Generation of selenium-rich wheat mutants and exploration of responsive genes for selenium accumulation.

KEY MESSAGE: Salt tolerance, selenium accumulation and expression of the responsive genes were analyzed in the wheat high selenium mutants. Selenium is an essential trace element for the human body, and its deficiency can lead to various diseases such as Keshan disease and large bone disease. Wheat, being a major staple crop, plays a crucial role in providing dietary selenium supplementation to combat this deficiency. Despite progress in understanding the molecular regulation of selenium accumulation in certain crops, the molecular mechanisms governing selenium accumulation-related gene expression in wheat plants remain poorly understood. In this study, three mutant wheat lines with elevated selenium content were identified. Under the treatment of Na2SeO3 or NaCl, the selenium-rich wheat mutants exhibited decreased sensitivity to both selenium and NaCl compared to the wild type. Additionally, there was an increase in the activities of SOD and POD, while the content of MDA decreased. Through qRT-PCR analysis, the expression of selenium-related genes was affected, revealing that some of these genes not only regulate the response of wheat to salt stress, but also play a role in the process of selenium accumulation. The transcriptome results revealed that the important genes encoding glutathione S-transferases, peroxidases, superoxide dismutases, and UDP-glucosyltransferases may function in the regulation of salt tolerance and selenium accumulation in wheat. These findings significantly contribute to the current understanding of the molecular regulation of selenium accumulation in wheat crops, while also offering novel germplasm resources for cultivating selenium-rich and salt-tolerant wheat lines.

The nucleoporin NUP160 and NUP96 regulate nucleocytoplasmic export of mRNAs and participate in ethylene signaling and response in Arabidopsis.

KEY MESSAGE: Arabidopsis nucleoporin involved in the regulation of ethylene signaling via controlling of nucleocytoplasmic transport of mRNAs. The two-way transport of mRNAs between the nucleus and cytoplasm are controlled by the nuclear pore complex (NPC). In higher plants, the NPC contains at least 30 nucleoporins. The Arabidopsis nucleoporins are involved in various biological processes such as pathogen interaction, nodulation, cold response, flowering, and hormone signaling. However, little is known about the regulatory functions of the nucleoporin NUP160 and NUP96 in ethylene signaling pathway. In the present study, we provided data showing that the Arabidopsis nucleoporin NUP160 and NUP96 participate in ethylene signaling-related mRNAs nucleocytoplasmic transport. The Arabidopsis nucleoporin mutants (nup160, nup96-1, nup96-2) exhibited enhanced ethylene sensitivity. Nuclear qRT-PCR analysis and poly(A)-mRNA in situ hybridization showed that the nucleoporin mutants affected the nucleocytoplasmic transport of all the examined mRNAs, including the ethylene signaling-related mRNAs such as ETR2, ERS1, ERS2, EIN4, CTR1, EIN2, and EIN3. Transcriptome analysis of the nucleoporin mutants provided clues suggesting that the nucleoporin NUP160 and NUP96 may participate in ethylene signaling via various molecular mechanisms. These observations significantly advance our understanding of the regulatory mechanisms of nucleoporin proteins in ethylene signaling and ethylene response.

Chemically labeled ThUBD permits rapid and super-sensitive imaging of polyubiquitination signals.

Polyubiquitination signal deliver diverse cellular signal, which have been recognized as a sophisticated ubiquitin code. The perception and transduction of ubiquitination signal depend on the specificity and sensitivity of the ubiquitin-binding domain. Accurate and sensitive detection of polyubiquitination signal is crucial for revealing the dynamic cellular ubiquitin-regulated events. Western blotting (WB) and immunohistochemistry (IHC) are the most widely used biochemical strategies to detect ubiquitination signal on substrates under diverse physiological and pathological conditions. However, anti-ubiquitin antibodies fail to reflect polyubiquitination signal unbiasedly because of their strong preference for K63-linked ubiquitin chains. Herein, we demonstrated that our previously developed tandem hybrid ubiquitin-binding domain (ThUBD) chemically labeled with a reporter group such as horseradish peroxidase (ThUBD-HRP) could significantly improve the robustness and sensitivity of polyubiquitination signal detection. This advanced method was named TUF-WB Plus (TUF-WB+). The TUF-WB+ method significantly increases the sensitivity and accuracy of ubiquitin detection and requires a shorter experimental operation time. Furthermore, it enables the ThUBD-HRP probe to function as a powerful tool for spatial in situ polyubiquitination detection in cells by immunohistochemistry. Our newly developed ThUBD-HRP probe and TUF-WB+ method provide a robust and powerful tool for ubiquitination signal detection with hypersensitivity in an unbiased manner.

Arabidopsis CPR5 plays a role in regulating nucleocytoplasmic transport of mRNAs in ethylene signaling pathway.

