Search Results (77)

While deep learning has advanced object detection through hierarchical feature learning and end-to-end optimization, conventional random sampling paradigms exhibit critical limitations in addressing hyperspectral ambiguity and low-distinguishability challenges in ground-based cloud detection. To overcome these limitations, we propose CurriCloud, a loss-adaptive curriculum framework featuring three key innovations: (1) real-time sample evaluation via Unified Batch Loss (UBL) for difficulty measurement, (2) stabilized training monitoring through a sliding window queue mechanism, and (3) progressive sample selection aligned with model capability using meteorology-guided phase-wise threshold scheduling. Extensive experiments on the ALPACLOUD benchmark demonstrate CurriCloud’s effectiveness across diverse architectures (YOLOv10s, SSD, and RT-DETR-R50), achieving consistent improvements of +3.1% to +11.4% mAP50 over both random sampling baselines and existing curriculum learning methods. Full article

Advancing age in men significantly contributes to declining sperm fertility. Information on age-related proteomic changes in spermatozoa is limited. This study involved normal fertile Arab men in three age groups: young adult (21–30 years; n = 6), late adult (31–40 years; n = 7), and advanced age (40–51 years; n = 5). Gradient-purified spermatozoa were analyzed using LC-MS/MS and proteomic data were processed using Progenesis QI (QIfp) v3.0 and UniProt/SwissProt. Significantly enriched annotations and clustering of proteins in the proteomic datasets were identified (2-fold change; p < 0.05). A total of 588 proteins were identified, with 93% shared across the three groups. Unique proteins were MYLK4 for the young adult group, PRSS57 for the late adult group, and HMGB4, KRT4, LPGAT1, OXCT2, and MGRN1 for the advanced age group. Furthermore, 261 (44%) proteins were differentially expressed (p < 0.05) across the three groups. Functional enrichment analysis suggested an aging-related significant increase in pathways associated with neurodegenerative diseases and protein folding, alongside decreases in glycolysis/gluconeogenesis, flagellated sperm motility, acetylation, phosphoprotein modifications, oxidation processes, and Ubl conjugation. Cluster analysis highlighted significantly upregulated proteins in young adults (e.g., H2BC1, LAP3, SQLE, LTF, PDIA4, DYNLT2) and late adults (e.g., ATP5F1B, ODF2, TUBA3C, ENO1, SPO11, TEX45, TEKT3), whereas most proteins in the advanced age group exhibited downregulation (e.g., SPESP1, RAB10, SEPTIN4, RAB15, PTPN7, USP5, ANXA1, PRDX1). In conclusion, this study revealed aging-associated proteomic changes in spermatozoa that impact critical processes, including spermatogenesis, motility, metabolism, and fertilization, potentially contributing to fertility decline. These changes provide a molecular framework for developing therapies to preserve sperm proteostasis and enhance fertility in older men. Full article

Background: Colonic diverticulosis is a common condition, particularly in the elderly population. While dietary habits, obesity, smoking, and physical inactivity contribute to its pathogenesis, emerging evidence highlights a genetic predisposition affecting extracellular matrix (ECM) remodeling, inflammation, and connective tissue integrity. The aim of this systematic review was to summarize genetic determinants of colonic diverticulosis. Methods: The PubMed^® database was searched for original studies in humans. The inclusion criteria were named genetic factor and confirmed diverticulosis. Patients with diverticulitis and diverticular diseases were excluded from this review. Results: Out of 137 publications, 10 articles met the inclusion criteria: six large association studies (GWAS) and four cross-sectional studies. The genes regulating ECM turnover, including TIMP1, MMP3, and MMP9, are involved in diverticulosis development. The TIMP1 (rs4898) T allele has been associated with increased susceptibility, potentially due to its role in ECM remodeling. Similarly, MMP3 (rs3025058) and MMP9 (rs3918242) polymorphisms contribute to altered collagen degradation. The COL3A1 (rs3134646) variant coding modified collagen type III may promote diverticular formation. Other genes, such as ARHGAP15 (rs4662344, rs6736741), affect cytoskeletal dynamics. Identified in GWAS studies, gene candidates may be grouped into blood group and immune system-related genes (ABO, HLA-DQA1, HLA-H, OAS1, TNFSF13, FADD), extracellular matrix and connective tissue genes (COL6A1, COLQ, EFEMP1, ELN, HAS2, TIMP2), signaling and cell communication (BMPR1B, WNT4, RHOU, PHGR1, PCSK5), nervous system and neurodevelopment (BDNF, CACNB2, GPR158, SIRT1, SCAPER, TRPS1), metabolism and transporters (SLC25A28, SLC35F3, RBKS, PPP1R14A, PPP1R16B), lipids and cholesterol (LDAH, LYPLAL1, STARD13), transcription and gene regulation (ZBTB4, UBTF, TNRC6B), apoptosis (FADD, PIAS1), and poorly characterized genes (C1TNF7, ENSG00000224849, ENSG00000251283, LINC01082, DISP2, SNX24, THEM4, UBL4B, UNC50, WDR70, SREK1IP1). Conclusions: There are a number of gene variants that probably predispose to colonic diverticulosis. Detailed characterization of the multigene background of diverticulosis will enable appropriate therapeutic or preventive interventions in the future. Full article

