scholarly journals A Jacalin-like lectin-domain-containing protein of Sclerospora graminicola act as an apoplastic virulence effector in plant–oomycete interactions

2021 ◽  
Author(s):  
Michie Kobayashi ◽  
Hiroe Utsushi ◽  
Koki Fujisaki ◽  
Takumi Takeda ◽  
Tetsuro Yamashita ◽  
...  
Keyword(s):  
Plant Immunity ◽  
Foxtail Millet ◽  
Extracellular Fluid ◽  
Defense Responses ◽  
Mass Spectrometry Analysis ◽  
Phytophthora Palmivora ◽  
Sclerospora Graminicola ◽  
Lectin Domain ◽  
Spectrometry Analysis ◽  
Secretion Signal

SUMMARYThe plant extracellular space, including the apoplast and plasma membrane, is the initial site of plant– pathogen interactions. Pathogens deliver numerous secreted proteins, called effectors, into this region to suppress plant immunity and establish infection. Downy mildew caused by the oomycete pathogen Sclerospora graminicola (Sg) is an economically important disease of Poaceae crops including foxtail millet (Setaria italica). We previously reported the genome sequence of Sg and showed that the Jacalin-related lectin (JRL) gene family has significantly expanded in this lineage. However, the biological functions of JRL proteins remained unknown. Here, we show that JRL from S. graminicola (SgJRL) functions as an apoplastic virulence effector. We identified eight SgJRLs via protein mass spectrometry analysis of extracellular fluid from S. graminicola-inoculated foxtail millet leaves. SgJRLs consist of a Jacalin-like lectin domain and an N-terminal putative secretion signal, and SgJRL expression is induced by Sg infection. Heterologous expression of three SgJRLs with N-terminal secretion signal peptides in Nicotiana benthamiana enhanced the virulence of the pathogen Phytophthora palmivora inoculated onto the same leaves. Of the three SgJRLs, SG06536 fused with GFP localized to the apoplastic space in N. benthamiana leaves. INF1-mediated induction of defense-related genes was suppressed by co-expression of SG06536-GFP. These findings suggest that JRLs are novel apoplastic effectors that contribute to pathogenicity by suppressing plant defense responses.

scholarly journals Cryo-EM structure of coronavirus-HKU1 haemagglutinin esterase reveals architectural changes arising from prolonged circulation in humans

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel L. Hurdiss ◽  
Ieva Drulyte ◽  
Yifei Lang ◽  
Tatiana M. Shamorkina ◽  
Matti F. Pronker ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sialic Acid ◽  
Host Adaptation ◽  
Structure And Function ◽  
Mass Spectrometry Analysis ◽  
Lectin Domain ◽  
Spectrometry Analysis ◽  
Sialic Acid Binding ◽  
And Function ◽  
Insight Into

Abstract The human betacoronaviruses HKU1 and OC43 (subgenus Embecovirus) arose from separate zoonotic introductions, OC43 relatively recently and HKU1 apparently much longer ago. Embecovirus particles contain two surface projections called spike (S) and haemagglutinin-esterase (HE), with S mediating receptor binding and membrane fusion, and HE acting as a receptor-destroying enzyme. Together, they promote dynamic virion attachment to glycan-based receptors, specifically 9-O-acetylated sialic acid. Here we present the cryo-EM structure of the ~80 kDa, heavily glycosylated HKU1 HE at 3.4 Å resolution. Comparison with existing HE structures reveals a drastically truncated lectin domain, incompatible with sialic acid binding, but with the structure and function of the esterase domain left intact. Cryo-EM and mass spectrometry analysis reveals a putative glycan shield on the now redundant lectin domain. The findings further our insight into the evolution and host adaptation of human embecoviruses, and demonstrate the utility of cryo-EM for studying small, heavily glycosylated proteins.

scholarly journals Arabidopsis Lectin Receptor Kinases LecRK-IX.1 and LecRK-IX.2 Are Functional Analogs in Regulating Phytophthora Resistance and Plant Cell Death

2015 ◽  
Vol 28 (9) ◽  
pp. 1032-1048 ◽  
Author(s):  
Yan Wang ◽  
Jan H. G. Cordewener ◽  
Antoine H. P. America ◽  
Weixing Shan ◽  
Klaas Bouwmeester ◽  
...  
Keyword(s):  
Cell Death ◽  
Abc Transporter ◽  
Mitogen Activated Protein Kinase ◽  
Mass Spectrometry Analysis ◽  
In Planta ◽  
Lectin Domain ◽  
Spectrometry Analysis ◽  
Lectin Receptor ◽  
Receptor Kinases ◽  
Phytophthora Resistance

