Capacitation is an essential post-testicular maturation event endowing spermatozoa with fertilizing capacity within the female reproductive tract, significant for fertility, reproductive health, and contraception. By using a human-relevant large animal model, the domestic boar, this study focuses on furthering our understanding of the involvement of the ubiquitin-proteasome system (UPS) in sperm capacitation. The UPS is a universal, evolutionarily conserved, cellular proteome-wide degradation and recycling machinery, that has been shown to play a significant role in reproduction during the past two decades. Herein, we have used a bottom-up proteomic approach to (i) monitor the capacitation-related changes in the sperm protein levels, and (ii) identify the targets of UPS regulation during sperm capacitation. Spermatozoa were capacitated under proteasomal activity-permissive and inhibiting conditions and extracted sperm proteins were subjected to high-resolution mass spectrometry. We report that 401 individual proteins differed at least two-fold in abundance (P < 0.05) after in vitro capacitation (IVC) and 13 proteins were found significantly different (P < 0.05) between capacitated spermatozoa with proteasomal inhibition compared to the vehicle control. These proteins were associated with biological processes including sperm capacitation, sperm motility, metabolism, binding to zona pellucida, and proteasome-mediated catabolism. Changes in RAB2A, CFAP161, and TTR during IVC were phenotyped by immunocytochemistry, image-based flow cytometry, and Western blotting. We conclude that (i) the sperm proteome is subjected to extensive remodeling during sperm capacitation, and (ii) the UPS has a narrow range of distinct protein substrates during capacitation. This knowledge highlights the importance of the UPS in sperm capacitation and offers opportunities to identify novel pharmacological targets to modulate sperm fertilizing ability for the benefit of human reproductive health, assisted reproductive therapy, and contraception, as well as reproductive management in food animal agriculture.

• Klíčová slova
• Pig, Sperm capacitation, Sperm proteomics, Ubiquitin-proteasome system,
• MeSH
• kapacitace spermií * fyziologie   MeSH
• prasata MeSH
• proteasomový endopeptidasový komplex * metabolismus   MeSH
• proteom metabolismus   MeSH
• proteomika * metody   MeSH
• spermie * metabolismus   fyziologie   MeSH
• ubikvitin * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteasomový endopeptidasový komplex * MeSH
• proteom MeSH
• ubikvitin * MeSH

Targeted protein degradation or TPD, is rapidly emerging as a treatment that utilizes small molecules to degrade proteins that cause diseases. TPD allows for the selective removal of disease-causing proteins, including proteasome-mediated degradation, lysosome-mediated degradation, and autophagy-mediated degradation. This approach has shown great promise in preclinical studies and is now being translated to treat numerous diseases, including neurodegenerative diseases, infectious diseases, and cancer. This review discusses the latest advances in TPD and its potential as a new chemical modality for immunotherapy, with a special focus on the innovative applications and cutting-edge research of PROTACs (Proteolysis TArgeting Chimeras) and their efficient translation from scientific discovery to technological achievements. Our review also addresses the significant obstacles and potential prospects in this domain, while also offering insights into the future of TPD for immunotherapeutic applications.

• MeSH
• chiméra pro cílenou proteolýzu MeSH
• imunoterapie * metody   MeSH
• lidé MeSH
• nádory terapie   farmakoterapie   imunologie   metabolismus   MeSH
• proteasomový endopeptidasový komplex * metabolismus   MeSH
• proteolýza * účinky léků   MeSH
• ubikvitin * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• chiméra pro cílenou proteolýzu MeSH
• proteasomový endopeptidasový komplex * MeSH
• ubikvitin * MeSH

Dithiocarbamates (DTCs) are simple organic compounds with many applications in industry and medicine. They are potent metal chelators forming complexes with various metal ions, including copper. Recently, bis(diethyldithiocarbamate)-copper complex (CuET) has been identified as a metabolic product of the anti-alcoholic drug Antabuse (disulfiram, DSF), standing behind DSF's reported anticancer activity. Mechanistically, CuET in cells causes aggregation of NPL4 protein, an essential cofactor of the p97 segregase, an integral part of the ubiquitin-proteasome system. The malfunction of p97/NPL4 caused by CuET leads to proteotoxic stress accompanied by heat shock and unfolded protein responses and cancer cell death. However, it is not known whether the NPL4 inhibition is unique for CuET or whether it is shared with other dithiocarbamate-copper complexes. Thus, we tested 20 DTCs-copper complexes in this work for their ability to target and aggregate NPL4 protein. Surprisingly, we have found that certain potency against NPL4 is relatively common for structurally different DTCs-copper complexes, as thirteen compounds scored in the cellular NPL4 aggregation assay. These compounds also shared typical cellular phenotypes reported previously for CuET, including the NPL4/p97 proteins immobilization, accumulation of polyubiquitinated proteins, the unfolded protein, and the heat shock responses. Moreover, the active complexes were also toxic to cancer cells (the most potent in the nanomolar range), and we have found a strong positive correlation between NPL4 aggregation and cytotoxicity, confirming NPL4 as a relevant target. These results show the widespread potency of DTCs-copper complexes to target NPL4 with subsequent induction of lethal proteotoxic stress in cancer cells with implications for drug development.