Unlike other ubiquitin-like family members, UBL5 is structurally and functionally atypical, and a novel role in various biological processes and diseases has been discovered. UBL5 can stabilize the structure of the spliceosome, can promote post-transcriptional processing, and has been implicated in both DNA damage repair and protein unfolding reactions, as well as cellular mechanisms that are frequently exploited by viruses for their own proliferation during viral infections. In addition, UBL5 can inhibit viral infection by binding to the non-structural protein 3 of rice stripe virus and mediating its degradation. Therefore, UBL5 is an important link between viral infections and immunity, and its study will be beneficial for the prevention and treatment of viral infections in the future. However, a review of the current findings on the role of UBL5 in viral infection has not been undertaken. Therefore, in this review, we summarize the recent progress in understanding the functions of UBL5 and discuss its putative role in viral infections. Full article

Background: FAT10 is a member of the ubiquitin-like modifier family. Similar to ubiquitin, FAT10 has a distinct enzyme cascade consisting of E1-activating, E2-conjugating, and possibly several E3-ligating enzymes, which will covalently link FAT10 to substrate proteins in order to target them directly for proteasomal degradation. FAT10 was reported to be phosphorylated by IKKβ during infection with influenza A virus. Methods: To assess the difference between the FAT10-dependent degradation of phosphorylated FAT10 and the non-phosphorylated FAT10 wild type (FAT10 WT), a mutated FAT10 that mimicked phosphorylation (FAT10 D) was constructed by replacing several serine residues and one threonine residue with aspartic or glutamic acid. The FAT10 degradation or conjugation was compared between the phospho-mimetic FAT10 and the wild-type FAT10 with respect to the dependence of the E3 ligase TRIM25, the UBL-UBA protein NUB1L, and the proteasomal ubiquitin receptor RPN10. Results: The phospho-mimetic FAT10 was more efficiently conjugated to substrate proteins as compared to the wild-type FAT10, particularly if TRIM25 was co-expressed. Additionally, the phospho-mimetic FAT10 was not bound by NUB1L. However, this did not affect FAT10 D or FAT10 WT degradation. No differences were found in the binding affinity of phospho-mimetic FAT10 to RPN10. Conclusions: In brief, the phospho-mimetic FAT10 shows enhanced conjugation efficiency, but phosphorylation does not alter its degradation by the proteasome. This reveals that phosphorylation may fine-tune FAT10’s interactions with specific interaction partners without disrupting its core function of proteasomal degradation. Full article

