Reviews & Perspectives
Deciphering Spatial Protein–Protein Interactions in Brain Using Proximity Labeling
In Brief PL has emerged as a powerful tool to identify proteomes in distinct cell types in brain as well as proteomes and protein–protein interaction networks in structures difficult to isolate, such as the synaptic cleft, axonal projections, or astrocyte–neuron junctions. Here, we review recent advances in PL methods and their application to neurobiology.An Expanding Repertoire of Protein Acylations
In Brief In this work, we give a general overview of the 12 main protein acylations, also including novel acylations, such as benzoylation and 2-hydroxyisobutyrylation. We summarize the recent advances in protein acylation, mainly focus on their substrates, enzymes, biological functions, and novel detecting methods and related diseases, especially in cancer. We believe that the review will provide an unprecedented and comprehensive view of protein acylations and bring important reference significance for future research.Subcellular Transcriptomics and Proteomics: A Comparative Methods Review
In Brief The interior of the cell is molecularly crowded. Its compartmentalization within organelles enables the regulation of biochemical processes and allows multifunctionality of proteins and RNAs. Subcellular information can thus give insights into the function of these biomolecules. Multiple techniques to measure such information have been established, with ever-increasing throughput and sensitivity. These techniques are covered in this review, and demonstrating their application is providing valuable insights into cellular biology, such as aiding our understanding of single-cell heterogeneity and posttranslational modifications.Neuroproteomics of the Synapse: Subcellular Quantification of Protein Networks and Signaling Dynamics
In Brief Advancements in MS-based proteomics have increased the study of synaptic proteins using neuroproteomics. The development of proximity, genetic labeling and bio-orthogonal amino acid labeling approaches now allow for the study of synaptic protein–protein interactions and protein signaling dynamics. In this review, we highlight studies from the last 5 years, with a focus on synapse structure, composition, functioning, or signaling and finally discuss some recent developments that could further advance the field of neuroproteomics.Proteomics-Based Insights Into the SARS-CoV-2–Mediated COVID-19 Pandemic: A Review of the First Year of Research
In Brief SARS-CoV-2, the betacoronavirus that caused the COVID-19 pandemic, became a major source of human disease and death in 2020. The fundamental constituents of a virus being its genome and proteome, characterizing the proteome is essential to understanding its biology. In this review article, we survey the proteomics literature from the first year of the COVID-19 pandemic, including protein–protein interaction studies, post-translational modification studies, and work using proteomics technologies to probe host response, which collectively inform efforts to ameliorate the pandemic.MS-Based HLA-II Peptidomics Combined With Multiomics Will Aid the Development of Future Immunotherapies
In Brief Although challenges remain in leveraging MS-based HLA-II peptidomics, investigations into the interplay between disease pathologies and the presentation of HLA-II peptides to CD4+ T cells will enable the development of future immunotherapies. In this Review article, we discuss our current understanding of HLA-II peptidomics and outstanding questions in the field and how MS-based innovations will enable us to fill knowledge gaps and help improve our ability to select HLA-II-presented antigens as targets for personalized immunotherapies.Decoding Post-Translational Modification Crosstalk With Proteomics
In Brief We provide an overview of current experimental and computational proteomic methods, as well as a perspective on emerging technologies to study PTM crosstalk.Uncovering the Depths of the Human Proteome: Antibody-based Technologies for Ultrasensitive Multiplexed Protein Detection and Quantification
In Brief Probing the human plasma proteome is attractive for biomarker and drug target discovery. Recent breakthroughs in multiplex proteomics technologies enable the simultaneous and sensitive quantification of thousands of proteins in biofluids. We provide a comprehensive guide to the methodologies, performance, advantages, and disadvantages of established and emerging technologies for the multiplexed ultrasensitive measurement of proteins. Gaining knowledge on these innovations is crucial for choosing the right multiplexed proteomics tool to critically complement traditional proteomics methods.An Introduction to Advanced Targeted Acquisition Methods
