Search Results (107)

The gut, brain, fat body, and various glands, although rich in “CSPs”, are not involved in chemosensory functions. We propose renaming the “CSPs” to “4CSPs” (4-Cysteine Soluble Proteins) to clarify their role, avoiding confusion with proteins also found in wings, hemolymph, and eggs. This report highlights studies related to insecticide resistance and lipid transport and expands on potential intracellular functions, strongly indicating non-chemosensory features of 4CSPs. Additionally, we show a significant correlation between 4CSPs and mucins, translation initiation factors, and actin complex proteins, reinforcing the proposal to rename “CSPs” and consider developmental pattern, tissue distribution, and intracellular localization. Full article

The paradigm of craniomaxillofacial (CMF) reconstruction is shifting from traditional bone grafting and biochemical adjuncts toward a nucleomechanical framework that leverages the cell nucleus as a mechanosensitive organelle. By utilizing computer-aided design and computer-aided manufacturing (CAD/CAM)-derived scaffolds with 10 µm micropillar arrays and specific interfacial stiffness (25–40 kPa), surgeons can physically manipulate the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex to achieve a nuclear aspect ratio above 2.5. This structural deformation mechanically expands nuclear pores to trigger cytoskeletal and molecular responses, such as Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) translocation. Resultantly, this physical tension pulls open chromatin fibers to activate master osteogenic regulators like RUNX2, effectively bypassing the risks and limitations associated with supraphysiologic growth factor delivery (e.g., rhBMP-2). Clinically, translating these principles involves moving away from absolute rigid internal fixation toward advanced resorbable biomaterials that permit controlled micro-motions (100–200 µm) under functional masticatory loads. This review provides a structured synthesis of the field, outlining deterministic topographic criteria, clinical boundary conditions, and the potential strategies needed to overcome age-related mechanosensory blockades. Ultimately, we establish a multidisciplinary framework that bridges precision bioengineering with native oral and maxillofacial surgical realities to drive living, biophysically mediated bone repair. Full article

Leptobotia elongata, a rare freshwater fish endemic to China, frequently exhibits retarded ovarian development under artificial captivity, severely constraining large-scale reproduction. This study evaluated the effects of combined dietary supplementation with fish oil (FO), soybean phospholipids (PLs), and vitamin E (VE) on ovarian development through a 6-month feeding trial. Hematoxylin and eosin staining revealed that oocytes in the mixed lipid group (MIX: FO + PL + VE) advanced to developmental stage III, whereas oocytes in the control group (CON) were predominantly arrested at stages I–II. Transcriptomic analysis identified 1393 differentially expressed genes (651 upregulated, 742 downregulated). Upregulated genes were enriched in nucleolus- and nuclear pore-related cellular components and RNA-binding molecular functions, indicating enhanced ribosome biogenesis capacity. Downregulated genes were concentrated in DNA damage repair pathways and Mediator complex-mediated transcriptional regulation, suggesting alleviation of oxidative stress. Protein–protein interaction network analysis identified mphosph10, utp11, nat10, emg1, and ftsj3 as core hub genes. Additionally, 44 differentially expressed transcription factors were identified, with Forkhead (forkhead.38), GATA (gata.4), and MYB (myb.40) significantly upregulated, indicating activation of a pro-developmental transcriptional program. These findings provide a theoretical basis for precision lipid nutrition formulation in L. elongata fish diets. Full article

