Protein–protein interaction networks articles within Nature Communications

Protein-protein interactions underlie all aspects of a viral infection. Here the authors employ a pan-viral approach for systematic identification of motif-mediated interactions between viral and human proteins and show that the information can be used to find targets for antiviral drug development.

Maps of protein-protein interactions (PPIs) help identify new components of pathways, complexes, and processes. In this work, state-of-the-art methods are used to identify binary Drosophila PPIs, generating broadly useful physical and data resources.

The 16p11.2 duplication confers risk for autism and schizophrenia, but the disease mechanisms are unknown. Here, the authors use proteomics to show dysregulation of synaptic and epilepsy-associated protein networks in the cortex of model mice, and demonstrate that correcting Prrt2 gene dosage rescues circuit hypersynchrony and behavioural phenotypes.

Here the authors establish the SPOC domain as a universal reader of the RNA Pol II CTD code and a versatile reader of phosphoserine marks found in co- and post-transcriptional regulators such as m6A writer and reader proteins.

Protein phosphorylation is a ubiquitous post-translational modification used to regulate cellular processes and proteome architecture by modulating protein-protein interactions. Here the authors optimize genetically encoded phosphothreonine to study the regulation of CHK2 kinase using large-scale DNA arrays that enable phosphoproteome expression techniques to identify sitespecific overlap between CHK2 substrates and 14-3-3 interactions.

Specificity in signaling activated by receptor tyrosine kinases is typically attributed to characteristics of their intracellular domains. Here, the authors demonstrate that an extracellular receptor sequence motif controls intracellular signaling as a result of extracellular glycan interactions.

In patients with melanoma, increased RAS/mitogen-activated protein kinase (MAPK) pathway activity is known to drive chemotherapy resistance. Here, the authors identify CDK12 as a downstream effector of the RAS/MAPK pathway and therapeutic target which mediates chemotherapy resistance through increased expression of DNA repair associated genes.

The slit-diaphragm is a cellular junction that is crucial for blood filtration in the kidney. Kocylowski et al. show that the junction-spanning components are embedded in a protein network for dynamic control of filtration; network disturbance leads to severe filtration defects with proteinuria.

Protein complexes play a decisive role for lysosomal function. Here, the authors use cross-linking mass spectrometry and integrative modeling to investigate lysosomes and early endosomes; characterizing protein interactions, structures, and the cargo of flotillin-mediated endocytosis.

The insulin signalling cascade can be inhibited by phosphatases, including Ser/Thr protein phosphatase 2A (PP2A). Here the authors show that Alpha4, a regulator of the PP2A catalytic subunit, modulates insulin receptor tyrosine phosphorylation via the YBX-1/PTP1B pathway and is involved in maintenance of adipose tissue homeostasis and systemic metabolism.

Protein networks have been widely explored but most binding affinities remain unknown, limiting the quantitative interpretation of interactomes. Here the authors measure affinities of 65,000 interactions involving human PDZ domains and target sequence motifs relevant for viral infection and cancer.

Ubiquitin is not only a posttranslational modifier but itself is subject to modifications, such as acetylation. Characterization of distinct acetylated ubiquitin variants reveals that each acetylation site has a particular impact on ubiquitin structure and its protein-protein interaction properties.

Trypanosomes can sense signal molecules and coordinate their movement in response to such signals, a phenomenon termed social motility (SoMo). Here, Bachmaier et al show that cyclic AMP response protein 3 (CARP3) localization to the flagellar tip and its interaction with a number of different adenylate cyclases is essential for migration to tsetse fly salivary glands and for SoMo, therewith linking SoMo and cAMP signaling to trypanosome transmission.

Protein kinase-mediated phosphorylation plays a critical role in many biological processes. Here the authors develop a trans-omics-based algorithm called Central Kinase Inference to integrate quantitative transcriptomic and phosphoproteomic data, finding that PIM1 promotes hepatic conversion by suppressing reprogramming-induced ferroptosis and cell cycle arrest.

Autophagy is known to impact CD4+ T cell proliferation but the identity of autophagosomal components remain unclear. Here the authors leverage a transgenic mouse model to assess the autophagosomal compartment and identify interleukin-7 receptor-α as a key cargo in proliferating CD4+ T cells.

