scholarly journals Identification of sulfenylated cysteines in Arabidopsis thaliana proteins using a disulfide-linked peptide reporter

2020 ◽  
Author(s):  
Bo Wei ◽  
Patrick Willems ◽  
Jingjing Huang ◽  
Caiping Tian ◽  
Jing Yang ◽  
...  

ABSTRACTIn proteins, hydrogen peroxide (H2O2) reacts with redox-sensitive cysteines to form cysteine sulfenic acid, also known as S-sulfenylation. These cysteine oxidation events can steer diverse cellular processes by altering protein interactions, trafficking, conformation, and function. Previously, we had identified S-sulfenylated proteins by using a tagged proteinaceous probe based on the yeast AP-1–like (Yap1) transcription factor that specifically reacts with sulfenic acids and traps them through a mixed disulfide bond. However, the identity of the S-sulfenylated amino acid residues remained enigmatic. Here, we present a technological advancement to identify in situ sulfenylated cysteines directly by means of the transgenic Yap1 probe. In Arabidopsis thaliana cells, after an initial affinity purification and a tryptic digestion, we further enriched the mixed disulfide-linked peptides with an antibody targeting the YAP1C-derived peptide (C598SEIWDR) that entails the redox-active cysteine. Subsequent mass spectrometry analysis with pLink 2 identified 1,745 YAP1C cross-linked peptides, indicating sulfenylated cysteines in over 1,000 proteins. Approximately 55% of these YAP1C-linked cysteines had previously been reported as redox-sensitive cysteines (S-sulfenylation, S-nitrosylation, and reversibly oxidized cysteines). The presented methodology provides a noninvasive approach to identify sulfenylated cysteines in any species that can be genetically modified.

2014 ◽  
Vol 306 (9) ◽  
pp. C805-C818 ◽  
Author(s):  
Priyanka Kohli ◽  
Malte P. Bartram ◽  
Sandra Habbig ◽  
Caroline Pahmeyer ◽  
Tobias Lamkemeyer ◽  
...  

The function of an individual protein is typically defined by protein-protein interactions orchestrating the formation of large complexes critical for a wide variety of biological processes. Over the last decade the analysis of purified protein complexes by mass spectrometry became a key technique to identify protein-protein interactions. We present a fast and straightforward approach for analyses of interacting proteins combining a Flp-in single-copy cellular integration system and single-step affinity purification with single-shot mass spectrometry analysis. We applied this protocol to the analysis of the YAP and TAZ interactome. YAP and TAZ are the downstream effectors of the mammalian Hippo tumor suppressor pathway. Our study provides comprehensive interactomes for both YAP and TAZ and does not only confirm the majority of previously described interactors but, strikingly, revealed uncharacterized interaction partners that affect YAP/TAZ TEAD-dependent transcription. Among these newly identified candidates are Rassf8, thymopoetin, and the transcription factors CCAAT/enhancer-binding protein (C/EBP)β/δ and core-binding factor subunit β (Cbfb). In addition, our data allowed insights into complex stoichiometry and uncovered discrepancies between the YAP and TAZ interactomes. Taken together, the stringent approach presented here could help to significantly sharpen the understanding of protein-protein networks.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1804
Author(s):  
Izabela Perkowska ◽  
Joanna Siwinska ◽  
Alexandre Olry ◽  
Jérémy Grosjean ◽  
Alain Hehn ◽  
...  

