scholarly journals Insights Into the Polerovirus–Plant Interactome Revealed by Coimmunoprecipitation and Mass Spectrometry

2015 ◽  
Vol 28 (4) ◽  
pp. 467-481 ◽  
Author(s):  
Stacy L. DeBlasio ◽  
Richard Johnson ◽  
Jaclyn Mahoney ◽  
Alexander Karasev ◽  
Stewart M. Gray ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Carbon Fixation ◽  
Dynamic Range ◽  
High Resolution Mass Spectrometry ◽  
Protein Complexes ◽  
Interaction Network ◽  
Host Protein ◽  
Host Proteins ◽  
Leafroll Virus ◽  
Readthrough Protein

Identification of host proteins interacting with the aphidborne Potato leafroll virus (PLRV) from the genus Polerovirus, family Luteoviridae, is a critical step toward understanding how PLRV and related viruses infect plants. However, the tight spatial distribution of PLRV to phloem tissues poses challenges. A polyclonal antibody raised against purified PLRV virions was used to coimmunoprecipitate virus-host protein complexes from Nicotiana benthamiana tissue inoculated with an infectious PLRV cDNA clone using Agrobacterium tumefaciens. A. tumefaciens-mediated delivery of PLRV enabled infection and production of assembled, insect-transmissible virus in most leaf cells, overcoming the dynamic range constraint posed by a systemically infected host. Isolated protein complexes were characterized using high-resolution mass spectrometry and consisted of host proteins interacting directly or indirectly with virions, as well as the nonincorporated readthrough protein (RTP) and three phosphorylated positional isomers of the RTP. A bioinformatics analysis using ClueGO and STRING showed that plant proteins in the PLRV protein interaction network regulate key biochemical processes, including carbon fixation, amino acid biosynthesis, ion transport, protein folding, and trafficking.

scholarly journals Visualization of Host-Polerovirus Interaction Topologies Using Protein Interaction Reporter Technology

2015 ◽  
Vol 90 (4) ◽  
pp. 1973-1987 ◽  
Author(s):  
Stacy L. DeBlasio ◽  
Juan D. Chavez ◽  
Mariko M. Alexander ◽  
John Ramsey ◽  
Jimmy K. Eng ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Protein Interaction ◽  
Protein Interactions ◽  
Interaction Network ◽  
Host Protein ◽  
Host Proteins ◽  
Content Type ◽  
Host Pathogen ◽  
Pathogen Protein ◽  
Binding Interfaces

ABSTRACTDemonstrating direct interactions between host and virus proteins during infection is a major goal and challenge for the field of virology. Most protein interactions are not binary or easily amenable to structural determination. Using infectious preparations of a polerovirus (Potato leafroll virus[PLRV]) and protein interaction reporter (PIR), a revolutionary technology that couples a mass spectrometric-cleavable chemical cross-linker with high-resolution mass spectrometry, we provide the first report of a host-pathogen protein interaction network that includes data-derived, topological features for every cross-linked site that was identified. We show that PLRV virions have hot spots of protein interaction and multifunctional surface topologies, revealing how these plant viruses maximize their use of binding interfaces. Modeling data, guided by cross-linking constraints, suggest asymmetric packing of the major capsid protein in the virion, which supports previous epitope mapping studies. Protein interaction topologies are conserved with other species in theLuteoviridaeand with unrelated viruses in theHerpesviridaeandAdenoviridae. Functional analysis of three PLRV-interacting host proteinsin plantausing a reverse-genetics approach revealed a complex, molecular tug-of-war between host and virus. Structural mimicry and diversifying selection—hallmarks of host-pathogen interactions—were identified within host and viral binding interfaces predicted by our models. These results illuminate the functional diversity of the PLRV-host protein interaction network and demonstrate the usefulness of PIR technology for precision mapping of functional host-pathogen protein interaction topologies.IMPORTANCEThe exterior shape of a plant virus and its interacting host and insect vector proteins determine whether a virus will be transmitted by an insect or infect a specific host. Gaining this information is difficult and requires years of experimentation. We used protein interaction reporter (PIR) technology to illustrate how viruses exploit host proteins during plant infection. PIR technology enabled our team to precisely describe the sites of functional virus-virus, virus-host, and host-host protein interactions using a mass spectrometry analysis that takes just a few hours. Applications of PIR technology in host-pathogen interactions will enable researchers studying recalcitrant pathogens, such as animal pathogens where host proteins are incorporated directly into the infectious agents, to investigate how proteins interact during infection and transmission as well as develop new tools for interdiction and therapy.