Methods to identify protein interaction networks often suffer from poor spatiotemporal resolution. Here the authors present a light-activated proximity labeling method where the protein of interest is fused to the photosensitizer protein miniSOG, allowing temporally resolved labeling of interactors.

Determination of interactions between native proteins in cells is important for understanding function. Here the authors report MolBoolean as a method to detect interactions between endogenous proteins in subcellular compartments, using antibody-DNA conjugates for identification and signal amplification.

Hybrid incompatibility can be an important element of reproductive isolation and speciation. Using chromosome replacement lines of yeast, the authors show that perturbed proteostasis caused by destabilized hybrid protein complexes may represent a general mechanism of hybrid incompatibility.

Co-fractionation/mass spectrometry (CF/MS) allows mapping protein interactomes but efficiency and quantitative accuracy are limited. Here, the authors develop a reproducible multiplexed CF/MS method and apply it to characterize interactome rewiring in breast cancer cells.

Cross-linking mass spectrometry is widely used to elucidate protein structures and interactions. Here, the authors generate an extensive peptide library to benchmark the most common cross-link search engines with frequently used cross-linking reagents in low and high complex sample systems.

Autophagy can selectively target cargo for degradation. Here the authors map the proximal interactome of ATG8-paralogs LC3B and LC3C uncovering an LC3C-Endocytic-Associated-Pathway that selectively recruits internalized plasma membrane cargo, Met and transferrin receptors, to nascent autophagosomes.

Pan-cancer proteomics analysis enables the analysis of protein expression across multiple cancer types. Here, the authors compare proteomics from 14 cancer types and show 11 distinct subtypes across multiple cancer types. Proteome data could link higher pathway activity levels with somatic alteration of specific genes in the pathway.

Autism impacts synapses. This study reports that autism-linked mutations of CTTNBP2 regulate phase separation to control synaptic enrichment of that protein. A zinc-induced liquid-to-gel transition improves synaptic retention of CTTNBP2 and SHANK3.

Transcription factors (TFs) interact with several other proteins in the process of transcriptional regulation. Here the authors identify 6703 and 1536 protein–protein interactions for 109 different human TFs through BioID and AP-MS analyses, respectively.

The spatial organization of cell surface receptors is critical for cell signaling and drug action. Here, the authors develop an optoproteomic method for mapping surface protein interactions, revealing cellular responses to antibodies, drugs and viral particles as well as immunosynapse signaling events.

Many interactions between viral and host proteins are mediated by short peptide motifs. Here, using a phage-based viral peptide library, the authors identify 269 peptide-based interactions for 18 coronaviruses, including an interaction between SARS-CoV-2 N and G3BP1/2 that affects stress granules.

Several proteomic approaches allow the analysis of covalent protein SUMOylation, but it remains challenging to systematically study the consequences of a substrate being modified. Here, the authors combine proximity biotinylation and protein-fragment complementation to identify SUMO-dependent protein interactors.

Proximity biotinylation is a powerful tool to profile interactomes, but it requires genetic engineering of the target protein. Here, the authors develop a proximity biotinylation enzyme that can be directed to the target using antibodies, enabling interactome profiling of endogenous proteins or PTMs.

Mitochondria in skeletal muscle have distinct localization and properties through unclear mechanisms. Here, the authors use complexome profiling and immunoprecipitations to identify PERM1 as a MICOS-MIB complex interactor that also binds ankyrin B, suggesting PERM1 directs the mitochondria to the membrane.

Nicotinic acid adenine dinucleotide phosphate (NAADP) potent Ca²⁺ mobilizing second messenger which uniquely triggers Ca²⁺ release from acidic endolysosomal organelles. Here the authors identify Lsm12 as an NAADP receptor essential for NAADP-evoked Ca²⁺ release from lysosomes via NAADP binding on its Lsm domain.

Many proteins exist in various proteoforms but detecting these variants by bottom-up proteomics remains difficult. Here, the authors present a computational approach based on peptide correlation analysis to identify and characterize proteoforms from bottom-up proteomics data.

Cross-linking mass spectrometry (MS) can identify protein-protein interaction (PPI) networks but assessing the reliability of these data remains challenging. To address this issue, the authors develop and validate a method to determine the false-discovery rate of PPIs identified by cross-linking MS.

While the role of specific posttranslational modifications (PTMs) is increasingly well understood for core histones, this is not the case for linker histone H1. Here the authors show that site-specific ubiquitylation of H1 results in distinct interactomes, regulates phase separation, and modulates assembly of chromatosomes.

