scholarly journals The Plant PTM Viewer, a central resource exploring plant protein modifications. From site-seeing to protein function

2018 ◽  
Author(s):  
Patrick Willems ◽  
Alison Horne ◽  
Sofie Goormachtig ◽  
Ive De Smet ◽  
Alexander Botzki ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Posttranslational Modifications ◽  
Protein Function ◽  
Protein Sequences ◽  
Specific Protein ◽  
Specific Information ◽  
Active Site Residues ◽  
Functional Protein ◽  
Protein Modifications ◽  
Modern Mass

SUMMARYPosttranslational modifications (PTMs) of proteins are central in any kind of cellular signaling. Modern mass spectrometry technologies enable comprehensive identification and quantification of various PTMs. Given the increased number and types of mapped protein modifications, a database is necessary that simultaneouly integrates and compares site-specific information for different PTMs, especially in plants for which the available PTM data are poorly catalogued. Here, we present the Plant PTM Viewer (http://www.psb.ugent.be/PlantPTMViewer), an integrative PTM resource that comprises approximately 200,000 PTM sites for 17 types of protein modifications in plant proteins from five different species. The Plant PTM Viewer provides the user with a protein sequence overview in which the experimentally evidenced PTMs are highlighted together with functional protein domains or active site residues. The PTM sequence search tool can query PTM combinations in specific protein sequences, whereas the PTM BLAST tool searches for modified protein sequences to detect conserved PTMs in homologous sequences. Taken together, these tools facilitate to assume the role and potential interplay of PTMs in specific proteins or within a broader systems biology context. The Plant PTM Viewer is an open repository that allows submission of mass spectrometry-based PTM data to remain at pace with future PTM plant studies.

scholarly journals Discovery and Interrogation of Functional Protein Modifications by Hotspot Thermal Profiling

2019 ◽  
Author(s):  
Jun X. Huang ◽  
Gihoon Lee ◽  
Raymond E. Moellering
Keyword(s):  
Posttranslational Modifications ◽  
Protein Function ◽  
Cell Types ◽  
Specific Protein ◽  
Live Cells ◽  
Functional Protein ◽  
Site Specific ◽  
Native Proteins ◽  
Thermal Profiling ◽  
Multiple Samples

Abstract Hundreds of protein posttranslational modification types have been reported across diverse organisms, however we still lack methods to systematically predict, or even prioritize, which modification sites may perturb protein function under specific cellular contexts. This protocol describes a method to detect the effects of site-specific protein phosphorylation on the thermal stability of thousands of native proteins in live cells. This mass spectrometry-based protocol measures shifts in overall protein stability in response to site-specific phosphorylation sites. The resulting dataset can enable discovery of intrinsic changes to protein structure as well as extrinsic changes to protein-protein, and protein-metabolite interactions, and can help prioritize site-specific study in a high-throughput and unbiased fashion. This approach takes several days complete, can be performed with multiple samples in parallel and is applicable to diverse organisms, cell types and posttranslational modifications.

scholarly journals Pyntheon: A Functional Analysis Framework for Protein Modifications and Mutations of 83 Model Organisms

2019 ◽  
Author(s):  
Ahmed Arslan
Keyword(s):  
Posttranslational Modifications ◽  
Protein Modification ◽  
Model Organisms ◽  
Analysis Framework ◽  
Proteomics Data ◽  
Functional Protein ◽  
Protein Modifications ◽  
Community Of Researchers ◽  
Protein Mutations ◽  
The Impact

AbstractMotivationPosttranslational modifications (PTMs) modulate proteins activity depending on the dynamics of cellular conditions, in the highly regulated processes that control the reversible nature of these modifications and a cellular state. Due to the unique importance of PTMs, a number of resources are available to analyze the protein modification data for different organisms. These databases are quite informative on a limited number of popular organisms, mostly human and yeast. However there has not been a single database to date that makes it possible to analyze the modified protein residue data for up to 83 model organisms. Moreover, there are limited resources that rely on both protein mutations and modifications in evaluating a phenotype.ResultsI am presenting a comprehensive python tool Pyntheon that enables users to analyze protein modifications and mutations data. This resource can be used in different ways to know: (i) if the proteins of interest have modifications and (ii) if the modified residues overlap with mutated sites. Additional functions include, analyzing if a PTM-site is present in a functional protein region, like domain and structural regions. In summary, Pyntheon makes it possible for a larger community of researchers to evaluate their curated proteomics data and interpret the impact of mutations on phenotypes.ConclusionPyntheon has multifold functions that can help analyzing the protein mutations impact on the modified residues for a large number of popular model organisms.Code-Availabilityhttps://github.com/AhmedArslan/[email protected]

scholarly journals Systematic Identification of Protein Phosphorylation-Mediated Interactions