Variable-Temperature Native Mass Spectrometry for Studies of Protein Folding, Stabilities, Assembly, and Molecular Interactions

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Arthur Laganowsky ◽  
David E. Clemmer ◽  
David H. Russell
Keyword(s):  
Mass Spectrometry ◽  
Dynamic Range ◽  
Protein Complexes ◽  
Noncovalent Interactions ◽  
Variable Temperature ◽  
Regulatory Protein ◽  
Conformational Dynamics ◽  
Native Mass Spectrometry ◽  
Annual Review ◽  
Publication Date

The structures and conformational dynamics of proteins, protein complexes, and their noncovalent interactions with other molecules are controlled specifically by the Gibbs free energy (entropy and enthalpy) of the system. For some organisms, temperature is highly regulated, but the majority of biophysical studies are carried out at room, nonphysiological temperature. In this review, we describe variable-temperature electrospray ionization (vT-ESI) mass spectrometry (MS)-based studies with unparalleled sensitivity, dynamic range, and selectivity for studies of both cold- and heat-induced chemical processes. Such studies provide direct determinations of stabilities, reactivities, and thermodynamic measurements for native and non-native structures of proteins and protein complexes and for protein–ligand interactions. Highlighted in this review are vT-ESI-MS studies that reveal 40 different conformers of chymotrypsin inhibitor 2, a classic two-state (native → unfolded) unfolder, and thermochemistry for a model membrane protein system binding lipid and its regulatory protein. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

LOPIT-DC: A simpler approach to high-resolution spatial proteomics

2018 ◽  
Author(s):  
Aikaterini Geladaki ◽  
Nina Kočevar Britovšek ◽  
Lisa M. Breckels ◽  
Tom S. Smith ◽  
Claire M. Mulvey ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Protein Complexes ◽  
Subcellular Localisation ◽  
Proteomics Data ◽  
Large Protein ◽  
Subcellular Resolution ◽  
First Time ◽  
Human Dataset

AbstractHyperplexed Localisation of Organelle Proteins by Isotope Tagging (hyperLOPIT) is a well-established method for studying protein subcellular localisation in complex biological samples. As a simpler alternative we developed a second workflow named Localisation of Organelle Proteins by Isotope Tagging after Differential ultraCentrifugation (LOPIT-DC) which is faster and less resource-intensive. We present the most comprehensive high-resolution mass spectrometry-based human dataset to date and deliver a flexible set of subcellular proteomics protocols for sample preparation and data analysis. For the first time, we methodically compare these two different mass spectrometry-based spatial proteomics methods within the same study and also apply QSep, the first tool that objectively and robustly quantifies subcellular resolution in spatial proteomics data. Using both approaches we highlight suborganellar resolution and isoform-specific subcellular niches as well as the locations of large protein complexes and proteins involved in signalling pathways which play important roles in cancer and metabolism. Finally, we showcase an extensive analysis of the multilocalising proteome identified via both methods.

scholarly journals Strategies for understanding dynamic, personalized profiles of host-derived proteins and microbes from human stool

2019 ◽  
Author(s):  
Ellen Casavant ◽  
Les Dethlefsen ◽  
Kris Sankaran ◽  
Daniel Sprockett ◽  
Susan Holmes ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Protein Profile ◽  
Host Protein ◽  
Host Proteins ◽  
Protein Marker ◽  
Gastrointestinal Health ◽  
Wide Range ◽  
Subject Variability ◽  
Human Stool ◽  
Over Time

