The N-terminal disordered region of ChsB regulates its efficient transport to the hyphal apical surface in Aspergillus nidulans.

In fungi, the cell wall plays a crucial role in morphogenesis and response to stress from the external environment. Chitin is one of the main cell wall components in many filamentous fungi. In Aspergillus nidulans, a class III chitin synthase ChsB plays a pivotal role in hyphal extension and morphogenesis. However, little is known about post-translational modifications of ChsB and their functional impacts. In this study, we showed that ChsB is phosphorylated in vivo. We characterized strains that produce ChsB using stepwise truncations of its N-terminal disordered region or deletions of some residues in that region and demonstrated its involvement in ChsB abundance on the hyphal apical surface and in hyphal tip localization. Furthermore, we showed that some deletions in this region affected the phosphorylation states of ChsB, raising the possibility that these states are important for the localization of ChsB to the hyphal surface and the growth of A. nidulans. Our findings indicate that ChsB transport is regulated by its N-terminal disordered region.

Two telomere-to-telomere gapless genomes reveal insights into Capsicum evolution and capsaicinoid biosynthesis.

Chili pepper (Capsicum) is known for its unique fruit pungency due to the presence of capsaicinoids. The evolutionary history of capsaicinoid biosynthesis and the mechanism of their tissue specificity remain obscure due to the lack of high-quality Capsicum genomes. Here, we report two telomere-to-telomere (T2T) gap-free genomes of C. annuum and its wild nonpungent relative C. rhomboideum to investigate the evolution of fruit pungency in chili peppers. We precisely delineate Capsicum centromeres, which lack high-copy tandem repeats but are extensively invaded by CRM retrotransposons. Through phylogenomic analyses, we estimate the evolutionary timing of capsaicinoid biosynthesis. We reveal disrupted coding and regulatory regions of key biosynthesis genes in nonpungent species. We also find conserved placenta-specific accessible chromatin regions, which likely allow for tissue-specific biosynthetic gene coregulation and capsaicinoid accumulation. These T2T genomic resources will accelerate chili pepper genetic improvement and help to understand Capsicum genome evolution.

AP-2 complex contributes to hyphal-tip-localization of a chitin synthase in the filamentous fungus Aspergillus nidulans.

Filamentous fungi maintain hyphal growth to continually internalize membrane proteins related to cell wall synthesis, transporting them to the hyphal tips. Endocytosis mediates protein internalization via target recognition by the adaptor protein 2 complex (AP-2 complex). The AP-2 complex specifically promotes the internalization of proteins important for hyphal growth, and loss of AP-2 complex function results in abnormal hyphal growth. In this study, deletion mutants of the genes encoding the subunits of the AP-2 complex (α, ß2, µ2, or σ2) in the filamentous fungus Aspergillus nidulans resulted in the formation of conidiophores with abnormal morphology, fewer conidia, and activated the cell wall integrity pathway. We also investigated the localization of ChsB, which plays pivotal roles in hyphal growth in A. nidulans, in the Δµ2 strain. Quantitative analysis suggested that the AP-2 complex is involved in ChsB internalization at subapical collar regions. The absence of the AP-2 complex reduced ChsB localization at the hyphal tips. Our findings suggest that the AP-2 complex contributes to cell wall integrity by properly localizing ChsB to the hyphal tips.

Network pharmacology and molecular docking study on the mechanism of colorectal cancer treatment using Xiao-Chai-Hu-Tang.