2020 ◽  
Author(s):  
Brendan M. Floyd ◽  
Kevin Drew ◽  
Edward M. Marcotte
Keyword(s):  
Mass Spectrometry ◽  
Protein Phosphorylation ◽  
Protein Interactions ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Specific Protein ◽  
Mass Spectrometry Data ◽  
Size Exclusion ◽  
Functional Protein

ABSTRACTProtein phosphorylation is a key regulatory mechanism involved in nearly every eukaryotic cellular process. Increasingly sensitive mass spectrometry approaches have identified hundreds of thousands of phosphorylation sites but the functions of a vast majority of these sites remain unknown, with fewer than 5% of sites currently assigned a function. To increase our understanding of functional protein phosphorylation we developed an approach for identifying the phosphorylation-dependence of protein assemblies in a systematic manner. A combination of non-specific protein phosphatase treatment, size-exclusion chromatography, and mass spectrometry allowed us to identify changes in protein interactions after the removal of phosphate modifications. With this approach we were able to identify 316 proteins involved in phosphorylation-sensitive interactions. We recovered known phosphorylation-dependent interactors such as the FACT complex and spliceosome, as well as identified novel interactions such as the tripeptidyl peptidase TPP2 and the supraspliceosome component ZRANB2. More generally, we find phosphorylation-dependent interactors to be strongly enriched for RNA-binding proteins, providing new insight into the role of phosphorylation in RNA binding. By searching directly for phosphorylated amino acid residues in mass spectrometry data, we identified the likely regulatory phosphosites on ZRANB2 and FACT complex subunit SSRP1. This study provides both a method and resource for obtaining a better understanding of the role of phosphorylation in native macromolecular assemblies.

scholarly journals Single-molecule and Single-cell Approaches in Molecular Bioengineering

2020 ◽  
Vol 74 (9) ◽  
pp. 704-709
Author(s):  
Michael A. Nash
Keyword(s):  
Single Molecule ◽  
Protein Function ◽  
High Throughput Screening ◽  
Protein Sequences ◽  
Structural Features ◽  
Functional Protein ◽  
Molecular Systems ◽  
Measurement Tools ◽  
And Function ◽  
Control Protein

Protein sequences inhabit a discrete set in macromolecular space with incredible capacity to treat human disease. Despite our ability to program and manipulate protein sequences, the vast majority of protein development efforts are still done heuristically without a unified set of guiding principles. This article highlights work in understanding biophysical stability and function of proteins, developing new biophysical measurement tools and building high-throughput screening platforms to explore functional protein sequences. We highlight two primary areas. First, molecular biomechanics is a subfield concerned with the response of proteins to mechanical forces, and how we can leverage mechanical force to control protein function. The second subfield investigates the use of polymers and hydrogels in protein engineering and directed evolution in pursuit of new molecular systems with therapeutic applications. These two subdisciplines complement each other by shedding light onto sequence and structural features that can be used to impart stability into therapeutic proteins.

scholarly journals Discovery of protein modifications using high resolution differential mass spectrometry proteomics

2020 ◽  
Author(s):  
Paolo Cifani ◽  
Zhi Li ◽  
Danmeng Luo ◽  
Mark Grivainis ◽  
Andrew M. Intlekofer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Open Source ◽  
High Resolution Mass Spectrometry ◽  
Peptide Identification ◽  
High Specificity ◽  
Functional Protein ◽  
Protein Modifications ◽  
Specificity And Sensitivity ◽  
Spectral Alignment

SummaryRecent studies have revealed diverse amino acid, post-translational and non-canonical modifications of proteins in diverse organisms and tissues. However, their unbiased detection and analysis remain hindered by technical limitations. Here, we present a spectral alignment method for the identification of protein modifications using high-resolution mass spectrometry proteomics. Termed SAMPEI for Spectral Alignment-based Modified PEptide Identification, this open-source algorithm is designed for the discovery of functional protein and peptide signaling modifications, without prior knowledge of their identities. Using synthetic standards and controlled chemical labeling experiments, we demonstrate its high specificity and sensitivity for the discovery of sub-stoichiometric protein modifications in complex cellular extracts. SAMPEI mapping of mouse macrophage differentiation revealed diverse post-translational protein modifications, including distinct forms of cysteine itaconatylation. SAMPEI’s robust parameterization and versatility are expected to facilitate the discovery of biological modifications of diverse macromolecules. SAMPEI is implemented as a Python package, and is available open-source from BioConda and GitHub (https://github.com/FenyoLab/SAMPEI).

scholarly journals Expanding functional protein sequence space using generative adversarial networks