KEY MESSAGE: Arabidopsis CPR5 is involved in regulation of ethylene signaling via two different ways: interacting with the ETR1 N-terminal domains, and controlling nucleocytoplasmic transport of ethylene-related mRNAs. The ETR1 receptor plays a predominant role in ethylene signaling in Arabidopsis thaliana. Previous studies showed that both RTE1 and CPR5 can directly bind to the ETR1 receptor and regulate ethylene signaling. RTE1 was suggested to promote the ETR1 receptor signaling by influencing its conformation, but little is known about the regulatory mechanism of CPR5 in ethylene signaling. In this study, we presented the data showing that both RTE1 and CPR5 bound to the N-terminal domains of ETR1, and regulated ethylene signaling via the ethylene receptor. On the other hand, the research provided evidence indicating that CPR5 could act as a nucleoporin to regulate the ethylene-related mRNAs export out of the nucleus, while RTE1 or its homolog (RTH) had no effect on the nucleocytoplasmic transport of mRNAs. Nuclear qRT-PCR analysis and poly(A)-mRNA in situ hybridization showed that defect of CPR5 restricted nucleocytoplasmic transport of mRNAs. These results advance our understanding of the regulatory mechanism of CPR5 in ethylene signaling.

[Advances in molecular function of p62 protein and its role in diseases].

Sequestosome 1 (SQSTM1/p62) is a selective autophagy adaptor protein that plays an important role in the clearance of proteins to be degraded as well as in the maintenance of cellular proteostasis. p62 protein has multiple functional domains, which interact with several downstream proteins to precisely regulate multiple signaling pathways, thereby linking p62 to oxidative defense systems, inflammatory responses and nutrient sensing. Studies have shown that mutation or abnormal expression of p62 is closely related to the occurrence and development of various diseases, including neurodegenerative diseases, tumors, infectious diseases, genetic diseases and chronic diseases. This review summarizes the structural features and molecular functions of p62. Moreover, we systematically introduce its multiple functions in protein homeostasis and regulation of signaling pathways. Furthermore, the complexity and versatility of p62 in the occurrence and development of diseases are summarized, with the aim to provide a reference for understanding the function of p62 protein and facilitating related disease research.

UHRF2 promotes the malignancy of hepatocellular carcinoma by PARP1 mediated autophagy.

Autophagy have critical implications in the proliferation and metastasis of HCC. In the current study, we aimed to explore the underlying mechanisms of UHRF2 regulates HCC cells autophagy and HCC progression. We initially determined the relationship between UHRF2 and HCC autophagy, oncogenicity and patient survival through GSEA database and TCGA database. We mainly investigated the effect of UHRF2 on HCC development and autophagy through western blot, electron microscopy, and immunofluorescence. Functionally, UHRF2 was positively involved in the autophagy activation. Overexpression of UHRF2 reduced apoptosis in HCC cells, and promoted the malignancy phenotype of HCC both in vitro and in vivo. Mechanistically, PRDX1 bound to UHRF2 and upregulated its protein expression to facilitate the biological function of UHRF2 in HCC. Meanwhile, UHRF2 bound to autophagy-related protein PARP1 and upregulated PARP1 protein level. The results showed that UHRF2 promoted autophagy and contributed to the malignant phenotype of HCC by regulating PARP1 protein level. In summary, a novel interaction between PRDX1, UHRF2, and PARP1 was revealed, suggesting that UHRF2 could inspire a potential biomarker and potential therapeutic target for HCC.

Quantitative proteomics revealed the transition of ergosterol biosynthesis and drug transporters processes during the development of fungal fluconazole resistance.

Fungal infections and antifungal resistance are the increasing global public health concerns. Mechanisms of fungal resistance include alterations in drug-target interactions, detoxification by high expression of drug efflux transporters, and permeability barriers associated with biofilms. However, the systematic panorama and dynamic changes of the relevant biological processes of fungal drug resistance acquisition remain limited. In this study, we developed a yeast model of resistance to prolonged fluconazole treatment and utilized the isobaric labels TMT (tandem mass tag)-based quantitative proteomics to analyze the proteome composition and changes in native, short-time fluconazole stimulated and drug-resistant strains. The proteome exhibited significant dynamic range at the beginning of treatment but returned to normal condition upon acquisition drug resistance. The sterol pathway responded strongly under a short time of fluconazole treatment, with increased transcript levels of most enzymes facilitating greater protein expression. With the drug resistance acquisition, the sterol pathway returned to normal state, while the expression of efflux pump proteins increased obviously on the transcription level. Finally, multiple efflux pump proteins showed high expression in drug-resistant strain. Thus, families of sterol pathway and efflux pump proteins, which are closely associated with drug resistance mechanisms, may play different roles at different nodes in the process of drug resistance acquisition. Our findings uncover the relatively important role of efflux pump proteins in the acquisition of fluconazole resistance and highlight its potential as the vital antifungal targets.