BACKGROUND AND OBJECTIVE: We aimed to predict the targets and signal pathways of Xiao-Chai-Hu-Tang (XCHT) in the treatment of colorectal cancer (CRC) based on network pharmacology, just as well as to further analyze its anti-CRC material basis and mechanism of action. METHODS: We adopted Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and Traditional Chinese Medicine Integrated Database (TCMID) databases to screen the active ingredients and potential targets of XCHT. CRC-related targets were retrieved by analyzing published microarray data (accession number GSE110224) from the Gene Expression Omnibus (GEO) database. The common targets were used to construct the "herb-active ingredient-target" network using the Cytoscape 3.8.0 software. Next, we constructed and analyzed protein-to-protein interaction (PPI) using BisoGenet and CytoNCA plug-in in Cytoscape. We then performed Gene Ontology (GO) functional and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analyses of target genes using the R package of clusterProfiler. Furthermore, we used the AutoDock Tools software to conduct molecular docking studies on the active ingredients and key targets to verify the network pharmacological analysis results. RESULTS: We identified a total of 71 active XCHT ingredients and 20 potential anti-CRC targets. The network analysis revealed quercetin, stigmasterol, kaempferol, baicalein, and acacetin as potential key compounds, and PTGS2, NR3C2, CA2, and MMP1 as potential key targets. The active ingredients of XCHT interacted with most CRC disease targets. We showed that XCHT's therapeutic effect was attributed to its synergistic action (multi-compound, multi-target, and multi-pathway). Our GO enrichment analysis showed 46 GO entries, including 20 biological processes, 6 cellular components, and 20 molecular functions. We identified 11 KEGG signaling pathways, including the IL-17, TNF, Toll-like receptor, and NF-kappa B signaling pathways. Our results showed that XCHT could play a role in CRC treatment by regulating different signaling pathways. The molecular docking experiment confirmed the correlation between five core compounds (quercetin, stigmasterol, kaempferol, baicalein, and acacetin) just as well as PTGS2, NR3C2, CA2, and MMP1. CONCLUSION: In this study, we described the potential active ingredients, possible targets, and key biological pathways responsible for the efficacy of XCHT in CRC treatment, providing a theoretical basis for further research.

Synergistic antitumor effect of BRMS1 and sorafenib via inhibition of the PI3K/AKT/mTOR/ERK signaling pathway.

Liver cancer is the fifth most commonly occurring cancer in men and the ninth most commonly occurring cancer in women, worldwide, and is associated with a high mortality rate. Sorafenib is a new inhibitor of multiple kinases, that is regarded as standard treatment for liver cancer. Human breast carcinoma metastasis­suppressor 1 (BRMS1) is a tumor­suppressor gene, that reduces the metastatic ability of tumor cells without affecting their tumorigenicity. In the present study, a model of BRMS1 overexpression and BRMS1 knockdown was established in HepG2 cells. The results revealed that the proliferation of HepG2 cells was inhibited in response to sorafenib treatment using MTT assay. Furthermore, BRMS1 overexpression enhanced the effect of sorafenib. In addition, expression of inflammatory response­related genes was increased, while secretion of angiogenesis­related molecules was decreased, and apoptosis was also activated after sorafenib treatment using qPCR method, and it was further demonstrated that this effect was mediated by inhibition of the PI3K/AKT/mTOR/ERK signaling pathway using western blot analysis. In conclusion, overexpression of BRMS1 potentiated the effect of sorafenib via PI3K/AKT/mTOR/ERK signaling, while knockdown of BRMS1 expression attenuated this effect. These findings may present a novel therapeutic strategy for liver cancer.

Casein Kinase 2 Interacting Protein-1 Suppresses Glioma Cell Proliferation via Regulating the AKT/GSK3ß/ß-Catenin Pathway.

OBJECTIVE: Casein kinase 2 interacting protein-1 (CKIP-1) has exhibited multiple functions in regulating cell proliferation, apoptosis, differentiation, and cytoskeleton. CKIP-1 also plays an important role as a critical regulator in tumorigenesis. The aim of this study is to further examine the function of CKIP-1 in glioma cells. METHODS: The expression level of CKIP-1 protein was determined in gliomas tissues and cell lines by immunohistochemistry stain and western blotting while the association of CKIP-1 expression with prognosis was analyzed by Kaplan-Meier method and compared by log-rank test. CKIP-1 was overexpressed or silenced in gliomas cell lines. CCK-8, colony formation assay, and BrdU incorporation assay were used to determine cell proliferation and DNA synthesis. Cell cycle and apoptosis rate were determined with fluorescence-activated cell sorting (FACS) method. Then, expression of key members in AKT/GSK3ß/ß-catenin pathway was detected by western blot analysis. RESULTS: In the present study, we reported new evidence that CKIP-1 was reversely associated with the proliferation of glioma cells and survival in glioma patients. Additionally, the overexpressed CKIP-1 significantly inhibited glioma cell proliferation. Further experiments revealed that CKIP-1 functioned through its antiproliferative and proapoptotic activity in glioma cells. Importantly, mechanistic investigations suggested that CKIP-1 sharply suppressed the activity of AKT by inhibiting the phosphorylation, markedly downregulated the phosphorylated GSK3ß at Ser9, and promoted ß-catenin degradation. CONCLUSIONS: Overall, our results provided new insights into the clinical significance and molecular mechanism of CKIP-1 in glioma, which indicated CKIP1 might function as a therapeutic target for clinical treatment of glioma.