2019 ◽  
Author(s):  
Donatas Repecka ◽  
Vykintas Jauniskis ◽  
Laurynas Karpus ◽  
Elzbieta Rembeza ◽  
Jan Zrimec ◽  
...  
Keyword(s):  
Protein Design ◽  
Sequence Space ◽  
Protein Sequence ◽  
Protein Function ◽  
De Novo ◽  
Protein Sequences ◽  
Generative Adversarial Networks ◽  
Functional Protein ◽  
Generative Adversarial Network

ABSTRACTDe novo protein design for catalysis of any desired chemical reaction is a long standing goal in protein engineering, due to the broad spectrum of technological, scientific and medical applications. Currently, mapping protein sequence to protein function is, however, neither computationionally nor experimentally tangible 1,2. Here we developed ProteinGAN, a specialised variant of the generative adversarial network 3 that is able to ‘learn’ natural protein sequence diversity and enables the generation of functional protein sequences. ProteinGAN learns the evolutionary relationships of protein sequences directly from the complex multidimensional amino acid sequence space and creates new, highly diverse sequence variants with natural-like physical properties. Using malate dehydrogenase as a template enzyme, we show that 24% of the ProteinGAN-generated and experimentally tested sequences are soluble and display wild-type level catalytic activity in the tested conditions in vitro, even in highly mutated (>100 mutations) sequences. ProteinGAN therefore demonstrates the potential of artificial intelligence to rapidly generate highly diverse novel functional proteins within the allowed biological constraints of the sequence space.

scholarly journals Small Changes Huge Impact: The Role of Protein Posttranslational Modifications in Cellular Homeostasis and Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Tejaswita M. Karve ◽  
Amrita K. Cheema
Keyword(s):  
Posttranslational Modifications ◽  
Protein Function ◽  
A Priori ◽  
Decisive Role ◽  
Amino Acid Residues ◽  
Cellular Functions ◽  
Diverse Range ◽  
Protein Modifications ◽  
Huge Impact ◽  
Life Threatening

Posttranslational modifications (PTMs) modulate protein function in most eukaryotes and have a ubiquitous role in diverse range of cellular functions. Identification, characterization, and mapping of these modifications to specific amino acid residues on proteins are critical towards understanding their functional significance in a biological context. The interpretation of proteome data obtained from the high-throughput methods cannot be deciphered unambiguously without a priori knowledge of protein modifications. An in-depth understanding of protein PTMs is important not only for gaining a perception of a wide array of cellular functions but also towards developing drug therapies for many life-threatening diseases like cancer and neurodegenerative disorders. Many of the protein modifications like ubiquitination play a decisive role in various drug response(s) and eventually in disease prognosis. Thus, many commonly observed PTMs are routinely tracked as disease markers while many others are used as molecular targets for developing target-specific therapies. In this paper, we summarize some of the major, well-studied protein alterations and highlight their importance in various chronic diseases and normal development. In addition, other promising minor modifications such as SUMOylation, observed to impact cellular dynamics as well as disease pathology, are mentioned briefly.

The challenge of detecting modifications on proteins

2020 ◽  
Vol 64 (1) ◽  
pp. 135-153 ◽  
Author(s):  
Lauren Elizabeth Smith ◽  
Adelina Rogowska-Wrzesinska
Keyword(s):  
Mass Spectrometry ◽  
Protein Function ◽  
Chemical Properties ◽  
Lysine Acetylation ◽  
Mass Determination ◽  
Post Translational Modifications ◽  
Site Specific ◽  
The Common

Abstract Post-translational modifications (PTMs) are integral to the regulation of protein function, characterising their role in this process is vital to understanding how cells work in both healthy and diseased states. Mass spectrometry (MS) facilitates the mass determination and sequencing of peptides, and thereby also the detection of site-specific PTMs. However, numerous challenges in this field continue to persist. The diverse chemical properties, low abundance, labile nature and instability of many PTMs, in combination with the more practical issues of compatibility with MS and bioinformatics challenges, contribute to the arduous nature of their analysis. In this review, we present an overview of the established MS-based approaches for analysing PTMs and the common complications associated with their investigation, including examples of specific challenges focusing on phosphorylation, lysine acetylation and redox modifications.

Preparation and Characterization of β-glucosidase Films for Stabilization and Handling in Dry Configurations

2020 ◽  
Vol 21 (8) ◽  
pp. 741-747
Author(s):  
Liguang Zhang ◽  
Yanan Shen ◽  
Wenjing Lu ◽  
Lengqiu Guo ◽  
Min Xiang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Protein Function ◽  
Protein Stabilization ◽  
Functional Protein ◽  
Elongation At Break ◽  
Gelatin Films ◽  
The Stability ◽  
And Function ◽  
General Method

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Method: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Result: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.

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