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Yu Jiao, Yinghao Chen, Chaofeng Ma, Jingjing Qin, Thi Hong Nhung Nguyen, Di Liu, Honghao Gan, Shen Ding, Zhi-Bin Luo
To investigate the physiological responses of poplars to amino acids as sole nitrogen (N) sources, Populus × canescens (Ait.) Smith plants were supplied with one of three nitrogen fertilizers (NH4NO3, phenylalanine (Phe) or the mixture of NH4NO3 and Phe) in sand culture. A larger root system, and decreased leaf size and CO2 assimilation rate was observed in Phe- versus NH4NO3-treated poplars. Consistently, a greater root biomass and a decreased shoot growth were detected in Phe-supplied poplars. Decreased enzymatic activities of nitrate reductase (NR), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) and elevated activities of nitrite reductase (NiR), phenylalanine ammonia lyase (PAL), glutamine synthetase (GS) and asparagine synthase (AS) were found in Phe-treated roots...
January 1, 2018: Tree Physiology
Xinghai Yang, Xiuzhong Xia, Zongqiong Zhang, Baoxuan Nong, Yu Zeng, Faqian Xiong, Yanyan Wu, Ju Gao, Guofu Deng, Danting Li
Nitrogen is a major nutritional element in rice production. However, excessive application of nitrogen fertilizer has caused severe environmental pollution. Therefore, development of rice varieties with improved nitrogen use efficiency (NUE) is urgent for sustainable agriculture. In this study, bulked segregant analysis (BSA) combined with whole genome re-sequencing (WGS) technology was applied to finely map quantitative trait loci (QTL) for NUE. A key QTL, designated as qNUE6 was identified on chromosome 6 and further validated by Insertion/Deletion (InDel) marker-based substitutional mapping in recombinants from F2 population (NIL-13B4 × GH998)...
2017: Frontiers in Plant Science
Jienan Han, Lifeng Wang, Hongyan Zheng, Xiaoying Pan, Huiyong Li, Fanjun Chen, Xuexian Li
ZD958 was the most low-N-efficient line among five maize and two teosinte lines. Zea parviglumis and Zea diploperennis were insensitive to N limitation. Maize and teosinte genetically and evolutionarily diverged in gene regulation. GDH2, ASN2, and T4 were consistently down-regulated across seven lines. Maternal asymmetric inheritance and heterosis vigor made ZD958 low-N-efficient. Nitrogen (N) deficiency remains a serious limiting factor for maize production in many developing countries. It is particularly important to better understand how hybrid maize responds to N limitation...
October 2015: Planta
Wissam Mansour, Hagit Hauschner, Uri Seligsohn, Nurit Rosenberg, Yulia Einav
The platelet integrin αIIbβ3 is widely accepted as a structural and a functional model of the broad integrin protein family. The four calcium-binding sites in the αIIb subunit contribute to biogenesis and stability of the protein. Mansour et al. (J Thromb Haemost 9:192-200, 2011) showed that the natural Asn2Asp mutation causing Glanzmann thrombasthenia, prevented surface expression of αIIbβ3, whereas the artificial Asn2Gln mutation only decreased its level. Molecular dynamics simulations and EDTA chelation assay were used here to explore the mechanism of these structural deformations...
October 2014: Protein Journal
Laure Gaufichon, Céline Masclaux-Daubresse, Guillaume Tcherkez, Michèle Reisdorf-Cren, Yukiko Sakakibara, Toshiharu Hase, Gilles Clément, Jean-Christophe Avice, Olivier Grandjean, Anne Marmagne, Stéphanie Boutet-Mercey, Marianne Azzopardi, Fabienne Soulay, Akira Suzuki
We investigated the function of ASN2, one of the three genes encoding asparagine synthetase (EC, which is the most highly expressed in vegetative leaves of Arabidopsis thaliana. Expression of ASN2 and parallel higher asparagine content in darkness suggest that leaf metabolism involves ASN2 for asparagine synthesis. In asn2-1 knockout and asn2-2 knockdown lines, ASN2 disruption caused a defective growth phenotype and ammonium accumulation. The asn2 mutant leaves displayed a depleted asparagine and an accumulation of alanine, GABA, pyruvate and fumarate, indicating an alanine formation from pyruvate through the GABA shunt to consume excess ammonium in the absence of asparagine synthesis...