AbstractMeasuring host proteins through noninvasive stool-based assays opens new avenues for characterizing states of gastrointestinal health. However, the extent to which these proteins vary over time and between healthy subjects is poorly characterized. Here, we characterize technical and biological sources of variability in mass spectrometry-based measurements of host proteins in stool. We identify the proteins that most vary over time within an individual, and among different individuals. Finally, we examine and compare temporal and inter-individual variation in host protein and bacterial taxonomic profiles of the same fecal specimens. To address these issues, five self-reported healthy individuals were each sampled eight times over four weeks. First, we demonstrate that mass spectrometry-based identification and label-free quantification of stool proteins exhibit non-significant variability (p>0.05) between both technical and preparative replicates for a subset of 78 proteins, supporting the utility of this method for biomarker measurement. Second, although 13 human stool proteins varied significantly in relative abundance over time within individuals, 58 proteins varied significantly (at least four-fold) between subjects. The average pair-wise difference between individuals was greater than the average within-subject difference for both the proteome and microbiome datasets (p<0.0001). Fecal host proteins, like the traditional fecal protein marker, calprotectin, unambiguously pointed to innate and adaptive immune responses. For example, one subject’s fecal protein profile suggested a sub-clinical inflammatory state. From these data, we conclude that host-centric protein measurements in stool reveal a wide range of variation during states of apparent health, and add a valuable complementary insight into host-microbiota relationships.IMPORTANCEHuman proteins in stool hold untapped potential for characterizing gastrointestinal health. To fully harness this potential and create a baseline of healthy stool protein abundances and identifications, it will be important to establish the extent to which these proteins might vary in the absence of disease. This study quantifies the major sources of variation in stool protein abundance data. We assessed technical, preparative, temporal, and inter-subject variability of human protein abundances in stool and found that among these sources, differences between subjects accounted for the greatest amount of variation, followed by temporal differences, and then technical factors. Our paired microbiome analysis found matching patterns of temporal and inter-subject variability. By characterizing multiple variance parameters in host stool protein abundances, our analysis helps to contextualize a wide range of future disease-focused stool studies as well as elucidate host-microbe interactions.

scholarly journals Proteome-wide cross-linking mass spectrometry to identify specific virus capsid-host interactions between tick-borne encephalitis virus and neuroblastoma cells

2021 ◽  
Author(s):  
Sarah V Barrass ◽  
Lauri I A Pulkkinen ◽  
Olli Vapalahti ◽  
Suvi Kuivanen ◽  
Maria Anastasina ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
Neuroblastoma Cells ◽  
Encephalitis Virus ◽  
Host Protein ◽  
Cross Linking ◽  
Host Proteins ◽  
Host Interactions ◽  
Tick Borne Encephalitis ◽  
Tick Borne Encephalitis Virus

Virus-host protein-protein interactions are central to viral infection, but are challenging to identify and characterise, especially in complex systems involving intact viruses and cells. In this work, we demonstrate a proteome-wide approach to identify virus-host interactions using chemical cross-linking coupled with mass spectrometry. We adsorbed tick-borne encephalitis virus onto metabolically-stalled neuroblastoma cells, covalently cross-linked interacting virus-host proteins, and performed limited proteolysis to release primarily the surface-exposed proteins for identification by mass spectrometry. Using the intraviral protein cross-links as an internal control to assess cross-link confidence levels, we identified 22 high confidence unique intraviral cross-links and 59 high confidence unique virus-host protein-protein interactions. The identified host proteins were shown to interact with eight distinct sites on the outer surface of the virus. Notably, we identified an interaction between the substrate-binding domain of heat shock protein family A member 5, an entry receptor for four related flaviviruses, and the hinge region of the viral envelope protein. We also identified host proteins involved in endocytosis, cytoskeletal rearrangement, or located in the cytoskeleton, suggesting that entry mechanisms for tick-borne encephalitis virus could include both clathrin-mediated endocytosis and macropinocytosis. Additionally, cross-linking of the viral proteins showed that the capsid protein forms dimers within tick-borne encephalitis virus, as previously observed with purified C proteins for other flaviviruses. This method enables the identification and mapping of transient virus-host interactions, under near-physiological conditions, without the need for genetic manipulation.

