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51.
Jinping Wei Xiaodong Wang Zeyu Hu Xiaojie Wang Jialiu Wang Jianfeng Wang Xueling Huang Zhensheng Kang Chunlei Tang 《植物学报(英文版)》2023,65(1):249-264
The obligate biotrophic fungus Puccinia striiformis f. sp. tritici (Pst) employs virulence effectors to disturb host immunity and causes devastating stripe rust disease. However, our understanding of how Pst effectors regulate host defense responses remains limited. In this study, we determined that the Pst effector Hasp98, which is highly expressed in Pst haustoria, inhibits plant immune responses triggered by flg22 or nonpathogenic bacteria. Overexpression of Hasp98 in wheat (Triticum aestivum) suppressed avirulent Pst-triggered immunity, leading to decreased H2O2 accumulation and promoting P. striiformis infection, whereas stable silencing of Hasp98 impaired P. striiformis pathogenicity. Hasp98 interacts with the wheat mitogen-activated protein kinase TaMAPK4, a positive regulator of plant resistance to stripe rust. The conserved TEY motif of TaMAPK4 is important for its kinase activity, which is required for the resistance function. We demonstrate that Hasp98 inhibits the kinase activity of TaMAPK4 and that the stable silencing of TaMAPK4 compromises wheat resistance against P. striiformis. These results suggest that Hasp98 acts as a virulence effector to interfere with the MAPK signaling pathway in wheat, thereby promoting P. striiformis infection. 相似文献
52.
Microtubule dynamics and organization are important for plant cell morphogenesis and development. The microtubule-based motor protein kinesins are mainly responsible for the transport of some organelles and vesicles, although several have also been shown to regulate microtubule organization. The ARMADILLO REPEAT KINESIN (ARK) family is a plant-specific motor protein subfamily that consists of three members (ARK1, ARK2, and ARK3) in Arabidopsis thaliana. ARK2 has been shown to participate in root epidermal cell morphogenesis. However, whether and how ARK2 associates with microtubules needs further elucidation. Here, we demonstrated that ARK2 co-localizes with microtubules and facilitates microtubule bundling in vitro and in vivo. Pharmacological assays and microtubule dynamics analyses indicated that ARK2 stabilizes cortical microtubules. Live-cell imaging revealed that ARK2 moves along cortical microtubules in a processive mode and localizes both at the plus-end and the sidewall of microtubules. ARK2 therefore tracks and stabilizes the growing plus-ends of microtubules, which facilitates the formation of parallel microtubule bundles. 相似文献
53.
James Kang William Low Thomas Norberg Jill Meisenhelder Karin Hansson Johan Stenflo Guo-Ping Zhou Julita Imperial Baldomero M Olivera Alan C Rigby A Grey Craig 《European journal of biochemistry》2004,271(23-24):4939-4949
The 13-amino acid glycopeptide tx5a (Gla-Cys-Cys-Gla-Asp-Gly-Trp*-Cys-Cys-Thr*-Ala-Ala-Hyp-OH, where Trp* = 6-bromotryptophan and Thr* = Gal-GalNAc-threonine), isolated from Conus textile, causes hyperactivity and spasticity when injected intracerebral ventricularly into mice. It contains nine post-translationally modified residues: four cysteine residues, two gamma-carboxyglutamic acid residues, and one residue each of 6-bromotryptophan, 4-trans-hydroxyproline and glycosylated threonine. The chemical nature of each of these has been determined with the exception of the glycan linkage pattern on threonine and the stereochemistry of the 6-bromotryptophan residue. Previous investigations have demonstrated that tx5a contains a disaccharide composed of N-acetylgalactosamine (GalNAc) and galactose (Gal), but the interresidue linkage was not characterized. We hypothesized that tx5a contained the T-antigen, beta-D-Gal-(1-->3)-alpha-D-GalNAc, one of the most common O-linked glycan structures, identified previously in another Conus glycopeptide, contalukin-G. We therefore utilized the peracetylated form of this glycan attached to Fmoc-threonine in an attempted synthesis. While the result-ing synthetic peptide (Gla-Cys-Cys-Gla-Asp-Gly-Trp*-Cys-Cys-Thr*-Ala-Ala-Hyp-OH, where Trp* =6-bromotryptophan and Thr* = beta-D-Gal-(1-->3)-alpha-D-GalNAc-threonine) and the native peptide had almost identical mass spectra, a comparison of their RP-HPLC chromatograms suggested that the two forms were not identical. Two-dimensional 1H homonuclear and 13C-1H heteronuclear NMR spectroscopy of native tx5a isolated from Conus textile was then used to determine that the glycan present on tx5a indeed is not the aforementioned T-antigen, but rather alpha-D-Gal-(1-->3)-alpha-D-GalNAc. 相似文献
54.