Background/Objectives: UBL3 (Ubiquitin-like 3) is a protein that plays a crucial role in post-translational modifications, particularly in regulating protein transport within small extracellular vesicles. While previous research has predominantly focused on its interactions with α-synuclein, this study investigates UBL3’s role in Huntington’s disease (HD). HD is characterized by movement disorders and cognitive impairments, with its pathogenesis linked to toxic, polyglutamine (polyQ)-expanded mutant huntingtin fragments (mHTT). However, the mechanisms underlying the interaction between UBL3 and mHTT remain poorly understood. Methods: To elucidate this relationship, we performed hematoxylin and eosin (HE) staining and immunohistochemistry (IHC) on postmortem brain tissue from HD patients. Gaussia princeps-based split-luciferase complementation assay and co-immunoprecipitation were employed to confirm the interaction between UBL3 and mHTT. Additionally, we conducted a HiBiT lytic detection assay to assess the influence of UBL3 on the intracellular sorting of mHTT. Finally, immunocytochemical staining was utilized to validate the colocalization and distribution of these proteins. Results: Our findings revealed UBL3-positive inclusions in the cytoplasm and nuclei of neurons throughout the striatum of HD patients. We discovered that UBL3 colocalizes and interacts with mHTT and modulates its intracellular sorting. Conclusions: These results suggest that UBL3 may play a significant role in the interaction and sorting of mHTT, contributing to the understanding of its potential implications in the pathophysiology of Huntington’s disease. Full article

Mutations in the parkin gene product Parkin give rise to autosomal recessive juvenile parkinsonism. Parkin is an E3 ubiquitin ligase that is a critical participant in the process of mitophagy. Parkin has a complex structure that integrates several allosteric signals to maintain precise control of its catalytic activity. Though its allosterically controlled structural reorganization has been extensively characterized by crystallography, the energetics and mechanisms of allosteric regulation of Parkin are much less well understood. Allostery is fundamentally linked to the energetics of the cooperative (sub)structure of the protein. Herein, we examine the mechanism of allosteric activation by phosphorylated ubiquitin binding to the enzymatic core of Parkin, which lacks the antagonistic Ubl domain. In this way, the allosteric effects of the agonist phosphorylated ubiquitin can be isolated. Using native-state hydrogen exchange monitored by mass spectrometry, we find that the five structural domains of the core of Parkin are energetically distinct. Nevertheless, association of phosphorylated ubiquitin destabilizes structural elements that bind the ubiquitin-like domain antagonist while promoting the dissociation of the catalytic domain and energetically poises the protein for transition to the fully activated structure. Full article

Post-translational protein modifications (PTMs) significantly enhance the functional diversity of proteins and are therefore important for the expansion and the dynamics of the cell’s proteome. In addition to structurally simpler PTMs, substrates also undergo modification through the reversible attachment of small proteins. The best understood PTM of this nature to date is the covalent conjugation of ubiquitin and ubiquitin-like proteins (UBLs) to their substrates. The protein family of small ubiquitin-like modifier (SUMO) is one of these UBLs that has received increasing scientific attention. The pathway of SUMOylation is highly conserved in all eukaryotic cells and is crucial for their survival. It plays an essential role in many biological processes, such as the maintenance of genomic integrity, transcriptional regulation, gene expression, and the regulation of intracellular signal transduction, and thereby influences DNA damage repair, immune responses, cell cycle progression, and apoptosis. Several studies have already shown that in this context protein SUMOylation is involved in the control mechanisms of various cellular receptors. This article unites data from different studies focusing on the investigation of the strictly conserved three-step enzyme cascade of protein SUMOylation and the functional analysis of the involved proteins E1, E2, and E3 and SUMOylation target proteins. Furthermore, this review highlights the role of nuclear receptor SUMOylation and its importance for the cellular functionality and disease development arising from defects in correct protein SUMOylation. Full article

Aberrant aggregation of misfolded alpha-synuclein (α-syn), a major pathological hallmark of related neurodegenerative diseases such as Parkinson’s disease (PD), can translocate between cells. Ubiquitin-like 3 (UBL3) is a membrane-anchored ubiquitin-fold protein and post-translational modifier. UBL3 promotes protein sorting into small extracellular vesicles (sEVs) and thereby mediates intercellular communication. Our recent studies have shown that α-syn interacts with UBL3 and that this interaction is downregulated after silencing microsomal glutathione S-transferase 3 (MGST3). However, how MGST3 regulates the interaction of α-syn and UBL3 remains unclear. In the present study, we further explored this by overexpressing MGST3. In the split Gaussia luciferase complementation assay, we found that the interaction between α-syn and UBL3 was upregulated by MGST3. While Western blot and RT-qPCR analyses showed that silencing or overexpression of MGST3 did not significantly alter the expression of α-syn and UBL3, the immunocytochemical staining analysis indicated that MGST3 increased the co-localization of α-syn and UBL3. We suggested roles for the anti-oxidative stress function of MGST3 and found that the effect of MGST3 overexpression on the interaction between α-syn with UBL3 was significantly rescued under excess oxidative stress and promoted intracellular α-syn to extracellular transport. In conclusion, our results demonstrate that MGST3 upregulates the interaction between α-syn with UBL3 and promotes the interaction to translocate intracellular α-syn to the extracellular. Overall, our findings provide new insights and ideas for promoting the modulation of UBL3 as a therapeutic agent for the treatment of synucleinopathy-associated neurodegenerative diseases. Full article

Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an essential protein involved in the maintenance of repressive epigenetic marks, ensuring epigenetic stability and fidelity. As an epigenetic regulator, UHRF1 comprises several functional domains (UBL, TTD, PHD, SRA, RING) that are collectively responsible for processes like DNA methylation, histone modification, and DNA repair. UHRF1 is a downstream effector of the RB/E2F pathway, which is nearly universally deregulated in cancer. Under physiological conditions, UHRF1 protein levels are cell cycle-dependent and are post-translationally regulated by proteasomal degradation. Conversely, UHRF1 is overexpressed and serves as an oncogenic driver in multiple cancers. This review focuses on the functional domains of UHRF1, highlighting its key interacting proteins and oncogenic roles in solid tumors including retinoblastoma, osteosarcoma, lung cancer, and breast cancer. Additionally, current therapeutic strategies targeting UHRF1 domains or its interactors are explored, providing an insight on potential clinical applications. Full article

E3 ubiquitin ligases (UBLs), as enzymes capable of specifically recognizing target proteins in the process of protein ubiquitination, play crucial roles in regulating responses to abiotic stresses such as drought, salt, and temperature. Abscisic acid (ABA), a plant endogenous hormone, is essential to regulating plant growth, development, disease resistance, and defense against abiotic stresses, and acts through a complex ABA signaling pathway. Hormone signaling transduction relies on protein regulation, and E3 ubiquitin ligases play important parts in regulating the ABA pathway. Therefore, this paper reviews the ubiquitin–proteasome-mediated protein degradation pathway, ABA-related signaling pathways, and the regulation of ABA-signaling-pathway-related genes by E3 ubiquitin ligases, aiming to provide references for further exploration of the relevant research on how plant E3 ubiquitin ligases regulate the ABA pathway. Full article

Background: Diffuse large B-cell lymphoma (DLBCL) is one of the most frequent lymphomas. DLBCL is phenotypically, genetically, and clinically heterogeneous. Aim: We aim to identify new prognostic markers. Methods: We performed anomaly detection analysis, other artificial intelligence techniques, and conventional statistics using gene expression data of 414 patients from the Lymphoma/Leukemia Molecular Profiling Project (GSE10846), and immunohistochemistry in 10 reactive tonsils and 30 DLBCL cases. Results: First, an unsupervised anomaly detection analysis pinpointed outliers (anomalies) in the series, and 12 genes were identified: DPM2, TRAPPC1, HYAL2, TRIM35, NUDT18, TMEM219, CHCHD10, IGFBP7, LAMTOR2, ZNF688, UBL7, and RELB, which belonged to the apoptosis, MAPK, MTOR, and NF-kB pathways. Second, these 12 genes were used to predict overall survival using machine learning, artificial neural networks, and conventional statistics. In a multivariate Cox regression analysis, high expressions of HYAL2 and UBL7 were correlated with poor overall survival, whereas TRAPPC1, IGFBP7, and RELB were correlated with good overall survival (p < 0.01). As a single marker and only in RCHOP-like treated cases, the prognostic value of RELB was confirmed using GSEA analysis and Kaplan–Meier with log-rank test and validated in the TCGA and GSE57611 datasets. Anomaly detection analysis was successfully tested in the GSE31312 and GSE117556 datasets. Using immunohistochemistry, RELB was positive in B-lymphocytes and macrophage/dendritic-like cells, and correlation with HLA DP-DR, SIRPA, CD85A (LILRB3), PD-L1, MARCO, and TOX was explored. Conclusions: Anomaly detection and other bioinformatic techniques successfully predicted the prognosis of DLBCL, and high RELB was associated with a favorable prognosis. Full article