• Klíčová slova
• Cancer, Copper complex, CuET, Dithiocarbamates, NPL4 protein, Proteotoxic stress,
• MeSH
• disulfiram farmakologie   MeSH
• dithiokarb * farmakologie   MeSH
• měď * farmakologie   MeSH
• nádory * farmakoterapie   MeSH
• proteasomový endopeptidasový komplex MeSH
• proteiny metabolismus   MeSH
• ubikvitin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bis(diethyldithiocarbamate)-copper complex MeSH Prohlížeč
• disulfiram MeSH
• dithiokarb * MeSH
• měď * MeSH
• proteasomový endopeptidasový komplex MeSH
• proteiny MeSH
• ubikvitin MeSH

Two-dimensional mass spectrometry (2D MS) is a multiplexed tandem mass spectrometry method that does not rely on ion isolation to correlate the precursor and fragment ions. On a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS), 2D MS instead uses the modulation of precursor ion radii inside the ICR cell before fragmentation and yields 2D mass spectra that show the fragmentation patterns of all the analytes. In this study, we perform 2D MS for the first time with quadrupolar detection in a dynamically harmonized ICR cell. We discuss the advantages of quadrupolar detection in 2D MS and how we adapted existing data processing techniques for accurate frequency-to-mass conversion. We apply 2D MS with quadrupolar detection to the top-down analysis of covalently labeled ubiquitin with ECD fragmentation, and we develop a workflow for label-free relative quantification of biomolecule isoforms in 2D MS.

• MeSH
• cyklotrony MeSH
• Fourierova analýza MeSH
• proteomika * metody   MeSH
• tandemová hmotnostní spektrometrie * metody   MeSH
• ubikvitin MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ubikvitin MeSH

Endocytosis controls the perception of stimuli by modulating protein abundance at the plasma membrane. In plants, clathrin-mediated endocytosis is the most prominent internalization pathway and relies on two multimeric adaptor complexes, the AP-2 and the TPLATE complex (TPC). Ubiquitination is a well-established modification triggering endocytosis of cargo proteins, but how this modification is recognized to initiate the endocytic event remains elusive. Here we show that TASH3, one of the large subunits of TPC, recognizes ubiquitinated cargo at the plasma membrane via its SH3 domain-containing appendage. TASH3 lacking this evolutionary specific appendage modification allows TPC formation but the plants show severely reduced endocytic densities, which correlates with reduced endocytic flux. Moreover, comparative plasma membrane proteomics identified differential accumulation of multiple ubiquitinated cargo proteins for which we confirm altered trafficking. Our findings position TPC as a key player for ubiquitinated cargo internalization, allowing future identification of target proteins under specific stress conditions.

• MeSH
• buněčná membrána metabolismus   MeSH
• endocytóza * MeSH
• klathrin * genetika   metabolismus   MeSH
• ubikvitin metabolismus   MeSH
• ubikvitinace MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• klathrin * MeSH
• ubikvitin MeSH

HDMX and its homologue HDM2 are two essential proteins for the cell; after genotoxic stress, both are phosphorylated near to their RING domain, specifically at serine 403 and 395, respectively. Once phosphorylated, both can bind the p53 mRNA and enhance its translation; however, both recognize p53 protein and provoke its degradation under normal conditions. HDM2 has been well-recognized as an E3 ubiquitin ligase, whereas it has been reported that even with the high similarity between the RING domains of the two homologs, HDMX does not have the E3 ligase activity. Despite this, HDMX is needed for the proper p53 poly-ubiquitination. Phosphorylation at serine 395 changes the conformation of HDM2, helping to explain the switch in its activity, but no information on HDMX has been published. Here, we study the conformation of HDMX and its phospho-mimetic mutant S403D, investigate its E3 ligase activity and dissect its binding with p53. We show that phospho-mutation does not change the conformation of the protein, but HDMX is indeed an E3 ubiquitin ligase in vitro; however, in vivo, no activity was found. We speculated that HDMX is regulated by induced fit, being able to switch activity accordingly to the specific partner as p53 protein, p53 mRNA or HDM2. Our results aim to contribute to the elucidation of the contribution of the HDMX to p53 regulation.