In Brief The analytical power of targeted proteomics depends on how efficiently the mass spectrometer detects target peptides. A number of “smart” acquisition approaches have been developed that enable more targets per run and improve analytical performance such as sensitivity, specificity, and quantitative accuracy. This review provides an introduction to these methods and highlights their inherent strengths and weaknesses.Recent Advances in Software Tools for More Generic and Precise Intact Glycopeptide Analysis
In Brief This article provides a systematic review of the most recent MS-based strategies and corresponding software tools for the analysis of intact glycopeptides, particularly intact N-glycopeptides, reported in the last decade, including the process of identifying N-glycopeptides from MS data, the existing methods of MS data acquisition and interpretation, the quality control methods, the display of results, and the software applications.Recent Advances in Analytical Approaches for Glycan and Glycopeptide Quantitation
In Brief Recent years have seen an explosion in novel strategies for quantitative glycomics and glycoproteomics. Whether through metabolic incorporation of stable isotopes, deposition of custom isotopic labels, or high-throughput isobaric chemical tags, these numerous novel strategies provide ease of access to glycomic and glycoproteomic investigation. This review highlights the recent innovations in labeling methods, label-free strategies, acquisition modes, and bioinformatic tools for glycan and glycopeptide quantitation, while providing critical evaluations and technical considerations to enable effective analysis.The Role of Data-Independent Acquisition for Glycoproteomics
In Brief As a highly abundant and diverse post-translational modification, protein glycosylation is challenging to characterize in various approaches including MS. In MS-based proteomics, data-independent acquisition (DIA) has been advanced rapidly and showed outstanding analytical performances. DIA now started to be applied in different facets of glycoproteomics, including deglycosylated and intact N-linked and O-linked glycopeptides, and screening of oxonium ions. We summarized current applications of DIA in glycoproteomics and discussed its limitations and perspectives.Chromatin Proteomics to Study Epigenetics — Challenges and Opportunities
In Brief MS-based analysis of chromatin has emerged as a powerful tool to identify proteins associated with gene regulation. Total chromatin isolated from cells can be directly analyzed using MS, further fractionated into transcriptionally active and inactive chromatin, enriched for specific compartment or regions, and potentially used for single-locus isolation. This review highlights recent advances and discusses current challenges that should be addressed to further advance the field of chromatin proteomics.Calculating Glycoprotein Similarities From Mass Spectrometric Data
In Brief To understand the roles of glycoproteins in biological processes, it is necessary to quantify the changes that occur to glycosylation at individual sites and to the whole molecule. That glycoprotein glycosylation is inherently heterogeneous means that the distribution of glycoforms at each glycosite must be quantified in order to inform calculation of molecular similarities. We review analytical and statistical methods for determining glycoprotein molecular similarities from glycoproteomics data.Glycomics, Glycoproteomics, and Glycogenomics: An Inter-Taxa Evolutionary Perspective
In Brief This review article i) assesses the utility of current glycomic, glycoproteomic, and glycogenomic methods to characterize protein glycosylation in less-well-studied eukaryotes; ii) assembles a plausible evolutionary lineage of eukaryotic glycan–protein linkages from the last eukaryotic common ancestor through protists to multicellular plants, invertebrates, and vertebrates; and iii) highlights the diversity of peripheral glycan specializations and modifications with an emphasis on available information from diverse protist kingdoms and invertebrate animals.Developments in Mass Spectrometry for Glycosaminoglycan Analysis: A Review
In Brief Glycosaminoglycans (GAGs) participate in a variety of biological functions and have a multitude of medicinal properties. Due to their non template driven biosynthesis, GAGs are produced as nonuniform complex mixtures. Mass spectrometry paired with on-line separation techniques has been utilized to determine the composition of these complex mixtures. Advances in tandem mass spectrometry have also made determining sequence information such as sulfation location and C-5 epimerization possible. This review covers recent developments in the analysis of GAGs using mass spectrometry.The Peptide Vaccine of the Future