This study presents findings regarding the kinetics of ferrous iron oxidation in solution mediated by Acidithiobacillus ferrooxidans bacteria within a continuous-flow bioreactor employing diverse types of immobilizers. The objective is to augment the rate of ferrous iron oxidation in solutions utilizing an immobilizer for Acidithiobacillus ferrooxidans strains. Immobilization represents a promising avenue for enhancing the efficiency of Fe²⁺ oxidation via acidophilic ferrooxidizing bacteria, leading to a several-fold increase in oxidation rate. A comparative analysis was conducted to evaluate the efficacy of different types of immobilizer in facilitating iron oxidation within a continuous-flow bioreactor, including the application of wood chips coated with Fe(OH)₃. The results indicate that wood chips coated with iron hydroxide serve as effective type of immobilizer, facilitating the robust attachment of Acidithiobacillus ferrooxidans via electrostatic interactions between negatively charged bacteria and positively charged surfaces. Experimental investigations were conducted using novel immobilization matrices in pilot-scale tests simulating the underground borehole leaching (UBL) of uranium. The bioactivation of leaching solutions enhances the efficiency and environmental compatibility of UBL compared to conventional chemical oxidation methods. The relationships between redox potential and ferric iron content in bioactivated solutions during the UBL of uranium were delineated. The significance of this study lies in its elucidating the pivotal role of Fe²⁺ oxidation in uranium extraction processes, particularly in the context of UBL. By employing bioactivation mediated by Acidithiobacillus ferrooxidans, the study demonstrates not only enhanced uranium extraction efficiency, but also markedly improved environmental sustainability compared to traditional chemical oxidation methods. The findings reveal crucial correlations between redox potential and ferric iron concentration in bioactivated solutions. Full article

The ubiquitin-proteasome system (UPS) is a pivotal cellular mechanism responsible for the selective degradation of proteins, playing an essential role in proteostasis, protein quality control, and regulating various cellular processes, with ubiquitin marking proteins for degradation through a complex, multi-stage process. The shuttle proteins family is a very unique group of proteins that plays an important role in the ubiquitin-proteasome system. Ddi1, Dsk2, and Rad23 are shuttle factors that bind ubiquitinated substrates and deliver them to the 26S proteasome. Besides mediating the delivery of ubiquitinated proteins, they are also involved in many other biological processes. Ddi1, the least-studied shuttle protein, exhibits unique physicochemical properties that allow it to play non-canonical functions in the cells. It regulates cell cycle progression and response to proteasome inhibition and defines MAT type of yeast cells. The Ddi1 contains UBL and UBA domains, which are crucial for binding to proteasome receptors and ubiquitin respectively, but also an additional domain called RVP. Additionally, much evidence has been provided to question whether Ddi1 is a classical shuttle protein. For many years, the true nature of this protein remained unclear. Here, we highlight the recent discoveries, which shed new light on the structure and biological functions of the Ddi1 protein. Full article

The Interferon Stimulated Gene 15 (ISG15), a unique Ubiquitin-like (Ubl) modifier exclusive to vertebrates, plays a crucial role in the immune system. Primarily induced by interferon (IFN) type I, ISG15 functions through diverse mechanisms: (i) covalent protein modification (ISGylation); (ii) non-covalent intracellular action; and (iii) exerting extracellular cytokine activity. These various roles highlight its versatility in influencing numerous cellular pathways, encompassing DNA damage response, autophagy, antiviral response, and cancer-related processes, among others. The well-established antiviral effects of ISGylation contrast with its intriguing dual role in cancer, exhibiting both suppressive and promoting effects depending on the tumour type. The multifaceted functions of ISG15 extend beyond intracellular processes to extracellular cytokine signalling, influencing immune response, chemotaxis, and anti-tumour effects. Moreover, ISG15 emerges as a promising adjuvant in vaccine development, enhancing immune responses against viral antigens and demonstrating efficacy in cancer models. As a therapeutic target in cancer treatment, ISG15 exhibits a double-edged nature, promoting or suppressing oncogenesis depending on the tumour context. This review aims to contribute to future studies exploring the role of ISG15 in immune modulation and cancer therapy, potentially paving the way for the development of novel therapeutic interventions, vaccine development, and precision medicine. Full article