Patients with Liver Hepatocellular carcinoma (LIHC) have a poor prognosis due to late-stage diagnosis and the limited efficacy of drug treatments. Dysregulation of nuclear pore complex (NPC) components, particularly nucleoporins (NUPs), may play a role in tumor progression. However, the specific role of NUP205 in LIHC has not been comprehensively investigated. We evaluated the expression, prognostic significance, epigenetic regulation, microRNA(miRNA) interactions, drug sensitivity, and biological functions of NUP205 in LIHC. Comprehensive bioinformatics analyses were performed using publicly available databases and web-based analysis platforms, including The Cancer Genome Atlas (TCGA), UALCAN, and the Kaplan–Meier Plotter (KM Plotter), among others. In vitro validation was performed using small interfering RNA (siRNA)-mediated knockdown of NUP205 in HepG2 cells, followed by quantitative reverse transcription PCR (RT-qPCR), apoptosis assay and wound-healing assay. NUP205 expression was significantly elevated in patients with LIHC and was associated with advanced clinicopathological features and poor prognosis. Promoter hypomethylation and miRNAs were identified as regulatory mechanisms influencing NUP205 expression. Increased NUP205 levels were associated with resistance to multiple chemotherapeutic agents. NUP205 knockdown significantly reduced messenger RNA (mRNA) expression in HepG2 and PLC/PRF/5 cells, and also reduced the expression of Transmembrane protein 209 (TMEM209) in HepG2 cells and improved sensitivity to doxorubicin. NUP205 expression was consistently associated with adverse clinicopathological features, poor prognosis, and altered drug sensitivity in LIHC. Integrative analyses suggest that NUP205 dysregulation may be linked to epigenetic and miRNA-associated regulatory mechanisms. These findings support NUP205 as a candidate prognostic biomarker and a potential regulatory factor in LIHC, warranting further mechanistic and protein-level validation. Further research is necessary to fully elucidate its underlying mechanisms and potential clinical applications. Full article

Nuclear mechanics and mechanotransduction are involved in the migration and invasion process, such as those in which the cells need to deform themselves to pass through constrictions. Specifically, properties like nuclear softness, viscoelasticity, plasticity (like nuclear pore complexes) and deformability are critical in cancer and its malignant progression. The nucleus represents a physical barrier for the migration and invasion in dense 3D extracellular matrix (ECM) scaffolds. Therefore, the deformability of the nucleus seems to determine the migration limit in circumstances where the enzymatic remodeling of the surroundings is impaired. There are still significant knowledge gaps regarding effects of nuclear deformation during cancer dissemination. It seems that nuclear deformation can alter gene transcription, induce alternative splicing processes, impact nuclear envelope rupture, nuclear pore complex dilatation, damage the DNA, and increase the genomic instability. These mechanically induced alterations can in turn impact the migratory behavior of the cancer cells. The stiffness of the nucleus relies on the condensation of chromatin, and the nuclear lamina, which consists of a network of intermediate filaments underneath the nuclear envelope. All of this is discussed in the review and it is argued that nuclear deformability is universally found in various cancer types. Another focus is placed on the nuclear envelope proteins like emerin, and the SUN-KASH complex and how they contribute to the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, which consequently couples the nucleus and the cytoskeleton. It is argued that this connection is crucial for force transmission, which governs nuclear stiffness dynamically, depending on the force applied. In this review, recent findings are described that couple ECM-induced nuclear mechanosensing and mechanotransduction with the migration and invasion of cancer cells. Moreover, it is suspected that changes in the mechanosensory characteristics of the cell nucleus could play a pivotal part in the malignancy of cancer cells and the heterogeneity of tumors. Finally, it is discussed what impact the individual elements of the nucleus offer to mechanically alter cellular migration and invasion in cancer and its malignant progression. Full article

The p53 tumor suppressor, a key transcription factor, acts as a cellular stress sensor that regulates hundreds of genes involved in responses to DNA damage, oxidative stress, and ischemia. Through these actions, p53 can arrest cell cycle, initiate DNA repair, or trigger cell death. In addition to its nuclear functions, p53 can translocate to mitochondria to promote apoptosis. Studies using isolated mitochondria have suggested that p53 drives the voltage-dependent anion channel (VDAC1) into high molecular mass complexes to mediate apoptosis. VDAC1 is a central regulator of cellular energy production and metabolism and also an essential player in apoptosis, induced by various apoptotic stimuli and stress conditions. We previously demonstrated that VDAC1 oligomerization, induced by various apoptosis stimuli and stress conditions, forms a large pore that enables cytochrome c release from mitochondria, thereby promoting apoptotic cell death. In this study, we show that p53 interacts with VDAC1, modulates its expression levels, and promotes VDAC1 oligomerization-dependent apoptosis. Using purified proteins, we found that p53 directly binds VDAC1, as revealed by microscale thermophoresis and by experiments using bilayer-reconstituted VDAC1, in which p53 reduced VDAC1 channel conductance. Furthermore, overexpression of p53 in p53-null cells or in cells expressing wild-type p53 increased VDAC1 expression and induced VDAC1 oligomerization even in the absence of apoptotic stimuli. Together, these findings identify VDAC1 as a direct p53 target whose expression, oligomerization, and pro-apoptotic activity are regulated by p53. They also reinforce the central role of VDAC1 oligomerization in apoptosis. Full article