• Klíčová slova
• HDM2, HDMX, Induced fit, MDM2, MDMX, cancer, p53, ubiquitination,
• MeSH
• jaderné proteiny genetika   MeSH
• messenger RNA metabolismus   MeSH
• nádorový supresorový protein p53 * genetika   metabolismus   MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• protoonkogenní proteiny c-mdm2 * genetika   metabolismus   MeSH
• protoonkogenní proteiny genetika   MeSH
• serin metabolismus   MeSH
• ubikvitin genetika   MeSH
• ubikvitinace MeSH
• ubikvitinligasy genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• jaderné proteiny MeSH
• messenger RNA MeSH
• nádorový supresorový protein p53 * MeSH
• proteiny buněčného cyklu MeSH
• protoonkogenní proteiny c-mdm2 * MeSH
• protoonkogenní proteiny MeSH
• serin MeSH
• ubikvitin MeSH
• ubikvitinligasy MeSH

The family of deubiquitinases (DUBs) comprises ∼100 enzymes that cleave ubiquitin from substrate proteins and thereby regulate key aspects of human physiology. DUBs have recently emerged as disease-relevant and chemically tractable, although currently there are no approved DUB-targeting drugs and most preclinical small molecules are low-potency and/or multitargeted. We paired a novel capillary electrophoresis microchip containing an integrated, "on-chip" C18 bed (SPE-ZipChip) with a TMT version of our recently described PRM-LIVE acquisition scheme on a timsTOF Pro mass spectrometer to facilitate rapid activity-based protein profiling of DUB inhibitors. We demonstrate the ability of the SPE-ZipChip to improve proteome coverage of complex samples as well as the quantitation integrity of CE-PRM-LIVE for TMT labeled samples. These technologies provide a platform to accurately quantify competitive binding of covalent and reversible inhibitors in a multiplexed assay that spans 49 endogenous DUBs in less than 15 min.

• MeSH
• deubikvitinasy metabolismus   MeSH
• elektroforéza kapilární MeSH
• elektroforéza mikročipová * MeSH
• lidé MeSH
• proteom MeSH
• ubikvitin * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• deubikvitinasy MeSH
• proteom MeSH
• ubikvitin * MeSH

BACKGROUND: Ubiquitin ligases (Ub-ligases) are essential intracellular enzymes responsible for the regulation of proteome homeostasis, signaling pathway crosstalk, cell differentiation and stress responses. Individual Ub-ligases exhibit their unique functions based on the nature of their substrates. They create a complex regulatory network with alternative and feedback pathways to maintain cell homeostasis, being thus important players in many physiological and pathological conditions. However, the functional classification of Ub-ligases needs to be revised and extended. METHODS: In the current study, we used a novel semantic biclustering technique for expression profiling of Ub-ligases and ubiquitination-related genes in the murine gastrointestinal tract (GIT). We accommodated a general framework of the algorithm for finding tissue-specific gene expression clusters in GIT. In order to test identified clusters in a biological system, we used a model of epithelial regeneration. For this purpose, a dextran sulfate sodium (DSS) mouse model, following with in situ hybridization, was used to expose genes with possible compensatory features. To determine cell-type specific distribution of Ub-ligases and ubiquitination-related genes, principal component analysis (PCA) and Uniform Manifold Approximation and Projection technique (UMAP) were used to analyze the Tabula Muris scRNA-seq data of murine colon followed by comparison with our clustering results. RESULTS: Our established clustering protocol, that incorporates the semantic biclustering algorithm, demonstrated the potential to reveal interesting expression patterns. In this manner, we statistically defined gene clusters consisting of the same genes involved in distinct regulatory pathways vs distinct genes playing roles in functionally similar signaling pathways. This allowed us to uncover the potentially redundant features of GIT-specific Ub-ligases and ubiquitination-related genes. Testing the statistically obtained results on the mouse model showed that genes clustered to the same ontology group simultaneously alter their expression pattern after induced epithelial damage, illustrating their complementary role during tissue regeneration. CONCLUSIONS: An optimized semantic clustering protocol demonstrates the potential to reveal a readable and unique pattern in the expression profiling of GIT-specific Ub-ligases, exposing ontologically relevant gene clusters with potentially redundant features. This extends our knowledge of ontological relationships among Ub-ligases and ubiquitination-related genes, providing an alternative and more functional gene classification. In a similar way, semantic cluster analysis could be used for studding of other enzyme families, tissues and systems.

