Previous studies have shown that the kinase activation loop (KAL) of the oncogenic fusion protein NPM-ALK regulates its overall tyrosine phosphorylation status and tumorigenicity. Using tandem affinity purification-mass spectrometry, we assessed how the KAL of NPM-ALK regulates the phosphorylation status of its individual tyrosines. Using the lysates of GP293 cells transfected with NPM-ALK, our highly reproducible results showed evidence of phosphorylation in all 3 tyrosines in KAL and 8 tyrosines outside KAL. We created 7 KAL mutants, each of which carried a Tyr-to-Phe mutation of >or=1 of the 3 tyrosines in KAL. A complete loss of the 8 phosphotyrosines outside KAL was found in 3 KAL mutants, and their oncogenicity (assessed by cell viability, colony formation, and the ability to phosphorylate effector proteins) was abrogated. A partial loss of the 8 phosphotyrosines was found in 4 KAL mutants, but their oncogenicity did not show simple correlation with the number of residual phosphotyrosines. Tyr-to-Phe mutations of each of the 8 phosphotyrosines outside KAL did not result in a significant decrease in the oncogenicity. In conclusion, we have provided details of how the KAL in NPM-ALK regulates its tyrosine phosphorylation pattern. Our results challenge some of the current concepts regarding the relationship between the tyrosine phosphorylation and oncogenicity of NPM-ALK.
Aspergillus flavus is a common filamentous fungus widely present in the soil, air, and in crops. This facultative pathogen of both animals and plants produces aflatoxins, a group of mycotoxins with strong teratogenic and carcinogenic properties. Peanuts are highly susceptible to aflatoxin contamination and consumption of contaminated peanuts poses serious threats to the health of humans and domestic animals. Currently, the competitive displacement of aflatoxin-producers from agricultural environments by atoxigenic A. flavus is the most effective method of preventing crop aflatoxin contamination. In the current study, 47 isolates of A. flavus collected from peanut samples originating in Shandong Province were characterized with molecular methods and for aflatoxin-producing ability in laboratory studies. Isolates PA04 and PA10 were found to be atoxigenic members of the L strains morphotype. When co-inoculated with A. flavus NRRL3357 at ratios of 1:10, 1:1, and 10:1 (PA04/PA10: NRRL3357), both atoxigenic strains were able to reduce aflatoxin B1 (AFB1) levels, on both culture media and peanut kernels, by up to 90%. The extent to which atoxigenic strains reduced contamination was correlated with the inoculation ratio. Abilities to compete of PA04 and PA10 were also independently verified against local aflatoxin-producer PA37. The results suggest that the two identified atoxigenic strains are good candidates for active ingredients of biocontrol products for the prevention of aflatoxin contamination of peanuts in Shandong Province.
Under conditions in which ingestion of labeled bacteria by PMN is accomplished within 10 min, oxygen consumption continues to increase in a linear fashion up to 20 min, while the HMS increase continues for at least 30 min. These results support a mechanism in which the O2 increase precedes the HMS activation.
Objective: Ferroptosis, a novel form of cell death, is closely associated with excessive iron accumulated within the substantia nigra in Parkinson’s disease (PD). Despite extensive research, the underlying molecular mechanisms driving ferroptosis in PD remain elusive. Here, we employed a bioinformatics and machine learning approach to predict the genes associated with ferroptosis in PD and investigate the interactions between natural products and their active ingredients with these genes. Methods: We comprehensively analyzed differentially expressed genes (DEGs) for ferroptosis associated with PD (PDFerDEGs) by pairing 3 datasets (GSE7621, GSE20146, and GSE202665) from the NCBI GEO database and the FerrDb V2 database. A machine learning approach was then used to screen PDFerDEGs for signature genes. We mined the interacted natural product components based on screened signature genes. Finally, we mapped a network combined with ingredients and signature genes, then carried out molecular docking validation of core ingredients and targets to uncover potential therapeutic targets and ingredients for PD. Results: We identified 109 PDFerDEGs that were significantly enriched in biological processes and KEGG pathways associated with ferroptosis (including iron ion homeostasis, iron ion transport and ferroptosis, etc.). We obtained 29 overlapping genes and identified 6 hub genes (TLR4, IL6, ADIPOQ, PTGS2, ATG7, and FADS2) by screening with two machine learning algorithms. Based on this, we screened 263 natural product components and subsequently mapped the “Overlapping Genes-Ingredients” network. According to the network, top 5 core active ingredients (quercetin, 17-beta-estradiol, glycerin, trans-resveratrol, and tocopherol) were molecularly docked to hub genes to reveal their potential role in the treatment of ferroptosis in PD. Conclusion: Our findings suggested that PDFerDEGs are associated with ferroptosis and play a role in the progression of PD. Taken together, core ingredients (quercetin, 17-beta-estradiol, glycerin, trans-resveratrol, and tocopherol) bind well to hub genes (TLR4, IL6, ADIPOQ, PTGS2, ATG7, and FADS2), highlighting novel biomarkers for PD.