genome of the multihost bacteriophage ΦK64-1, capable of infecting Klebsiella capsular types K1, K11, K21, K25, K30, K35, K64, and K69, as well as new capsular types KN4 and KN5, was analyzed and revealed that 11 genes (S1-1, S1-2, S1-3, S2-1, S2-2, S2-3, S2-4, S2-5, S2-6, S2-7, and S2-8) encode proteins with amino acid sequence similarity to tail fibers/spikes or lyases. S2-5 previously was shown to encode a K64 capsule depolymerase (K64dep). Specific capsule-degrading activities of an additional eight putative capsule depolymerases (S2-4 against K1, S1-1 against K11, S1-3 against K21, S2-2 against K25, S2-6 against K30/K69, S2-3 against K35, S1-2 against KN4, and S2-1 against KN5) was demonstrated by expression and purification of the recombinant proteins. Consistent with the capsular type-specific depolymerization activity of these gene products, phage mutants of S1-2, S2-2, S2-3, or S2-6 lost infectivity for KN4, K25, K35, or K30/K69, respectively, indicating that capsule depolymerase is crucial for infecting specific hosts. In conclusion, we identified nine functional capsule depolymerase-encoding genes in a bacteriophage and correlated activities of the gene products to all ten hosts of this phage, providing an example of type-specific host infection mechanisms in a multihost bacteriophage. IMPORTANCE We currently identified eight novel capsule depolymerases in a multihost Klebsiella bacteriophage and correlated the activities of the gene products to all hosts of this phage, providing an example of carriage of multiple depolymerases in a phage with a wide capsular type host spectrum. Moreover, we also established a recombineering system for modification of Klebsiella bacteriophage genomes and demonstrated the importance of capsule depolymerase for infecting specific hosts. Based on the powerful tool for modification of phage genome, further studies can be conducted to improve the understanding of mechanistic details of Klebsiella phage infection. Furthermore, the newly identified capsule depolymerases will be of great value for applications in capsular typing.

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