ZYG11B potentiates the antiviral innate immune response by enhancing cGAS-DNA binding and condensation

ZYG11B suppresses multiple enteroviruses by triggering viral VP1 degradation

Enterovirus 71 (EV71) is a major cause of hand, foot, and mouth disease, particularly affecting pediatric populations worldwide. The role of ZYG11B, a CUL2-complex-associated E3 ubiquitin ligase from the Zyg-11 family, in antiviral defense against EV71 remains unclear. To our knowledge, this study is the first to reveal that ZYG11B targets EV71 VP1 for proteasomal degradation via the ubiquitin-proteasome pathway, with CRL2ZYG11B complex activity specifically driving K33-linked ubiquitination. Mass spectrometry and immunoprecipitation analyses confirmed the interaction between ZYG11B and VP1 and identified key domains required for binding both VP1 and CUL2. Comparative analyses showed that VP1 ubiquitination sites are highly conserved across related enteroviruses, including CA6, CA16, and EVD68. Functional assays further demonstrated that ZYG11B restricts these viruses, highlighting its potential as a broad-spectrum antiviral target. These findings establish ZYG11B as a critical effector in host antiviral responses and support its therapeutic potential for managing enterovirus infections.

IMPORTANCE

E3 ubiquitin ligases and deubiquitinases have become important topics of competition between viruses and hosts. Here, we identified CRL2ZYG11B as an E3 ubiquitin ligase complex capable of degrading structural protein VP1 of enteroviruses, making ZYG11B a broad-spectrum antiviral factor. We first proposed the inhibitory effect of ZYG11B on viruses and identified the structural domains of ZYG11B connecting substrates and CUL2, providing new targets for the design of antiviral drugs.

Identification of a non-inhibitory aptameric ligand to CRL2ZYG11B E3 ligase for targeted protein degradation

As a crucial element of proteolysis targeting chimeras (PROTACs), the choice of E3 ubiquitin ligase significantly influences degradation efficacy and selectivity. However, the available arsenal of E3 ligases for PROTAC development remains underexplored, severely limiting the scope of targeted protein degradation. In this study, we identify a non-inhibitory aptamer targeting ZYG11B, a substrate receptor of the Cullin 2-RING ligase complex, as an E3 warhead for targeted protein degradation. This aptamer-based PROTAC platform, termed ZATAC, is facilely produced through bioorthogonal chemistry or self-assembly and shows promise in eliminating several undruggable target proteins, including nucleolin (NCL), SRY-box transcription factor 2 (SOX2), and mutant p53-R175H, underscoring its universality and versatility. To specifically deliver ZATACs into cancer cells, we further develop DNA three-way junction-based ZATACs (3WJ-ZATACs) by integrating an additional aptamer that selectively recognizes the protein overexpressed on the surface of cancer cells. The 3WJ-ZATACs demonstrate in vivo tumor-specific distribution and achieve dual-target degradation, thereby suppressing tumor growth without causing noticeable toxicity. In summary, ZATACs represent a general, modular, and straightforward platform for targeted protein degradation, offering insights into the potential of other untapped E3 ligases.

Emerging regulatory mechanisms and functions of biomolecular condensates: implications for therapeutic targets

Cells orchestrate their processes through complex interactions, precisely organizing biomolecules in space and time. Recent discoveries have highlighted the crucial role of biomolecular condensates-membrane-less assemblies formed through the condensation of proteins, nucleic acids, and other molecules-in driving efficient and dynamic cellular processes. These condensates are integral to various physiological functions, such as gene expression and intracellular signal transduction, enabling rapid and finely tuned cellular responses. Their ability to regulate cellular signaling pathways is particularly significant, as it requires a careful balance between flexibility and precision. Disruption of this balance can lead to pathological conditions, including neurodegenerative diseases, cancer, and viral infections. Consequently, biomolecular condensates have emerged as promising therapeutic targets, with the potential to offer novel approaches to disease treatment. In this review, we present the recent insights into the regulatory mechanisms by which biomolecular condensates influence intracellular signaling pathways, their roles in health and disease, and potential strategies for modulating condensate dynamics as a therapeutic approach. Understanding these emerging principles may provide valuable directions for developing effective treatments targeting the aberrant behavior of biomolecular condensates in various diseases.

ZYG11B participates in the modulation of colorectal cancer cell proliferation and immune infiltration and is a prognostic biomarker

PROPOSE

The biological function of ZYG11B is still unclear, and few studies on ZYG11B in colorectal cancer were reported. The purpose of our research is to detect the biological functions of ZYG11B in colorectal cancer through The Cancer Genome Atlas (TCGA) database online and the vitro cell experiments.

METHODS

The information of ZYG11B in colorectal cancer were downloaded from TCGA database. The bioinformatics analysis has been utilized to examine the expression, functional enrichment, association of immune, clinicopathological characteristics and diagnostic prognostic value. CCK-8 and apoptosis assays have been utilized to identify the abilities of progression and apoptosis. The abilities of invasion and migration were detected by transwell assay.