SEO Dong-Hwan† Seock-Yeon HWANG† Jikhyon HAN Sang-Kyun KOH Iksoo KIM Kang Sun RYU Chi-Young YUN 《Entomological Research》2004,34(3):207-211
This study was performed to explore novel and valuable uses of insect resources, important subjects of the natural compound used in bio‐industries. The whole bodies of two crickets, Gryllus bimaculatus and Teleogryllus emma, selected from medicinal insect species, were carefully ground and treated with 80% EtOH. The insect extracts were solubilized and separated by hexane, butanol, and D.W according to their polarities. Three types of extracts, a D.W fraction (G1) and a boiling extract (G2) of an introduced cricket, G. bimaculatus, and a D.W fraction (T1) of a Korean local cricket, T. emma, were prepared to assay immune stimulating activity of cricket originated compounds. The all of three treated cricket extracts showed to increase IL‐4, IFN‐, and TNF‐α. Among those extract, extract G2, boiled extract from G. bimaculatus, was the best immune–enhancing fraction. The results of this study could be fundamental information for further works to use insects as natural resources having plenty of potentials and varieties. 相似文献
55.
两种药用黄芪比较生物学研究 总被引:10,自引:1,他引:9
通过栽培实验,本文对两种药用黄芪的个体发育节律,根,茎,叶,花及种子的生物学特性进行了较系统的比较研究,为确定蒙古黄芪(AstragalusmongholicusBunge)为独立的种,提供了更为全面的依据。 相似文献
56.
Li Ming Leong Paul M. Brickell 《The international journal of biochemistry & cell biology》1996,28(12):1293-1296
Bone morphogenetic protein-4 (BMP-4) is one of nine structurally related BMPs belonging to the transforming growth factor-β (TGF-β) superfamily of secreted proteins. Mature BMP-4 is a dimer that binds to a multimeric transmembrane receptor with serine/threonine kinase activity. Although discovered because it stimulates bone formation in adult mammals, BMP-4 has important roles as a signalling molecule in embryonic tissues, including the developing central and peripheral nervous system, musculature and skeleton. It participates in an ancient signalling pathway also found in insects and worms. Nevertheless, the main practical application of BMPs is for stimulating repair of bone, and their use in humans is currently being assessed. 相似文献
57.
猪精子中与卵透明带糖蛋白ZP3结合的蛋白质 总被引:3,自引:0,他引:3
依次经PSL-Sepharose亲和层析柱和纤维素CM-52离子交换层析柱,从猪精子的CHAPS抽提液分离得4个蛋白质组分。用固相透明带精蛋白结合试验(IZPGBA)检测;表明精子蛋白SP1和SP2具有结合透明带糖蛋白ZP3的活性,SP2并显示凝集血球的活性。精子蛋白SP1与卵预温育明显抑制精卵结合,抑制活性与加入的精子蛋白的浓度呈正相关。用生物素标记的ZP3和蛋白质印迹技术,证明SP1中的68kD精子蛋白与ZP3结合,提示68kD精子蛋白参与精卵结合。 相似文献
58.
应用二维电泳技术,分析了经水分胁迫(PEG)、盐分胁迫(NaCl)和热激(40℃)处理后林生山黧豆(LathyrussylvestrisL.)体内蛋白质多肽及其含量的变化。有些蛋白质经PEG、NaCl和热激处理后可以产生相同的变化。两种不同的胁迫因子对某些蛋白质的影响有一定的共同性。特定的胁迫条件可以造成特定的影响。不同胁迫因子对同一蛋白质多肽可以造成不同的影响。胁迫下蛋白质的变化可能与林生山黧豆抵抗和适应胁迫条件的能力以及体内非蛋白质氨基酸的代谢有关 相似文献
59.
Chang WC Shyu WJ Shi GY Lin MT Jen CJ Wing LY Tang MJ Wu HL 《Journal of biomedical science》1996,3(1):59-66
Treatment of cultured bovine carotid artery endothelial cells with 0.1 µM human plasmin has been reported to induce a receptor-mediated short burst of arachidonate release, which is a pertussis toxin-sensitive and extracellular calcium-dependent reaction. Plasmin-induced calcium influx in cells was significantly inhibited by pretreatment with pertussis toxin, indicating that the former was coupled with a pertussis toxin-sensitive guanosine 5-triphosphate (GTP)-binding protein. Plasmin significantly induced the formation of lysophosphatidylcholine but not lysophosphatidylethanolamine. A cellular phospholipase A2 with an arachidonyl specificity at the sn-2 position of phosphatidylcholine, which required submicromolar calcium, was identified as a cytosolic phospholipase A2 by immunoblot analysis. By a cell-free enzyme activity assay and immunoblot analysis, plasmin was found to induce a translocation of the cytosolic phospholipase A2 from the cytosol to the membrane. Taken together, the results suggest that plasmin bound to its putative receptor and activated a GTP-binding protein coupled to calcium influx channel, followed by translocation and activation of cytosolic phospholipase A2 in endothelial cells. 相似文献
60.
A procedure is described, based on a spline-function representation of ab initio peptide conformational geometry maps, that allows one to predict backbone bond distances and angles of proteins as functions of the peptide ?(N-Cα)/Ψ(Cα-C′) torsions with an accuracy comparable to that of high-resolution protein crystallography. For example, for the more than 40 residues of crambin, the rms deviation between predicted and crystallographic values of N-Cα-C′ is 1.9° for the 1.5 Å resolution structure and 1.9° for the 0.83 Å resolution structure, compared with angle variations of < 10°. Accurate information on protein backbone geometries is important for establishing dictionaries of flexible geometry functions for use in empirical peptide and protein modeling. © 1995 John Wiley & Sons, Inc. 相似文献