February 2013: Plant, Cell & Environment
Mila Brum Ortigoza, Oliver Dibben, Jad Maamary, Luis Martinez-Gil, Victor H Leyva-Grado, Pablo Abreu, Juan Ayllon, Peter Palese, Megan L Shaw
Influenza viruses continue to pose a major public health threat worldwide and options for antiviral therapy are limited by the emergence of drug-resistant virus strains. The antiviral cytokine, interferon (IFN) is an essential mediator of the innate immune response and influenza viruses, like many viruses, have evolved strategies to evade this response, resulting in increased replication and enhanced pathogenicity. A cell-based assay that monitors IFN production was developed and applied in a high-throughput compound screen to identify molecules that restore the IFN response to influenza virus infected cells...
2012: PLoS Pathogens
Rashad Kebeish, Markus Niessen, Mehtap Oksaksin, Christian Blume, Christoph Peterhaensel
The effect of constitutive and dark-induced expression of Solanum tuberosum phosphoenolpyruvate carboxylase (PEPC) on the opening state of stomata and photosynthetic performance in Arabidopsis thaliana plants was studied. Transcript accumulation analyses of the A. thaliana dark-induced (Din10 and Din6) and the Pisum sativum asparagine synthetase 2 promoters (Asn2) in transiently transformed tobacco leaves showed that Din10 promoter induced more DsRed accumulation in the dark compared to the other din genes...
February 2012: Biotechnology and Bioengineering
Maike M Vetter, Hans-M Zenn, Eva Méndez, Heidrun van den Boom, Friedrich W Herberg, Bjørn S Skålhegg
BACKGROUND: The two variants of the α-form of the catalytic (C) subunit of protein kinase A (PKA), designated Cα1 and Cα2, are encoded by the PRKACA gene. Whereas Cα1 is ubiquitous, Cα2 expression is restricted to the sperm cell. Cα1 and Cα2 are encoded with different N-terminal domains. In Cα1 but not Cα2 the N-terminal end introduces three sites for posttranslational modifications which include myristylation at Gly1, Asp-specific deamidation at Asn2 and autophosphorylation at Ser10...
2011: BMC Biochemistry
Houda Maaroufi-Dguimi, Mohamed Debouba, Laure Gaufichon, Gilles Clément, Houda Gouia, Afef Hajjaji, Akira Suzuki
Salt tolerance of Arabidopsis knockout mutant with T-DNA insertion in ASN2 gene encoding asparagine synthetase (AS, EC (asn2-1) was investigated. Wild-type Arabidopsis Col0 and asn2-1 mutant were grown for one month by hydroponic culture and subjected to 100 mM NaCl stress for a short time from 6 to 24 h. The salt treatment decreased chlorophyll and soluble protein contents, and increased ammonium level in the asn2-1 leaves. The salinity induced ASN1 mRNA level in the wild-type and asn2-1 leaves. By contrast, the salt treatment inhibited the transcript and protein levels of chloroplastic glutamine synthetase 2 (GS2, EC 6...
June 2011: Plant Physiology and Biochemistry: PPB
W Mansour, Y Einav, H Hauschner, A Koren, U Seligsohn, N Rosenberg
BACKGROUND: Studies of Glanzmann thrombasthenia (GT)-causing mutations has generated invaluable information on the formation and function of integrin αIIbβ(3). OBJECTIVE: To characterize the mutation in four siblings of an Israeli Arab family affected by GT, and to analyze the relationships between the mutant protein structure and its function using artificial mutations. METHODS AND RESULTS: Sequencing disclosed a new A97G transversion in the αIIb gene predicting Asn2Asp substitution at blade 1 of the β-propeller...