Predicting chromatographic retention times (RTs) has proven beneficial in proteomics but has not yet been achieved for crosslinked peptides. Here, the authors develop an RT prediction tool for crosslinked peptides and leverage predicted RTs to increase identifications in crosslinking mass spectrometry studies.

Here the authors develop mosquito cell lines expressing Zika virus (ZIKV) capsid and perform proteomics experiments retrieving 157 protein interactors, of which they show 8 to act as pro-viral factors, showing the transitional endoplasmic reticulum 94 (TER94) and its human ortholog VCP target ZIKV capsid to proteasomal degradation to facilitate infection.

Genetic variation can impact protein complexes and interaction networks, but reconciling genetic and proteomic information remains challenging. To address this need, the authors develop Genoppi —a computational tool for integrating genetics and cell-type-specific proteomics data.

The transcription-coupled repair pathway removes transcription-blocking DNA lesions, but how transcription is restored following DNA repair is not clear. Here the authors reveal that the PAF1 complex, while dispensable for the repair process, restores transcription after DNA damage.

Synaptic vesicles store neurotransmitters and fuse with the pre-synaptic membrane when an action potential arrives at the nerve terminal. Here authors apply cross-linking mass spectrometry to study interactions of synaptic vesicle proteins and describe a protein network of vesicle sub-populations and functional assemblies.

APEX-based proximity labeling allows capturing protein interaction dynamics but its high labeling background limits its utility for cytosolic proteins. Here, the authors develop more selective proximity labeling probes, enabling the APEX-based characterization of time-resolved cytosolic protein interactomes.

The IMEx consortium provides one of the largest resources of curated, experimentally verified molecular interaction data. Here, the authors review how IMEx evolved into a fundamental resource for life scientists and describe how IMEx data can support biomedical research.

Cell surface proteins contribute to neuronal development and activity-dependent synaptic plasticity. Here, the authors perform a time-resolved surfaceome analysis of developing primary neurons and in response to homeostatic synaptic scaling and chemical long-term potentiation (cLTP), revealing surface proteome remodeling largely independent of global proteostasis.

Herpesviruses code for conserved protein kinases (CHPKs) that exert several regulatory functions by interacting with cellular factors. Here, the authors use affinity purification mass spectrometry (AP–MS) to identify differential interaction partners of CHPKs from seven different human herpesviruses, finding Cyclin A and associated factors as a specific signature of β-herpesvirus kinases.

Diseases can be associated with various mutations of the same gene, but the molecular consequences of specific mutations remain incompletely understood. Here, the authors present an integrated proteomic workflow to determine the molecular response of cells to different cancer-associated mutations of the kinase Dyrk2.

Patients with spinocerebellar ataxia type 1 express ataxin-1 with an extended polyglutamine (polyQ) tract that forms distinctive nuclear bodies. Here, the authors characterize the cellular pathways affected by polyQ-ataxin-1, showing that it disrupts multiple nuclear transport processes.

Formaldehyde (FA) is a popular cross-linking reagent, but applying it for cross-linking mass spectrometry (XLMS) has been largely unsuccessful. Here, the authors show that cross-links in structured proteins are the product of two FA molecules and identify hundreds of FA cross-links by XLMS in vitro and in situ.

Titin determines the elasticity of the sarcomere and integrates into both the Z-disc and the M-band. Here, the authors generate a BioID mouse to study the titin interactome at the Z-disc region in neonatal and adult heart and skeletal muscle.

Protein-protein interactions are fundamental to the regulation of protein activity and cellular phyisology. Here the authors present Split Intein-Mediated Protein Ligation, which uses bait and prey proteins fused to intein fragments to generate single intact proteins upon interaction.

The mechanisms of action of proteasome inhibitors (PI) in multiple myeloma (MM) treatment are not fully elucidated. Here, the authors use unbiased phosphoproteomics in PI-treated MM and show increased phosphorylation of splicing-associated proteins, ultimately revealing splicing interference as a mode of PI action as well as demonstrating the spliceosome as a specific therapeutic vulnerability in this disease.

The MET receptor is frequently activated in cancer. Here, the authors show that in head and neck and lung squamous carcinoma, a polymorphic MET variant enhances binding to HER2, resulting in activation of HER2 signalling and progression of the cancers.