Protein Succinylation and Malonylation as Potential Biomarkers in Schizophrenia.

Two protein post-translational modifications, lysine succinylation and malonylation, are implicated in protein regulation, glycolysis, and energy metabolism. The precursors of these modifications, succinyl-CoA and malonyl-CoA, are key players in central metabolic processes. Both modification profiles have been proven to be responsive to metabolic stimuli, such as hypoxia.

Cannabinoids modulate proliferation, differentiation, and migration signaling pathways in oligodendrocytes.

Cannabinoid signaling, mainly via CB1 and CB2 receptors, plays an essential role in oligodendrocyte health and functions. However, the specific molecular signals associated with the activation or blockade of CB1 and CB2 receptors in this glial cell have yet to be elucidated. Mass spectrometry-based shotgun proteomics and in silico biology tools were used to determine which signaling pathways and molecular mechanisms are triggered in a human oligodendrocytic cell line (MO3.

A glimpse on the architecture of hnRNP C1/C2 interaction network in cultured oligodendrocytes.

hnRNP represent a large family of RNA-binding proteins related to regulation of transcriptional and translational processes. More specifically, hnRNPs play pivotal roles in the myelination of the central nervous system. The regulation of these proteins are associated with neurodegenerative and psychiatric disorders, including schizophrenia.

Deciphering the architecture and interactome of hnRNP proteins and enigmRBPs.

RNA-binding proteins (RBPs) have conserved domains and consensus sequences that interact with RNAs and other proteins forming ribonucleoprotein (RNP) complexes. RNPs are involved in the regulation of several cellular processes, including transcription, pre-mRNA splicing, mRNA transport, localization, degradation and storage, and ultimately control of translation. Heterogeneous nuclear ribonucleoproteins (hnRNPs) comprise a family of RBPs that mediate transcription control and nuclear processing of transcripts.

Evidence of macrophage modulation in the mouse pubic symphysis remodeling during the end of first pregnancy and postpartum.

In mouse pregnancy, pubic symphysis (PS) remodels into an elastic interpubic ligament (IpL) in a temporally regulated process to provide safe delivery. It restores at postpartum to assure reproductive tract homeostasis. Recently, macrophage localization in the IpL and dynamic changes in the expression of inflammatory mediators observed from the end of pregnancy (D18, D19) to early days postpartum (1dpp, 3dpp) highlighted the necessity of the identification of the key molecules involved in innate immune processes in PS remodeling.

Digging deeper in the proteome of different regions from schizophrenia brains.

Schizophrenia is a psychiatric disorder that affects 21 million people worldwide. Despite several studies having been shown that some brain regions may play a critical role in the pathophysiology of schizophrenia, the molecular basis to explain this diversity is still lacking. The cerebellum (CER), caudate nucleus (CAU), and posterior cingulate cortex (PCC) are areas associated with negative and cognitive symptoms in schizophrenia.

Unveiling the interaction between the molecular motor Myosin Vc and the small GTPase Rab3A.

Vertebrates usually have three class V myosin paralogues (MyoV) to control membrane trafficking in the actin-rich cell cortex, but their functional overlapping or differentiation through cargoes selectivity is yet only partially understood. In this work, we reveal that the globular tail domain of MyoVc binds to the active form of small GTPase Rab3A with nanomolar affinity, a feature shared with MyoVa but not with MyoVb. Using molecular docking analyses guided by chemical cross-linking restraints, we propose a model to explain how Rab3A selectively recognizes MyoVa and MyoVc via a distinct binding site from that used by Rab11A.

A Complete Proteomic Workflow to Study Brain-Related Disorders via Postmortem Tissue.

Here we describe a mass spectrometry-based proteomics workflow to discovery proteins differentially regulated in brains collected postmortem from mental, neurological, or substance abuse disorders (MNS) patients. One way to maximize protein detection is to carry out enrichment of cellular compartments such as the nucleus, mitochondria and cytosol. Subcellular fractionation improves proteome coverage and may shed light on the role of these organelles in the pathophysiology of MNS.

A Guide to Mass Spectrometry-Based Quantitative Proteomics.

Proteomics has become an attractive science in the postgenomic era, given its capacity to identify up to thousands of molecules in a single, complex sample and quantify them in an absolute and/or relative manner. The use of these techniques enables understanding of cellular and molecular mechanisms of diseases and other biological conditions, as well as identification and screening of protein biomarkers. Here we provide a straightforward, up-to-date compilation and comparison of the main quantitation techniques used in comparative proteomics such as in vitro and in vivo stable isotope labeling and label-free techniques.

Combined Role of the Asymmetric Counteranion-Directed Catalysis (ACDC) and Ionic Liquid Effect for the Enantioselective Biginelli Multicomponent Reaction.

This work describes new chiral task-specific ionic liquids bearing chiral anions as the catalysts for the enantioselective multicomponent Biginelli reaction. For the first time, the combined role of asymmetric counteranion-directed catalysis (ACDC) and ionic liquid effect (ILE) for the chiral induction in the Biginelli multicomponent reaction is demonstrated. The chiral induction arises from a supramolecular aggregate where the anion and the cation of the catalyst are alongside with a key cationic intermediate of the reaction.

XPlex: An Effective, Multiplex Cross-Linking Chemistry for Acidic Residues.

Cross-linking/Mass spectrometry (XLMS) is a consolidated technique for structural characterization of proteins and protein complexes. Despite its success, the cross-linking chemistry currently used is mostly based on N-hydroxysuccinimide (NHS) esters, which react primarily with lysine residues. One way to expand the current applicability of XLMS into several new areas is to increase the number of cross-links obtainable for a target protein.

