Cry toxins produced by Bacillus thuringiensis (Bt) are insecticidal proteins widely used in insect control. Recently, it was shown that ATP-binding cassette transporter proteins (ABC) such as ABCC2, ABCC3, ABCG1 and ABCA2 are implicated in the insecticidal action of Cry toxins as putative receptors. However, the transcriptional regulators involved in the expression of ABC transporter genes remain unknown. Sequence analysis of promoter regions of ABCC2 gene from Helicoverpa armigera and ABCC3 gene from Spodoptera litura Sl-HP cultured cells, revealed the potential participation of Forkhead box protein A (FOXA), a transcription factor that regulates the expression of genes through remodeling chromatin. To determine if FOXA was involved in regulating expression of ABCC2 and ABCC3 genes, the expression of FOXA, ABCC2 and ABCC3 was compared in Sl-HP cells that are sensitive to Cry1Ac toxin with those in S. frugiperda Sf9 cells that are not sensitive to the toxin. Expression levels of those genes were significantly higher in Sl-HP than in Sf9 cells. Transient expression of FOXA in Sf9 cells activated ABCC2 and ABCC3 transcription, which directly correlated with enhanced Cry1Ac-susceptibility in these cells. Silencing of FOXA gene expression by RNAi in H. armigera larvae resulted in a decreased expression of ABCC2 and ABCC3 without affecting expression of other Cry toxin receptor genes such as alkaline phosphatase, aminopeptidase or cadherin. Silencing of FOXA gene expression also resulted in a Cry1Ac-tolerant phenotype since lower mortality and higher pupation rate were observed in diet containing Cry1Ac protoxin in comparison with the control group. These results demonstrate that FOXA up-regulates expression of the Cry1Ac-toxin receptor ABCC2 and ABCC3 genes, and that lower FOXA expression correlates with tolerance to Cry toxin in cell lines and in lepidopteran larvae.
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http://dx.doi.org/10.1016/j.ibmb.2017.07.004 | DOI Listing |
Immunol Res
January 2025
Inflammatory Bowel Disease Clinic, Department of Gastroenterology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Vasco de Quiroga #15, Col. Belisario Domínguez Sección XVI, 14080, Mexico City, CPCDMX, Mexico.
The ABCC subfamily contains thirteen members. Nine of these transporters are called multidrug resistance proteins (MRPs). The MRPs have been associated with developing ulcerative colitis (UC).
View Article and Find Full Text PDFPharmaceutics
December 2024
Medical Oncology Department, Hospital de la Santa Creu i Sant Pau, 08041 Barcelona, Spain.
Osteosarcoma is a rare disease, but it is the most frequent malignant bone tumor. Primary treatment consists of preoperative MAP (methotrexate (MTX), doxorubicin and cisplatin) chemotherapy followed by surgery and adjuvant chemotherapy. Pathological response to preoperative chemotherapy is one of the most important prognostic factors, but molecular biomarkers are lacking.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan University, Wuhan 430060, China; Hubei Provincial Center for Disease Control and Prevention & NHC Specialty Laboratory of Food Safety Risk Assessment and Standard Development, Wuhan 430079, China; Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Wuhan University, Wuhan 430072, China. Electronic address:
Prenatal exposure to hazardous environmental pollutants is a critical global concern due to their confirmed presence in umbilical cord blood, indicating the ability of pollutants to cross the placental barrier and expose the fetus to harmful compounds. However, the transplacental transfer efficiencies (TTEs) of many pollutants remain underexplored. Herein, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantitatively analyze 91 environmental pollutants, including 13 bisphenols (BPs), 18 organophosphorus flame retardants (OPFRs), 7 brominated and other flame retardants (BFRs), 34 phthalates (PAEs), and 19 per- and polyfluoroalkyl substances (PFASs), in paired maternal and cord serums.
View Article and Find Full Text PDFPharmacol Ther
November 2024
Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA; Department of Medicine (Nephrology), University of California San Diego, La Jolla, CA 92093, USA. Electronic address:
Biomolecules
April 2024
Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei 184-8588, Tokyo, Japan.
By 2013, it had been shown that the genes cadherin-like receptor (Cad) and ATP-binding cassette transporter subfamily C2 (ABCC2) were responsible for insect resistance to several Cry1A toxins, acting as susceptibility-determining receptors, and many review articles have been published. Therefore, this review focuses on information about receptors and receptor-binding sites that have been revealed since 2014. Since 2014, studies have revealed that the receptors involved in determining susceptibility vary depending on the Cry toxin subfamily, and that binding affinity between Cry toxins and receptors plays a crucial role.
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