• Klíčová slova
• Cluster analysis, GIT, Gene redundancy, Regeneration, Semantic biclustering, Ub-ligase,
• MeSH
• gastrointestinální trakt metabolismus   MeSH
• lidé MeSH
• myši MeSH
• sémantika * MeSH
• shluková analýza MeSH
• ubikvitin genetika   metabolismus   MeSH
• ubikvitinligasy * genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ubikvitin MeSH
• ubikvitinligasy * MeSH

BACKGROUND: Many regulatory circuits in plants contain steps of targeted proteolysis, with the ubiquitin proteasome system (UPS) as the mediator of these proteolytic events. In order to decrease ubiquitin-dependent proteolysis, we inducibly expressed a ubiquitin variant with Arg at position 48 instead of Lys (ubK48R). This variant acts as an inhibitor of proteolysis via the UPS, and allowed us to uncover processes that are particularly sensitive to UPS perturbation. RESULTS: Expression of ubK48R during germination leads to seedling death. We analyzed the seedling transcriptome, proteome and metabolome 24 h post ubK48R induction and confirmed defects in chloroplast development. We found that mutations in single genes can suppress seedling lethality, indicating that a single process in seedlings is critically sensitive to decreased performance of the UPS. Suppressor mutations in phototropin 2 (PHOT2) suggest that a contribution of PHOT2 to chloroplast protection is compromised by proteolysis inhibition. CONCLUSIONS: Overall, the results reveal protein turnover as an integral part of a signal transduction chain that protects chloroplasts during development.

• Klíčová slova
• Chlorophagy, Chloroplast development, Light signal transduction, Light stress, Photomorphogenesis, Phototropin, Ubiquitin K48 chains,
• MeSH
• chloroplasty genetika   metabolismus   MeSH
• metabolom MeSH
• proteasomový endopeptidasový komplex * genetika   metabolismus   MeSH
• proteolýza MeSH
• semenáček genetika   metabolismus   MeSH
• transkriptom MeSH
• ubikvitin * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteasomový endopeptidasový komplex * MeSH
• ubikvitin * MeSH

Nuclear deubiquitinase BAP1 (BRCA1-associated protein 1) is a core component of multiprotein complexes that promote transcription by reversing the ubiquitination of histone 2A (H2A). BAP1 is a tumor suppressor whose germline loss-of-function variants predispose to cancer. To our knowledge, there are very rare examples of different germline variants in the same gene causing either a neurodevelopmental disorder (NDD) or a tumor predisposition syndrome. Here, we report a series of 11 de novo germline heterozygous missense BAP1 variants associated with a rare syndromic NDD. Functional analysis showed that most of the variants cannot rescue the consequences of BAP1 inactivation, suggesting a loss-of-function mechanism. In T cells isolated from two affected children, H2A deubiquitination was impaired. In matching peripheral blood mononuclear cells, histone H3 K27 acetylation ChIP-seq indicated that these BAP1 variants induced genome-wide chromatin state alterations, with enrichment for regulatory regions surrounding genes of the ubiquitin-proteasome system (UPS). Altogether, these results define a clinical syndrome caused by rare germline missense BAP1 variants that alter chromatin remodeling through abnormal histone ubiquitination and lead to transcriptional dysregulation of developmental genes.

• Klíčová slova
• BAP1, BRCA1, UPS, cancer, chromatin remodeling, deubiquitination, histone 2A, intellectual disability, neurodevelopment, tumor, ubiquitin, ubiquitin-proteasome system,
• MeSH
• chromatin chemie   imunologie   MeSH
• dítě MeSH
• faktor C1 hostitelské buňky genetika   imunologie   MeSH
• heterozygot MeSH
• histony genetika   imunologie   MeSH
• kojenec MeSH
• lidé MeSH
• missense mutace * MeSH
• mladiství MeSH
• mutace ztráty funkce * MeSH
• nádorové supresorové proteiny nedostatek   genetika   imunologie   MeSH
• neurovývojové poruchy genetika   imunologie   patologie   MeSH
• předškolní dítě MeSH
• proteasomový endopeptidasový komplex genetika   imunologie   MeSH
• protein BRCA1 genetika   imunologie   MeSH
• regulace genové exprese MeSH
• restrukturace chromatinu genetika   imunologie   MeSH
• rodina MeSH
• T-lymfocyty imunologie   patologie   MeSH
• thiolesterasa ubikvitinu nedostatek   genetika   imunologie   MeSH
• ubikvitin genetika   imunologie   MeSH
• ubikvitinace MeSH
• ubikvitinligasy genetika   imunologie   MeSH
• zárodečné mutace * MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• BAP1 protein, human MeSH Prohlížeč
• BARD1 protein, human MeSH Prohlížeč
• BRCA1 protein, human MeSH Prohlížeč
• chromatin MeSH
• faktor C1 hostitelské buňky MeSH
• HCFC1 protein, human MeSH Prohlížeč
• histony MeSH
• nádorové supresorové proteiny MeSH
• proteasomový endopeptidasový komplex MeSH
• protein BRCA1 MeSH
• thiolesterasa ubikvitinu MeSH
• ubikvitin MeSH
• ubikvitinligasy MeSH