January 2011: Journal of Thrombosis and Haemostasis: JTH
Roger J S Preston, Colin Morse, Sherina L Murden, Sara Kate Brady, James S O'Donnell, Andrew D Mumford
We report a kindred with heritable protein C (PC) deficiency in which two siblings with severe thrombosis showed a composite type I and IIb PC deficiency phenotype, identified using commercial PC assays (proband: PC antigen 42 u/dl, amidolytic activity 40 u/dl, anticoagulant activity 9 u/dl). The independent PROC nucleotide variations c.669C>A (predictive of Ser181Arg) and c.131C>T (predictive of Asn2Ile) segregated with the type I and type IIb PC deficiency phenotypes respectively, but co-segregated in the siblings with severe thrombosis...
March 2009: British Journal of Haematology
Esmeralda Parra-Peralbo, Manuel Pineda, Miguel Aguilar
A gene encoding a putative asparagine synthetase (AS; EC has been isolated from common bean (Phaseolus vulgaris). A 2.4 kb cDNA clone of this gene (PVAS3) encodes a protein of 570 amino acids with a predicted molecular mass of 64,678 Da, an isoelectric point of 6.45, and a net charge of -5.9 at pH 7.0. The PVAS3 protein sequence conserves all the amino acid residues that are essential for glutamine-dependent AS, and PVAS3 complemented an E. coli asparagine auxotroph, that demonstrates that it encodes a glutamine-dependent AS...
November 2009: Molecular Biology Reports
Shenggen Yao, Min-Min Zhang, Doju Yoshikami, Layla Azam, Baldomero M Olivera, Grzegorz Bulaj, Raymond S Norton
mu-SIIIA, a novel mu-conotoxin from Conus striatus, appeared to be a selective blocker of tetrodotoxin-resistant sodium channels in frog preparations. It also exhibited potent analgesic activity in mice, although its selectivity profile against mammalian sodium channels remains unknown. We have determined the structure of mu-SIIIA in aqueous solution and characterized its backbone dynamics by NMR and its functional properties electrophysiologically. Consistent with the absence of hydroxyprolines, mu-SIIIA adopts a single conformation with all peptide bonds in the trans conformation...
October 14, 2008: Biochemistry
Satoshi Watanabe, Masahito Tada, Tomoyasu Aizawa, Masanobu Yoshida, Tadamasa Sugaya, Makoto Taguchi, Takahide Kouno, Takashi Nakamura, Mineyuki Mizuguchi, Makoto Demura, Yoichi Hayakawa, Keiichi Kawano
GBP, a small insect cytokine isolated from lepidopterans, has a variety of functions. We constructed a series of mutants focusing on the unstructured N-terminal residues of GBP by acetylation, deletion, and elongation in order to investigate the interaction between GBP and its receptor in plasmatocytes. The 1H NMR spectra showed no significant changes in the tertiary structures of these peptides, which indicated that all the mutants maintained their core beta-sheet structures. The deletion and acetylated mutants, 2-25GBP, Ac2-25GBP, and AcGBP, lost their activity...
2006: Protein and Peptide Letters
Sipho Mamputha, Zhi-Liang Lu, Roger W Roeske, Robert P Millar, Arieh A Katz, Colleen A Flanagan
GnRH I regulates reproduction. A second form, designated GnRH II, selectively binds type II GnRH receptors. Amino acids of the type I GnRH receptor required for binding of GnRH I (Asp2.61(98), Asn2.65(102), and Lys3.32(121)) are conserved in the type II GnRH receptor, but their roles in receptor function are unknown. We have delineated their functions using mutagenesis, signaling and binding assays, immunoblotting, and computational modeling. Mutating Asp2.61(97) to Glu or Ala, Asn2.65(101) to Ala, or Lys3...