RESULTS

In contrast to adjacent normal tissues, colorectal cancer tissues exhibited a notably diminished expression of ZYG11B (p < 0.001). Further examination through functional enrichment analysis unveiled the enrichment of various pathways associated with tumor proliferation and apoptosis. The implementation of CCK-8 and apoptosis assays validated the suppressive impact of ZYG11B on the progression of colorectal cancer cells (p < 0.001). A significant positive correlation was found between ZYG11B and Tcm and T helper cells (R ≥ 0.3, p < 0.001). Moreover, the expression of ZYG11B demonstrated a prominent presence among subjects without previous experience of colon polyps (p < 0.05), devoid of lymphatic infiltration (p < 0.01), and age ≤ 65 years (p < 0.01). Additionally, ZYG11B exhibited higher expression levels among patients diagnosed with colorectal adenocarcinoma (p < 0.05). Following the analysis of survival prognosis, it became evident that increased ZYG11B expression correlated with enhanced survival rates (p < 0.01) and the ability to accurately forecast the prognosis and survival of COAD/READ patients.

CONCLUSION

ZYG11B plays a tumor suppressive role in the proliferation process of colorectal cancer and may have a broad application prospect in the diagnosis and prognosis evaluation of colorectal cancer with more study.

Structure of the E3 ligase CRL2-ZYG11B with substrates reveals the molecular basis for N-degron recognition and ubiquitination

ZYG11B is a substrate specificity factor for Cullin-RING ubiquitin ligase (CRL2) involved in many biological processes, including Gly/N-degron pathways. Yet how the binding of ZYG11B with CRL2 is coupled to substrate recognition and ubiquitination is unknown. We present the Cryo-EM structures of the CRL2-ZYG11B holoenzyme alone and in complex with a Gly/N-peptide from the inflammasome-forming pathogen sensor NLRP1. The structures indicate ZYG11B folds into a Leucine-Rich Repeat followed by two armadillo repeat domains that promote assembly with CRL2 and recognition of NLRP1 Gly/N-degron. ZYG11B promotes activation of the NLRP1 inflammasome through recognition and subsequent ubiquitination of the NLRP1 Gly/N-degron revealed by viral protease cleavage. Our structural and functional data indicate that blocking ZYG11B recognition of the NLRP1 Gly/N-degron inhibits NLRP1 inflammasome activation by a viral protease. Overall, we show how the CRL2-ZYG11B E3 ligase complex recognizes Gly/N-degron substrates, including those that are involved in viral protease-mediated activation of the NLRP1 inflammasome.

Structural variant landscapes reveal convergent signatures of evolution in sheep and goats

BACKGROUND

Sheep and goats have undergone domestication and improvement to produce similar phenotypes, which have been greatly impacted by structural variants (SVs). Here, we report a high-quality chromosome-level reference genome of Asiatic mouflon, and implement a comprehensive analysis of SVs in 897 genomes of worldwide wild and domestic populations of sheep and goats to reveal genetic signatures underlying convergent evolution.

RESULTS

We characterize the SV landscapes in terms of genetic diversity, chromosomal distribution and their links with genes, QTLs and transposable elements, and examine their impacts on regulatory elements. We identify several novel SVs and annotate corresponding genes (e.g., BMPR1B, BMPR2, RALYL, COL21A1, and LRP1B) associated with important production traits such as fertility, meat and milk production, and wool/hair fineness. We detect signatures of selection involving the parallel evolution of orthologous SV-associated genes during domestication, local environmental adaptation, and improvement. In particular, we find that fecundity traits experienced convergent selection targeting the gene BMPR1B, with the DEL00067921 deletion explaining ~10.4% of the phenotypic variation observed in goats.

CONCLUSIONS

Our results provide new insights into the convergent evolution of SVs and serve as a rich resource for the future improvement of sheep, goats, and related livestock.

The Golgi Apparatus: A Key Player in Innate Immunity

The Golgi apparatus, long recognized for its roles in protein processing and vesicular trafficking, has recently been identified as a crucial contributor to innate immune signaling pathways. This review discusses our expanding understanding of the Golgi apparatus's involvement in initiating and activating these pathways. It highlights the significance of membrane connections between the Golgi and other organelles, such as the endoplasmic reticulum, mitochondria, endosomes, and autophagosomes. These connections are vital for the efficient transmission of innate immune signals and the activation of effector responses. Furthermore, the article delves into the Golgi apparatus's roles in key immune pathways, including the inflammasome-mediated activation of caspase-1, the cGAS-STING pathway, and TLR/RLR signaling. Overall, this review aims to provide insights into the multifunctional nature of the Golgi apparatus and its impact on innate immunity.