Low-complexity domains (LCDs) are protein regions characterized by a simple amino acid composition and low sequence complexity, as they are typically composed of repeats or a limited set of a few amino acids. Historically dismissed as “garbage sequences”, these regions are now acknowledged as critical functional elements. This review systematically explores the structural characteristics, biological functions, pathological roles, and research methodologies associated with LCDs. Structurally, LCDs are marked by intrinsic disorder and conformational dynamics, with their amino acid composition (e.g., G/Y-rich, Q-rich, S/R-rich, P-rich) dictating structural tendencies (e.g., β-sheet formation, phase separation ability). Functionally, LCDs mediate protein–protein interactions, drive liquid–liquid phase separation (LLPS) to form biomolecular condensates, and play roles in signal transduction, transcriptional regulation, cytoskeletal organization, and nuclear pore transportation. Pathologically, LCD dysfunction—such as aberrant phase separation or aggregation—is implicated in neurodegenerative diseases (e.g., ALS, AD), cancer (e.g., Ewing sarcoma), and prion diseases. We also summarize the methodological advances in LCD research, including biochemical (CD, NMR), structural (cryo-EM, HDX-MS), cellular (fluorescence microscopy), and computational (MD simulations, AI prediction) approaches. Finally, we highlight current challenges (e.g., structural heterogeneity, causal ambiguity of phase separation) and future directions (e.g., single-molecule techniques, AI-driven LCD design, targeted therapies). This review provides a comprehensive perspective on LCDs, illuminating their pivotal roles in cellular physiology and disease, and offering insights for future research and therapeutic development. Full article

Endothelial cell proliferation, migration, and intercellular interactions for blood vessel formation require coordinated signaling by a myriad of molecules. Following endothelial cell activation by growth factors and cytokines, a variety of signaling molecules are activated on the surface and transported intracellularly by TM4SF1-enriched microdomains (TMEDs), 100–300 nm diameter protein–lipid complexes recruited by the transmembrane protein TM4SF1. TMEDs internalize via microtubules from the cell surface toward the microtubule-organizing center (MTOC) and then enter the nucleus via nuclear pores (see Graphic Illustration). This internalization pathway permits delivery of activated proteins and other signaling molecules from the cell surface to the nucleus, which directly translates extracellular stimuli to modulation of gene expression. Molecules transported by this route include phospholipase C, gamma 1 (PLCγ1), histone deacetylase 6 (HDAC6), and importins. In the absence of TMEDs, endothelial cells lose the ability to divide into cultures in vitro and to support blood vessel formation in mouse embryos in vivo. We liken TMEDs to cable cars, which take in passengers at the cell surface, travel along microtubule cables, and deliver their passengers to various locations, including the “city center”, the nucleus. This commentary aims to elucidate the functions of TMEDs in endothelial cells, to show that cells, like busy cities, need efficient transport systems to deliver molecules to the destinations where they perform their cellular functions. TMEDs offer a novel and curated transport system providing selected molecules with access to the nucleus. Full article