L-type lectin receptor kinases (LecRK) are potential immune receptors. Here, we characterized two closely-related Arabidopsis LecRK, LecRK-IX.1 and LecRK-IX.2, of which T-DNA insertion mutants showed compromised resistance to Phytophthora brassicae and Phytophthora capsici, with double mutants showing additive susceptibility. Overexpression of LecRK-IX.1 or LecRK-IX.2 in Arabidopsis and transient expression in Nicotiana benthamiana increased Phytophthora resistance but also induced cell death. Phytophthora resistance required both the lectin domain and kinase activity, but for cell death, the lectin domain was not needed. Silencing of the two closely related mitogen-activated protein kinase genes NbSIPK and NbNTF4 in N. benthamiana completely abolished LecRK-IX.1-induced cell death but not Phytophthora resistance. Liquid chromatography-mass spectrometry analysis of protein complexes coimmunoprecipitated in planta with LecRK-IX.1 or LecRK-IX.2 as bait, resulted in the identification of the N. benthamiana ABC transporter NbPDR1 as a potential interactor of both LecRK. The closest homolog of NbPDR1 in Arabidopsis is ABCG40, and coimmunoprecipitation experiments showed that ABCG40 associates with LecRK-IX.1 and LecRK-IX.2 in planta. Similar to the LecRK mutants, ABCG40 mutants showed compromised Phytophthora resistance. This study shows that LecRK-IX.1 and LecRK-IX.2 are Phytophthora resistance components that function independent of each other and independent of the cell-death phenotype. They both interact with the same ABC transporter, suggesting that they exploit similar signal transduction pathways.

scholarly journals Upregulation of Jasmonate-Inducible Defense Proteins and Differential Colonization of Roots of Oryza sativa Cultivars with the Endophyte Azoarcus sp.

2006 ◽  
Vol 19 (5) ◽  
pp. 502-511 ◽  
Author(s):  
Lucie Miché ◽  
Federico Battistoni ◽  
Sabrina Gemmer ◽  
Maya Belghazi ◽  
Barbara Reinhold-Hurek
Keyword(s):  
Oryza Sativa ◽  
Bacterial Colonization ◽  
Defense Responses ◽  
Mass Spectrometry Analysis ◽  
Compatible Interaction ◽  
Defense Proteins ◽  
Spectrometry Analysis ◽  
Rice Roots ◽  
Proteomic Approach ◽  
Pathogenesis Related

The endophyte Azoarcus sp. strain BH72 expresses nitrogenase (nif) genes inside rice roots. We applied a proteomic approach to dissect responses of rice roots toward bacterial colonization and jasmonic acid (JA) treatment. Two sister lineages of Oryza sativa were analyzed with cv. IR42 showing a less compatible interaction with the Azoarcus sp. resulting in slight root browning whereas cv. IR36 was successfully colonized as determined by nifH::gusA activity. External addition of JA inhibited colonization of roots and caused browning in contrast to the addition of ethylene, applied as ethephon (up to 5 mM). Only two of the proteins induced in cv. IR36 by JA were also induced by the endophyte (SalT, two isoforms). In contrast, seven JA-induced proteins were also induced by bacteria in cv. IR42, indicating that IR42 showed a stronger defense response. Mass spectrometry analysis identified these proteins as pathogenesis-related (PR) proteins (Prb1, RSOsPR10) or proteins sharing domains with receptorlike kinases induced by pathogens. Proteins strongly induced in roots in both varieties by JA were identified as Bowman-Birk trypsin inhibittors, germinlike protein, putative endo-1,3-beta-D-glucosidase, glutathion-S-transferase, and 1-propane-1-carboxylate oxidase synthase, peroxidase precursor, PR10-a, and a RAN protein previously not found to be JA-induced. Data suggest that plant defense responses involving JA may contribute to restricting endophytic colonization in grasses. Remarkably, in a compatible interaction with endophytes, JA-inducible stress or defense responses are apparently not important.

scholarly journals Cryo-EM structure of coronavirus-HKU1 haemagglutinin esterase reveals architectural changes arising from prolonged circulation in humans