Understanding nucleic acid sensing and its therapeutic applications

Nucleic acid sensing is involved in viral infections, immune response-related diseases, and therapeutics. Based on the composition of nucleic acids, nucleic acid sensors are defined as DNA or RNA sensors. Pathogen-associated nucleic acids are recognized by membrane-bound and intracellular receptors, known as pattern recognition receptors (PRRs), which induce innate immune-mediated antiviral responses. PRR activation is tightly regulated to eliminate infections and prevent abnormal or excessive immune responses. Nucleic acid sensing is an essential mechanism in tumor immunotherapy and gene therapies that target cancer and infectious diseases through genetically engineered immune cells or therapeutic nucleic acids. Nucleic acid sensing supports immune cells in priming desirable immune responses during tumor treatment. Recent studies have shown that nucleic acid sensing affects the efficiency of gene therapy by inhibiting translation. Suppression of innate immunity induced by nucleic acid sensing through small-molecule inhibitors, virus-derived proteins, and chemical modifications offers a potential therapeutic strategy. Herein, we review the mechanisms and regulation of nucleic acid sensing, specifically covering recent advances. Furthermore, we summarize and discuss recent research progress regarding the different effects of nucleic acid sensing on therapeutic efficacy. This study provides insights for the application of nucleic acid sensing in therapy.

Luteolin inhibits herpes simplex virus 1 infection by activating cyclic guanosine monophosphate-adenosine monophosphate synthase-mediated antiviral innate immunity

BACKGROUND

The successive outbreaks of large-scale infectious diseases due to virus infection have been a major threat to human health in recent decades. Herpes simplex virus I (HSV-1) is a widely-disseminated DNA virus that infects the central nervous system to cause herpes labialis, keratitis and herpes simplex virus encephalitis (HSE), resulting in recurrent lifelong clinical or subclinical episodes. Luteolin is a plant flavone that has been extensively used in the treatment of various human diseases, including carcinogenesis, inflammation and chronic degenerative diseases.

PURPOSE

The aim of this study was to investigate the antiviral molecular mechanism of luteolin against HSV-1 infection in vitro and in vivo.

METHODS

The antiviral effect of luteolin in cell lines was examined by viral plaque assay, RT-qPCR, Western blot and time-of-addition assay. The interaction between luteolin and cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) was evaluated by molecular modeling and semi-denaturing detergent agarose gel electrophoresis. The efficacy of luteolin on HSE was evaluated in the HSE mouse model by analyzing weight loss, neurodegenerative symptoms and histopathological scores. Cytokine expression and protein levels were examined by RT-qPCR, Western blot and ELISA.

RESULTS

Luteolin inhibited the early process of HSV-1 infection, without affecting the infection of acyclovir-resistant HSV-1 strains. In addition, luteolin enhanced antiviral type I interferon production and activated the cytoplasmic DNA-sensing cGAS-stimulator of interferon gene (STING) pathway. Luteolin directly bound the active substrate binding site and promoted the oligomerization of cGAS. Luteolin also inhibited HSE-related weight loss, neurodegeneration and neuroinflammation in mice caused by HSV-1 infection. Furthermore, luteolin enhanced type I interferon expression and stimulated the cGAS-STING signaling pathway in vivo.

CONCLUSION

Luteolin inhibited the post-entry process of HSV-1 by activating the cGAS-STING pathway to promote antiviral interferon production. These results provided the rationale for luteolin as a potent cGAS activator and antiviral agent.

GAS-STING: a classical DNA recognition pathways to tumor therapy

Cyclic GMP-AMP synthetase (cGAS), recognized as the primary DNA sensor within cells, possesses the capability to identify foreign DNA molecules along with free DNA fragments. This identification process facilitates the production of type I IFNs through the activator of the interferon gene (STING) which induces the phosphorylation of downstream transcription factors. This action characterizes the most archetypal biological functionality of the cGAS-STING pathway. When treated with anti-tumor agents, cells experience DNA damage that triggers activation of the cGAS-STING pathway, culminating in the expression of type I IFNs and associated downstream interferon-stimulated genes. cGAS-STING is one of the important innate immune pathways,the role of type I IFNs in the articulation between innate immunity and T-cell antitumour immunity.type I IFNs promote the recruitment and activation of inflammatory cells (including NK cells) at the tumor site.Type I IFNs also can promote the activation and maturation of dendritic cel(DC), improve the antigen presentation of CD4+T lymphocytes, and enhance the cross-presentation of CD8+T lymphocytes to upregulating anti-tumor responses. This review discussed the cGAS-STING signaling and its mechanism and biological function in traditional tumor therapy and immunotherapy.

Phase separation in cGAS-STING signaling

Biomolecular condensates formed by phase separation are widespread and play critical roles in many physiological and pathological processes. cGAS-STING signaling functions to detect aberrant DNA signals to initiate anti-infection defense and antitumor immunity. At the same time, cGAS-STING signaling must be carefully regulated to maintain immune homeostasis. Interestingly, exciting recent studies have reported that biomolecular phase separation exists and plays important roles in different steps of cGAS-STING signaling, including cGAS condensates, STING condensates, and IRF3 condensates. In addition, several intracellular and extracellular factors have been proposed to modulate the condensates in cGAS-STING signaling. These studies reveal novel activation and regulation mechanisms of cGAS-STING signaling and provide new opportunities for drug discovery. Here, we summarize recent advances in the phase separation of cGAS-STING signaling and the development of potential drugs targeting these innate immune condensates.