Coumarins are phytochemicals occurring in the plant kingdom, which biosynthesis is induced under various stress factors. They belong to the wide class of specialized metabolites well known for their beneficial properties. Due to their high and wide biological activities, coumarins are important not only for the survival of plants in changing environmental conditions, but are of great importance in the pharmaceutical industry and are an active source for drug development. The identification of coumarins from natural sources has been reported for different plant species including a model plant Arabidopsis thaliana. In our previous work, we demonstrated a presence of naturally occurring intraspecies variation in the concentrations of scopoletin and its glycoside, scopolin, the major coumarins accumulating in Arabidopsis roots. Here, we expanded this work by examining a larger group of 28 Arabidopsis natural populations (called accessions) and by extracting and analysing coumarins from two different types of tissues–roots and leaves. In the current work, by quantifying the coumarin content in plant extracts with ultra-high-performance liquid chromatography coupled with a mass spectrometry analysis (UHPLC-MS), we detected a significant natural variation in the content of simple coumarins like scopoletin, umbelliferone and esculetin together with their glycosides: scopolin, skimmin and esculin, respectively. Increasing our knowledge of coumarin accumulation in Arabidopsis natural populations, might be beneficial for the future discovery of physiological mechanisms of action of various alleles involved in their biosynthesis. A better understanding of biosynthetic pathways of biologically active compounds is the prerequisite step in undertaking a metabolic engineering research.


2021 ◽  
Vol 14 (680) ◽  
pp. eaaw4673
Author(s):  
Natalia Zamorano Cuervo ◽  
Audray Fortin ◽  
Elise Caron ◽  
Stéfany Chartier ◽  
Nathalie Grandvaux

Protein function is regulated by posttranslational modifications (PTMs), among which reversible oxidation of cysteine residues has emerged as a key regulatory mechanism of cellular responses. Given the redox regulation of virus-host interactions, the identification of oxidized cysteine sites in cells is essential to understand the underlying mechanisms involved. Here, we present a proteome-wide identification of reversibly oxidized cysteine sites in oxidant-treated cells using a maleimide-based bioswitch method coupled to mass spectrometry analysis. We identified 2720 unique oxidized cysteine sites within 1473 proteins with distinct abundances, locations, and functions. Oxidized cysteine sites were found in numerous signaling pathways, many relevant to virus-host interactions. We focused on the oxidation of STING, the central adaptor of the innate immune type I interferon pathway, which is stimulated in response to the detection of cytosolic DNA by cGAS. We demonstrated the reversible oxidation of Cys148 and Cys206 of STING in cells. Molecular analyses led us to establish a model in which Cys148 oxidation is constitutive, whereas Cys206 oxidation is inducible by oxidative stress or by the natural ligand of STING, 2′3′-cGAMP. Our data suggest that the oxidation of Cys206 prevented hyperactivation of STING by causing a conformational change associated with the formation of inactive polymers containing intermolecular disulfide bonds. This finding should aid the design of therapies targeting STING that are relevant to autoinflammatory disorders, immunotherapies, and vaccines.


2019 ◽  
Vol 116 (38) ◽  
pp. 19136-19144 ◽  
Author(s):  
Giel P. Göertz ◽  
Joyce W. M. van Bree ◽  
Anwar Hiralal ◽  
Bas M. Fernhout ◽  
Carmen Steffens ◽  
...  

Zika virus (ZIKV) is an arthropod-borne flavivirus predominantly transmitted by Aedes aegypti mosquitoes and poses a global human health threat. All flaviviruses, including those that exclusively replicate in mosquitoes, produce a highly abundant, noncoding subgenomic flavivirus RNA (sfRNA) in infected cells, which implies an important function of sfRNA during mosquito infection. Currently, the role of sfRNA in flavivirus transmission by mosquitoes is not well understood. Here, we demonstrate that an sfRNA-deficient ZIKV (ZIKVΔSF1) replicates similar to wild-type ZIKV in mosquito cell culture but is severely attenuated in transmission by Ae. aegypti after an infectious blood meal, with 5% saliva-positive mosquitoes for ZIKVΔSF1 vs. 31% for ZIKV. Furthermore, viral titers in the mosquito saliva were lower for ZIKVΔSF1 as compared to ZIKV. Comparison of mosquito infection via infectious blood meals and intrathoracic injections showed that sfRNA is important for ZIKV to overcome the mosquito midgut barrier and to promote virus accumulation in the saliva. Next-generation sequencing of infected mosquitoes showed that viral small-interfering RNAs were elevated upon ZIKVΔSF1 as compared to ZIKV infection. RNA-affinity purification followed by mass spectrometry analysis uncovered that sfRNA specifically interacts with a specific set of Ae. aegypti proteins that are normally associated with RNA turnover and protein translation. The DEAD/H-box helicase ME31B showed the highest affinity for sfRNA and displayed antiviral activity against ZIKV in Ae. aegypti cells. Based on these results, we present a mechanistic model in which sfRNA sequesters ME31B to promote flavivirus replication and virion production to facilitate transmission by mosquitoes.