Abalone are highly susceptible to haliotid herpesvirus 1 (HaHV1), the causative agent of abalone viral ganglioneuritis (AVG), a re-emerging disease responsible for significant mortality events in both wild and farmed populations. Currently, there are no effective antiviral treatments or preventive measures available against HaHV1, which is partly due to the limited understanding of the immune responses and viral pathogenesis in this non-model marine invertebrate. This highlights the urgent need for novel intervention strategies, including investigations into the molecular mechanisms underlying HaHV1 infection. In other herpesviruses, the large tegument protein UL36 plays a crucial role in transporting the viral capsid to the host cell’s nuclear pore complex (NPC), mediated by N-terminal nuclear localization signals (NLSs). However, the nuclear import mechanism of UL36 homologue (UL36h) in HaHV1 remains largely uncharacterized. In this study, we identified and functionally characterized the NLS motif within HaHV1 UL36h and elucidated its interactions with the importin alpha (IMPα) nuclear import receptor. Through a combination of high-resolution crystallography and quantitative binding assays, we determined the key residues responsible for binding to IMPα and demonstrated isoform-specific variations in binding affinity. Our biochemical and structural analyses confirmed key interactions within the NLS that are essential for IMPα interactions. These findings advance our molecular understanding of HaHV1 host interactions and pave the way for the development of targeted antiviral strategies against abalone herpesvirus infection. Full article

Polybrominated diphenyl ethers (PBDEs) are natural products with potent antimicrobial and antineoplastic activity. We have previously shown that the polybrominated diphenyl ether bromoxib (4,5,6-tribromo-2-(2′,4′-dibromophenoxy) phenol), isolated from the marine sponge Dysidea species, exhibits a strong cytotoxic potential in leukemia and lymphoma cells by targeting mitochondrial metabolism. Here, using a mass spectrometric thermal proteome profiling (TPP) approach, we observed that bromoxib induces a rapid reduction in the levels of 19 nucleoporins (NUPs) that are part of the nuclear pore complex (NPC). This apparently affected the functionality of the NPC, as evidenced by the bromoxib-mediated inhibition of the nuclear translocation and subsequent gene reporter activity of transcription factors such as nuclear factor of activated T cells (NFAT) and nuclear factor κB (NF-κB). In addition, bromoxib inhibited the nuclear export of the mRNA of the human immunodeficiency virus transactivator of transcription (HIV-Tat) and the subsequent import of the HIV-Tat protein into the nucleus as determined by the decrease in Tat-dependent gene reporter luciferase activity. Inhibition of nuclear mRNA-export also affected expression of the short-lived anti-apoptotic Bcl-2 protein Mcl-1, which has been shown to induce apoptosis. Thus, its ability to target both mitochondrial metabolism and the NPC renders bromoxib a promising anticancer agent. Full article

Gle1 functions as a regulator of Dbp5, a DEAD-box-containing RNA helicase that is a component of the nuclear pore complex. In association with Gle1 and inositol hexakisphosphate (IP6), ADP-bound Dbp5 facilitates the release of RNA. The RNA-bound Dbp5 undergoes ATP hydrolysis and is activated by Gle1 in the presence of IP6. The formation of a ternary complex involving Dbp5, Gle1, and the nucleoporin Nup159 promotes ADP secretion and prevents RNA recombination. To date, several complex structures of Gle1 with its binding partners have been described; however, the structure of unbound Gle1 remains elusive. To investigate the structural features associated with complex formation, the crystal structure of N-terminally truncated Gle1 from Debaryomyces hansenii (DhGle1ΔN) was determined at a resolution of 1.5 Å. The DhGle1ΔN protein comprises 13 α-helices. Structural comparisons with homologs, all of which have been characterized in various complexes, revealed no significant conformational changes. However, several distinct secondary structural elements were identified in α1, α3, α4, and α8. This study may provide valuable insights into the architecture of yeast Gle1 proteins and their interactions with Dbp5, which is crucial for understanding the regulation of mRNA export. Full article