January 2007: Molecular Endocrinology
Yasuto Todokoro, Ikuko Yumen, Kei Fukushima, Shin-Won Kang, Jang-Su Park, Toshiyuki Kohno, Kaori Wakamatsu, Hideo Akutsu, Toshimichi Fujiwara
The structure of mastoparan-X (MP-X), a G-protein activating peptide from wasp venom, in the state tightly bound to anionic phospholipid bilayers was determined by solid-state NMR spectroscopy. Carbon-13 and nitrogen-15 NMR signals of uniformly labeled MP-X were completely assigned by multidimensional intraresidue C-C, N-CalphaCbeta, and N-Calpha-C', and interresidue Calpha-CalphaCbeta, N-CalphaCbeta, and N-C'-Calpha correlation experiments. The backbone torsion angles were predicted from the chemical shifts of 13C', 13Calpha, 13Cbeta, and 15N signals with the aid of protein NMR database programs...
August 15, 2006: Biophysical Journal
Arin Ghasparian, Kerstin Moehle, Anthony Linden, John A Robinson
A crystal structure is reported of the peptide Ac-Ala-Asn-Pro-Asn-Ala-NH2, representing the immunodominant region of the major surface protein on the malaria parasite; the NPNA motif adopts a type-I beta-turn, which is stabilized by hydrogen bonding between the CO of Asn2 and the NH of Ala5 as well as between the O(delta) of Asn2 and the NH of Asn4.
January 14, 2006: Chemical Communications: Chem Comm
Todd E Gillis, Bo Liang, Franca Chung, Glen F Tibbits
The Ca2+ sensitivity of force generation in trout cardiac myocytes is significantly greater than that from mammalian hearts. One mechanism that we have suggested to be responsible, at least in part, for this high Ca2+ sensitivity is the isoform of cardiac troponin C (cTnC) found in trout hearts (ScTnC), which has greater than twice the Ca2+ affinity of mammalian cTnC (McTnC). Here, through a series of mutations, the residues in ScTnC responsible for its high Ca2+ affinity have been identified as being Asn2, Ile28, Gln29, and Asp30...
June 16, 2005: Physiological Genomics
Hon-Kit Wong, Hiu-Ki Chan, Gloria M Coruzzi, Hon-Ming Lam
In Arabidopsis, asparagine (Asn) synthetase is encoded by a small gene family (ASN1, ASN2, and ASN3). It has been shown that ASN1 and ASN2 exhibit reciprocal gene expression patterns toward light and metabolites. Moreover, changes in total free Asn levels parallel the expression of ASN1, but not ASN2. In this study, we show that ASN2 expression correlates with ammonium metabolism. We demonstrate that the light induction of ASN2 is ammonium dependent. The addition and removal of ammonium exerted fast and reciprocal effects on the levels of ASN2 mRNA, specifically under light-grown conditions...
January 2004: Plant Physiology
Seetharama D S Jois, Ambikaipakan Balasubramaniam
Two NPY analogue peptides, BVD10 (Ile-Asn-Pro-Ile-Tyr-Arg-Leu-Arg-Tyr-OMe) and BVD15 (Ile-Asn-Pro-Ile-Tyr-Arg-Leu-Arg-Tyr-NH(2)) were characterized conformationally by NMR, CD and molecular dynamics simulations. The two peptides exhibit different secondary structure characteristics in trifluoroethanol. BVD10 exhibits a structure with two consecutive beta-turns at Asn2-Pro3-Ile4-Tyr5 and Ile4-Tyr5-Arg6-Leu7. BVD15 exhibits a helical type of structure along with a beta-turn at Asn2-Pro3-Ile4-Tyr5. Molecular modeling studies suggested that the C-terminus Tyr9 is oriented in different directions in the two peptides...
July 2003: Peptides
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