2020 ◽  
Author(s):  
Daniel L. Hurdiss ◽  
Ieva Drulyte ◽  
Yifei Lang ◽  
Tatiana M. Shamorkina ◽  
Matti F. Pronker ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Mass Spectrometry Analysis ◽  
Loss Of Function ◽  
Human Respiratory Tract ◽  
Lectin Domain ◽  
Spectrometry Analysis ◽  
X Ray Crystallography ◽  
Sialic Acid Binding ◽  
And Function ◽  
Insight Into

AbstractThe human betacoronaviruses HKU1 and OC43 (subgenus Embecovirus) arose from separate zoonotic introductions, OC43 relatively recently and HKU1 apparently much longer ago. Embecovirus particles are studded with two types of surface projections called S (for spike) and HE (for haemagglutinin-esterase), with S mediating receptor-binding and membrane fusion and HE acting as a receptor-destroying enzyme. Together, they promote dynamic virion attachment to glycan-based receptors with 9-O-acetylated sialic acid as main constituent. We recently showed that adaptation of HKU1 and OC43 to replication in the human respiratory tract involved loss-of-function mutations in the lectin domain of HE. Here we present the cryo-EM structure of the ∼80 kDa, heavily glycosylated HKU1 HE at a global resolution of 3.4 Å. Comparison to existing HE structures reveals a drastically truncated lectin domain, incompatible with sialic acid binding, but with the structure and function of the HE esterase domain left intact. Our cryo-EM structure, in combination with mass spectrometry analysis, also describes the extent of glycosylation on the now redundant lectin domain, which forms a putative glycan shield. The findings further our insight into the evolution and host adaptation of human embecoviruses and also demonstrate the utility of cryo-EM for studying small, heavily glycosylated proteins which are intractable to X-ray crystallography.

Spectrophotometry Measurement of Polynuclear Aromatic Hydrocarbons in Hamilton Harbour Sediments

1991 ◽  
Vol 26 (1) ◽  
pp. 1-16 ◽  
Author(s):  
T.P. Murphy ◽  
H. Brouwer ◽  
M.E. Fox ◽  
E. Nagy
Keyword(s):  
Aromatic Hydrocarbons ◽  
Total Concentration ◽  
Coal Tar ◽  
Sediment Cores ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Near Surface ◽  
Spectrometry Analysis ◽  
Hamilton Harbour

Abstract Eighty-one sediment cores were collected to determine the extent of coal tar contamination in a toxic area of Hamilton Harbour. Over 800 samples were analyzed by a UV spectrophotometric technique that was standardized with gas chromatography/mass spectrometry analysis. The coal tar distribution was variable. The highest concentrations were near the Stelco outfalls and the Hamilton-Wentworth combined sewer outfalls. The total concentration of the 16 polynuclear aromatic hydrocarbons (PAHs) in 48,300 m3 of near-surface sediments exceeded 200 µg/g.

scholarly journals Effect of Ocular Hypertension on D-β-Aspartic Acid-Containing Proteins in the Retinas of Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Kanamoto ◽  
Takashi Tachibana ◽  
Yasushi Kitaoka ◽  
Toshio Hisatomi ◽  
Yasuhiro Ikeda ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ocular Hypertension ◽  
Aspartic Acid ◽  
Atp Synthase ◽  
Wistar Rats ◽  
Protein Band ◽  
Mass Spectrometry Analysis ◽  
Liquid Chromatography Mass Spectrometry ◽  
Spectrometry Analysis ◽  
Sds Page

Purpose. To investigate the effect of ocular hypertension-induced isomerization of aspartic acid in retinal proteins. Methods. Adult Wistar rats with ocular hypertension were used as an experimental model. D-β-aspartic acid-containing proteins were isolated by SDS-PAGE and western blot with an anti-D-β-aspartic acid antibody and identified by liquid chromatography-mass spectrometry analysis. The concentration of ATP was measured by ELISA. Results. D-β-aspartic acid was expressed in a protein band at around 44.5 kDa at much higher quantities in the retinas of rats with ocular hypertension than in those of normotensive rats. The 44.5 kDa protein band was mainly composed of α-enolase, S-arrestin, and ATP synthase subunits α and β, in both the ocular hypertensive and normotensive retinas. Moreover, increasing intraocular pressure was correlated with increasing ATP concentrations in the retinas of rats. Conclusion. Ocular hypertension affected the expression of proteins containing D-β-aspartic acid, including ATP synthase subunits, and up-regulation of ATP in the retinas of rats.

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