In the last decades, the study of many nuclear envelope components in Dictyostelium amoebae has revealed conserved mechanisms of nuclear envelope dynamics that root back unexpectedly deep into the eukaryotic tree of life. In this review, we describe the state of the art in nuclear envelope research in this organism starting from early work on nuclear pore complexes to characterization of the first true lamin in a non-metazoan organism and its associated nuclear envelope transmembrane proteins, such as the HeH-family protein Src1 and the LINC complex protein Sun1. We also describe the dynamic processes during semi-closed mitosis, including centrosome insertion into the nuclear envelope, and processes involved in the restoration of nuclear envelope permeability around mitotic exit and compare them to the situation in cells with open or fully closed mitosis. Full article

Viruses frequently exploit the host’s nucleocytoplasmic trafficking machinery to facilitate their replication and evade immune defenses. By encoding specialized proteins and other components, they strategically target host nuclear transport receptors (NTRs) and nucleoporins within the spiderweb-like inner channel of the nuclear pore complex (NPC), enabling efficient access to the host nucleus. This review explores the intricate mechanisms governing the nuclear import and export of viral components, with a focus on the interplay between viral factors and host determinants that are essential for these processes. Given the pivotal role of nucleocytoplasmic shuttling in the viral life cycle, we also examine therapeutic strategies aimed at disrupting the host’s nuclear transport pathways. This includes evaluating the efficacy of pharmacological inhibitors in impairing viral replication and assessing their potential as antiviral treatments. Furthermore, we emphasize the need for continued research to develop targeted therapies that leverage vulnerabilities in nucleocytoplasmic trafficking. Emerging high-resolution techniques, such as advanced imaging and computational modeling, are transforming our understanding of the dynamic interactions between viruses and the NPC. These cutting-edge tools are driving progress in identifying novel therapeutic opportunities and uncovering deeper insights into viral pathogenesis. This review highlights the importance of these advancements in paving the way for innovative antiviral strategies. Full article

Hepatitis B virus (HBV) is a major global health concern, affecting millions of people worldwide. HBV is part of the hepadnaviridae family and one of the primary causes of acute and chronic liver infections, leading to conditions such as cirrhosis and hepatocellular carcinoma (HCC). Understanding the intracellular transport and genome repair mechanisms of HBV is crucial for developing new drugs, which—in combination with immune modulators—may contribute to potential cures. This review will explore the current knowledge of HBV intracytoplasmic and nuclear transport, as well as genome repair processes, while drawing comparisons to other viruses with nuclear replication. Full article

Background/Objectives: Changes in nuclear morphology, alterations to the nuclear pore complex (NPC), including loss, aggregation, and dysfunction of nucleoporins (Nups), and nucleocytoplasmic transport (NCT) abnormalities have become hallmarks of neurodegenerative diseases. Previous RNA sequencing data utilizing knockdown of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) identified enrichment for pathways and changes in RNAs related to nuclear morphology and showed differential expression of key nuclear targets. This suggests that dysfunction of hnRNP A1, which is observed in neurodegenerative diseases, may contribute to abnormalities in nuclear morphology, NPC, and NCT. Methods: We performed knockdown of hnRNP A1 in Neuro-2A cells, a neuronal cell line, to examine nuclear morphology, NPC, and NCT. Results: First, we examined nuclear morphology using Lamin B, wherein we observed increased nuclear envelope abnormalities in cells with hnRNP A1 knockdown as compared to control. To quantify changes in Lamin B, we designed and validated an automated computer-based model, which quantitatively confirmed our observations. Next, we investigated the impact of hnRNP A1 knockdown on components of the NPC and NCT. In line with the previous literature, we found changes in Nups, including altered distribution and reduced protein expression, as well as disrupted NCT. Finally, we validated our findings in multiple sclerosis (MS) brains, a disease with a significant neurodegenerative component caused by hnRNP A1 dysfunction, where neuronal nuclear envelope alterations were significantly increased as compared to controls. Conclusions: Together, these data implicate hnRNP A1 as an important contributor to nuclear morphology, Nup expression and distribution, and NCT and suggest that hnRNP A1 dysfunction may lead to defects in these processes in neurodegenerative diseases. Full article