Evaluation of Acquisition Modes for the Quantitative Analysis of Cross-Linked Peptides by Targeted and Untargeted Mass Spectrometry

2020 ◽  
Author(s):  
Hannah Britt ◽  
Tristan Cragnolini ◽  
Suniya Khatun ◽  
Abubakar Hatimy ◽  
Juliette James ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Dynamic Range ◽  
Temporal Dynamics ◽  
Protein Complexes ◽  
Isotopic Labeling ◽  
Single Experiment ◽  
Data Independent Acquisition ◽  
Quantitative Metrics ◽  
Parallel Reaction Monitoring ◽  
Further Development

<div> <div> <p>Cross-linking mass spectrometry (XL-MS) is a structural biology technique that can provide insights into the structure and interactions of proteins and their complexes, especially those that cannot be easily assessed by other methods. Quantitative XL-MS has the potential to probe the structural and temporal dynamics of protein complexes; however, it requires further development. Until recently, quantitative XL-MS has largely relied upon isotopic labeling and data dependent acquisition (DDA) methods, limiting the number of biological samples that can be studied in a single experiment. Here, the acquisition modes available on an ion mobility (IM) enabled QToF mass spectrometer are evaluated for the quantitation of cross-linked peptides, eliminating the need for isotopic labels and thus expanding the number of comparable studies that can be conducted in parallel. Workflows were optimized using metabolite and peptide standards analyzed in biological matrices, facilitating modelling of the data and addressing linearity issues, which allow for significant increases in dynamic range. Evaluation of the DDA acquisition method commonly used in XL-MS studies indicated consistency issues between technical replicates and reduced performance in quantitative metrics. On the contrary, data independent acquisition (DIA) and parallel reaction monitoring (PRM) modes proved more robust for analyte quantitation. Mobility enabled modes exhibited an improvement in sensitivity due to the added dimension of separation, and a simultaneous reduction in dynamic range, which was largely recovered by correction methods. Hi[3] and probabilistic quantitation methods were successfully applied to the DIA data, determining the molar amounts of cross-linked peptides relative to their linear counterparts.</p></div></div>

scholarly journals From Affinity to Proximity Techniques to Investigate Protein Complexes in Plants

2021 ◽  
Vol 22 (13) ◽  
pp. 7101
Author(s):  
Sandra M. Kerbler ◽  
Roberto Natale ◽  
Alisdair R. Fernie ◽  
Youjun Zhang
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
Hydrophobic Interactions ◽  
Protein Complexes ◽  
Specific Binding ◽  
Affinity Purification ◽  
Interaction Network ◽  
Unicellular Eukaryote ◽  
Bait Protein ◽  
Advantages And Disadvantages

The study of protein–protein interactions (PPIs) is fundamental in understanding the unique role of proteins within cells and their contribution to complex biological systems. While the toolkit to study PPIs has grown immensely in mammalian and unicellular eukaryote systems over recent years, application of these techniques in plants remains under-utilized. Affinity purification coupled to mass spectrometry (AP-MS) and proximity labeling coupled to mass spectrometry (PL-MS) are two powerful techniques that have significantly enhanced our understanding of PPIs. Relying on the specific binding properties of a protein to an immobilized ligand, AP is a fast, sensitive and targeted approach used to detect interactions between bait (protein of interest) and prey (interacting partners) under near-physiological conditions. Similarly, PL, which utilizes the close proximity of proteins to identify potential interacting partners, has the ability to detect transient or hydrophobic interactions under native conditions. Combined, these techniques have the potential to reveal an unprecedented spatial and temporal protein interaction network that better understands biological processes relevant to many fields of interest. In this review, we summarize the advantages and disadvantages of two increasingly common PPI determination techniques: AP-MS and PL-MS and discuss their important application to plant systems.

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