2019 ◽  
Vol 10 (19) ◽  
pp. 5146-5155 ◽  
Author(s):  
Di Wu ◽  
Jingwen Li ◽  
Weston B. Struwe ◽  
Carol V. Robinson

A lectin affinity purification-mass spectrometry approach to characterize lectin-reactive glycoproteoforms and elucidate lectin specificities at the intact protein level.


2007 ◽  
Vol 189 (21) ◽  
pp. 7819-7828 ◽  
Author(s):  
Yan Ge ◽  
Yasuko Rikihisa

ABSTRACT Anaplasma phagocytophilum is the etiologic agent of human granulocytic anaplasmosis (HGA), one of the major tick-borne zoonoses in the United States. The surface of A. phagocytophilum plays a crucial role in subverting the hostile host cell environment. However, except for the P44/Msp2 outer membrane protein family, the surface components of A. phagocytophilum are largely unknown. To identify the major surface proteins of A. phagocytophilum, a membrane-impermeable, cleavable biotin reagent, sulfosuccinimidyl-2-[biotinamido]ethyl-1,3-dithiopropionate (Sulfo-NHS-SS-Biotin), was used to label intact bacteria. The biotinylated bacterial surface proteins were isolated by streptavidin agarose affinity purification and then separated by electrophoresis, followed by capillary liquid chromatography-nanospray tandem mass spectrometry analysis. Among the major proteins captured by affinity purification were five A. phagocytophilum proteins, Omp85, hypothetical proteins APH_0404 (designated Asp62) and APH_0405 (designated Asp55), P44 family proteins, and Omp-1A. The surface exposure of Asp62 and Asp55 was verified by immunofluorescence microscopy. Recombinant Asp62 and Asp55 proteins were recognized by an HGA patient serum. Anti-Asp62 and anti-Asp55 peptide sera partially neutralized A. phagocytophilum infection of HL-60 cells in vitro. We found that the Asp62 and Asp55 genes were cotranscribed and conserved among members of the family Anaplasmataceae. With the exception of P44-18, all of the proteins were newly revealed major surface-exposed proteins whose study should facilitate understanding the interaction between A. phagocytophilum and the host. These proteins may serve as targets for development of chemotherapy, diagnostics, and vaccines.


2001 ◽  
Vol 12 (11) ◽  
pp. 3340-3352 ◽  
Author(s):  
Steven M. Murphy ◽  
Andrea M. Preble ◽  
Urvashi K. Patel ◽  
Kathy L. O'Connell ◽  
D. Prabha Dias ◽  
...  

The γ-tubulin complex is a large multiprotein complex that is required for microtubule nucleation at the centrosome. Here we report the purification and characterization of the human γ-tubulin complex and the identification of its subunits. The human γ-tubulin complex is a ring of ∼25 nm, has a subunit structure similar to that reported for γ-tubulin complexes from other species, and is able to nucleate microtubule polymerization in vitro. Mass spectrometry analysis of the human γ-tubulin complex components confirmed the presence of four previously identified components (γ-tubulin and γ-tubulin complex proteins [GCPs] 2, 3, and 4) and led to the identification of two new components, GCP5 and GCP6. Sequence analysis revealed that the GCPs share five regions of sequence similarity and define a novel protein superfamily that is conserved in metazoans. GCP5 and GCP6, like other components of the γ-tubulin complex, localize to the centrosome and associate with microtubules, suggesting that the entire γ-tubulin complex takes part in both of these interactions. Stoichiometry experiments revealed that there is a single copy of GCP5 and multiple copies of γ-tubulin, GCP2, GCP3, and GCP4 within the γ-tubulin complex. Thus, the γ-tubulin complex is conserved in structure and function, suggesting that the mechanism of microtubule nucleation is conserved.


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