Heteropolyacid-Containing Ionic Liquid-Catalyzed Multicomponent Synthesis of Bridgehead Nitrogen Heterocycles: Mechanisms and Mitochondrial Staining.

The current manuscript describes the use of a heteropolyacid-containing task-specific ionic liquid, supported in imidazolium-based ionic liquids, as the catalyst for an efficient multicomponent synthesis of hexahydroimidazo[1,2-α]pyridine derivatives. The reactions conditions were fully optimized, and the bridgehead nitrogen heterocycle derivatives could be obtained in just 1 h exclusively as a single isomer ( trans). Single crystal X-ray analysis confirmed the trans derivative as the only isomer.

Characterization of homodimer interfaces with cross-linking mass spectrometry and isotopically labeled proteins.

Cross-linking coupled with mass spectrometry (XL-MS) has emerged as a powerful strategy for the identification of protein-protein interactions, characterization of interaction regions, and obtainment of structural information on proteins and protein complexes. In XL-MS, proteins or complexes are covalently stabilized with cross-linkers and digested, followed by identification of the cross-linked peptides by tandem mass spectrometry (MS/MS). This provides spatial constraints that enable modeling of protein (complex) structures and regions of interaction.

LC-MS for Qualitative and Quantitative Proteomic Studies of Psychiatric Disorders.

This chapter describes the advantages and disadvantages of label-free liquid chromatography mass spectrometry in data-independent analysis mode (LC-MS) in the identification of disease biomarkers in studies of psychiatric disorders. Along with the description of the technology, we discuss some of the most significant findings from various studies of post-mortem brain and neuroendocrine tissues from psychiatric disorder patients compared with controls. In addition, we describe some of the needs and challenges of performing these analyses in body fluids and peripheral tissues from living patients in order to increase translation of the findings into the clinical environment.

The SEB-1 Transcription Factor Binds to the STRE Motif in Neurospora crassa and Regulates a Variety of Cellular Processes Including the Stress Response and Reserve Carbohydrate Metabolism.

When exposed to stress conditions, all cells induce mechanisms resulting in an attempt to adapt to stress that involve proteins which, once activated, trigger cell responses by modulating specific signaling pathways. In this work, using a combination of pulldown assays and mass spectrometry analyses, we identified the Neurospora crassa SEB-1 transcription factor that binds to the Stress Response Element (STRE) under heat stress. Orthologs of SEB-1 have been functionally characterized in a few filamentous fungi as being involved in stress responses; however, the molecular mechanisms mediated by this transcription factor may not be conserved.

[des-Arg(1)]-Proctolin: A novel NEP-like enzyme inhibitor identified in Tityus serrulatus venom.

The scorpion Tityus serrulatus venom comprises a complex mixture of molecules that paralyzes and kills preys, especially insects. However, venom components also interact with molecules in humans, causing clinic envenomation. This cross-interaction may result from homologous molecular targets in mammalians and insects, such as (NEP)-like enzymes.

Parameters of the reproductive tract, spermatogenesis, daily sperm production and major seminal plasma proteins of tropically adapted morada nova rams.

This study describes the reproductive parameters of Morada Nova rams, a breed of hair sheep from Brazil and with unique adaption to tropical environments. At 42 weeks of age, 15 rams were subjected to semen collection and, 1 week later, animals were slaughtered for collection of testes, epididymis and accessory sex glands. We conducted 2-D electrophoresis of seminal plasma proteins and major spots of stained gels were identified by LC-MS/MS.

Insights into scorpion venom peptides: alternative processing of β-KTx propeptide from Tityus serrulatus venom results in a new naturally occurring thimet oligopeptidase inhibitor.

Most functions attributed to Tityus serrulatus venom (TsV) are related to active molecules on ion-channels; however, here we describe a new pentapeptide that was discovered through enzymatic assay selection using EP24.15. The primary structure analysis revealed the sequence KEXXG (X means Ile or Leu), similar to the sequence present in the β-KTX propeptide described from the venom of Tityus spp.

Analysis of secondary structure in proteins by chemical cross-linking coupled to MS.

Chemical cross-linking is an attractive technique for the study of the structure of protein complexes due to its low sample consumption and short analysis time. Furthermore, distance constraints obtained from the identification of cross-linked peptides by MS can be used to construct and validate protein models. If a sufficient number of distance constraints are obtained, then determining the secondary structure of a protein can allow inference of the protein's fold.

Proteomic analysis of the reproductive tract fluids from tropically-adapted Santa Ines rams.

The present study is focused on the proteome of reproductive tract fluids from tropically-adapted Santa Ines rams. Seminal plasma, cauda epididymal (CEF) and vesicular gland fluid (VGF) proteins were analyzed by 2-D electrophoresis and mass spectrometry. Seminal plasma maps contained 302 ± 16 spots, within the 4-7 pH range.

Improving metallomics information related to transgenic and non-transgenic soybean seeds using 2D-HPLC-ICP-MS and ESI-MS/MS.

This work reports the use of 2D-HPLC-ICP-MS to enlarge metallomics information when considering soybean seeds. Separations using size exclusion chromatography (SEC) allowed the identification of three metal fractions: the first corresponding to molecular weights from 38.1 to 181.

FERM domain interaction with myosin negatively regulates FAK in cardiomyocyte hypertrophy.

Focal adhesion kinase (FAK) regulates cellular processes that affect several aspects of development and disease. The FAK N-terminal FERM (4.1 protein-ezrin-radixin-moesin homology) domain, a compact clover-leaf structure, binds partner proteins and mediates intramolecular regulatory interactions.