In Brief Therapeutic peptide-based vaccination approaches for the treatment of cancer patients have shown first glimmers of success. However, to achieve broad clinical efficacy and implement peptide vaccinations in the standard treatment of cancer patients future peptide vaccines need further optimization in terms of target antigen selection, adjuvant choice, vaccination schedules, delivery routes, biomarkers, and combinatorial drugs.Methods for Enrichment and Assignment of N-Acetylglucosamine Modification Sites
In Brief This review article summarizes methods for O-GlcNAc enrichment and different mass spectrometric approaches for acquiring data on modified peptides and describes software strategies for analyzing data, including the challenges of reliably identifying modification sites and differentiating between other potential HexNAc modifications. It then presents a new dataset to exemplify what is currently achievable.A Pragmatic Guide to Enrichment Strategies for Mass Spectrometry–Based Glycoproteomics
In Brief Interest in mass spectrometry–based glycoproteomics analysis is increasing because of recent advances in instrumentation and data analysis tools. Such studies can provide a wealth of information across a wide spectrum of glycan classes and biological systems. However, many studies require the choice of an enrichment strategy for glycosylated species prior to analysis to obtain the maximum amount of analytical information. Here, common enrichment strategies are reviewed with strengths and weaknesses, and the practical considerations for various methods are discussed.Meta-heterogeneity: Evaluating and Describing the Diversity in Glycosylation Between Sites on the Same Glycoprotein
In Brief Diversity in protein glycosylation can be described in terms of micro-heterogeneity and macro-heterogeneity, respectively, referring to the variation and occupancy of glycans at a given glycosylation site. However, these terms are not sufficient to describe a higher level of regulation when proteins are multiply glycosylated. For this, we propose the term meta-heterogeneity: variation in glycosylation across multiple sites of a given glycoprotein. In this review, we describe several remarkable examples of glycoprotein meta-heterogeneity and underline the need for its investigation.Accelerating the Field of Epigenetic Histone Modification Through Mass Spectrometry–Based Approaches
In Brief Histone post-translational modifications play essential roles in the epigenetic regulation of chromatin-related functions. Because of its high throughput, accuracy, and flexibility, mass spectrometry has emerged as a powerful tool in the epigenetic field. In this review, we describe the contributions of mass spectrometry–based proteomics in combination with distinct labeling strategies and various biological techniques to understand the roles of histone post-translational modifications and how they regulate chromatin function.Proteome Turnover in the Spotlight: Approaches, Applications, and Perspectives
In Brief In this review, we outline historical and current approaches to measure the kinetics of protein turnover on a proteome-wide scale in both steady-state and dynamic systems, with an emphasis on metabolic tracing using stable isotope–labeled amino acids. In addition, we highlight important considerations for designing proteome turnover experiments, key biological findings regarding the conserved principles of proteome turnover regulation, and future perspectives for both technological and biological investigations.Single-cell Proteomics: Progress and Prospects
Single-cell proteomics capabilities have the potential to transform biomedical research and enable understanding of biological systems with a new level of granularity. Recent advances in sample processing, separations and MS instrumentation now make it possible to quantify >1000 proteins from individual mammalian cells.Proteomics and Metaproteomics Add Functional, Taxonomic and Biomass Dimensions to Modeling the Ecosystem at the Mucosal-luminal Interface
Proteomics and metaproteomics are important tools for studying the spatiotemporal heterogeneous ecosystem in our gut. We review strategies and their applications to gut ecology studies, such as building a dynamical model of the MLI.Organellar Maps Through Proteomic Profiling – A Conceptual Guide
Protein subcellular localization is highly regulated and critical for protein function. Spatial proteomics aims at capturing the localization dynamics of all proteins expressed in a given cell type. Among different approaches, organellar mapping through proteomic profiling stands out as the only method capable of determining the subcellular localizations of thousands of proteins in a single experiment. Importantly, it can also detect movements of proteins between subcellular compartments, providing an unbiased systems analysis tool for investigating physiological and pathological cellular processes.
