The rapid, massive synthesis of storage proteins that occurs during seed development stresses endoplasmic reticulum (ER) homeostasis, which activates the ER unfolded protein response (UPR). However, how different storage proteins contribute to UPR is not clear. We analysed vegetative tissues of transgenic arabidopsis (Arabidopsis thaliana) plants constitutively expressing the common bean (Phaseolus vulgaris) soluble vacuolar storage protein PHASEOLIN (PHSL) or maize (Zea mays) prolamins (27kD γ-zein or 16kD γ-zein) that participate in forming insoluble protein bodies in the ER. We show that 16kD γ-zein significantly activates the INOSITOL REQUIRING ENZYME1 (IRE1)/BASIC LEUCINE ZIPPER 60 (bZIP60) UPR branch — but not the BASIC LEUCINE ZIPPER 28 (bZIP28) branch or autophagy — leading to induction of major UPR-controlled genes that encode folding helpers that function inside the ER. Protein blot analysis of IMMUNOGLOBULIN-BINDING PROTEIN (BIP) 1 and 2, BIP3, GLUCOSE REGULATED PROTEIN 94 (GRP94), and ER-localized DNAJ family 3A (ERDJ3A) polypeptides confirmed their higher accumulation in the plant expressing 16kD γ-zein. Expression of 27kD γ-zein significantly induced only BIP3 and ERDJ3A transcription even though an increase in GRP94 and BIP1/2 polypeptides also occurred in this plant. These results indicate a significant but weaker effect of 27kD γ-zein compared to 16kD γ-zein, which corresponds with the higher availability of 16kD γ-zein for BIP binding, and indicates subtle protein-specific modulations of plant UPR. None of the analysed genes was significantly induced by PHSL or by a mutated, soluble form of 27kD γ-zein that traffics along the secretory pathway. Such variability in UPR induction may have influenced the evolution of storage proteins with different tissue and subcellular localizations.
ion channels. Here, we describe two different K(þ) currents activated by the application of the oxidant chloramine-T in pre-metastatic IGR39 melanoma cells. Specifically, in whole-cell patch-clamp experiments the addition of 0.5 mM chloramine-T evoked extremely large (up to 80 pA / pF) voltagedependent K(þ)-currents, which were blocked by the addition of 30 mM TEA. In addition, chloramine-T activated a smaller, voltage-independent and TEA-insensitive K(þ) current ( 30 pA / pF). The IGR39 current response to chloramine-T was accompanied by an increase in intracellular calcium concentration. The increase of calcium occurred only in the presence of calcium in the extracellular solution. We are currently investigating the molecular components mediating the chloramine-T activated currents, aiming to unravel if chloramine-T acts directly by oxidation of the relevant potassium channel(s) or indirectly, for example through the oxidation of a further component, likely a calcium permeable channel (e.g. a member of the TRP family) leading to an increase in intracellular calcium. Interestingly, IGR37 cells, metastatic melanoma cells derived from the same patient, do not show any substantial activation of ionic currents upon application of chloramine-T. The presence and the large size of K(þ) currents activated in response to the oxidizing agent IGR39 cells strongly suggest that they play a major role in melanoma progression.
ion channels. Here, we describe two different K(þ) currents activated by the application of the oxidant chloramine-T in pre-metastatic IGR39 melanoma cells. Specifically, in whole-cell patch-clamp experiments the addition of 0.5 mM chloramine-T evoked extremely large (up to 80 pA / pF) voltagedependent K(þ)-currents, which were blocked by the addition of 30 mM TEA. In addition, chloramine-T activated a smaller, voltage-independent and TEA-insensitive K(þ) current ( 30 pA / pF). The IGR39 current response to chloramine-T was accompanied by an increase in intracellular calcium concentration. The increase of calcium occurred only in the presence of calcium in the extracellular solution. We are currently investigating the molecular components mediating the chloramine-T activated currents, aiming to unravel if chloramine-T acts directly by oxidation of the relevant potassium channel(s) or indirectly, for example through the oxidation of a further component, likely a calcium permeable channel (e.g. a member of the TRP family) leading to an increase in intracellular calcium. Interestingly, IGR37 cells, metastatic melanoma cells derived from the same patient, do not show any substantial activation of ionic currents upon application of chloramine-T. The presence and the large size of K(þ) currents activated in response to the oxidizing agent IGR39 cells strongly suggest that they play a major role in melanoma progression.
Background: Vitamin D plays an important role in many normal body functions, including regulation of cell growth, bone formation, inflammation, neuromuscular and immune function. Lower serum levels of 25-hydroxyvitamin D, an index of vitamin D status, are associated with greater risk of cancer. Genetic variants in vitamin D related genes have been linked to breast cancer (BC) risk. These include the vitamin D receptor (VDR) and the GC gene that encodes for the vitamin D binding protein. Aims: To determinate the frequency of 5 single nucleotide polymorphisms (SNPs) of VDR and GC in a large cohort of subjects candidate to BRCA 1/2 genetic testing and to assess any interaction between vitamin D and BRCA pathways on disease outcome. Methods: From 2002 to 2012 blood samples from 1025 subjects with family history of ovarian cancer (OC) or BC were collected after informed consent was signed during the genetic counseling. DNA was extracted from whole EDTA treated blood and Allelic Discrimination (Applied Biosystems’ Taqman assays) of VDR (BsmI, FokI, TaqI, ApaI) and GC SNPs is ongoing. Results: At last follow-up in February 2014 our cohort included 272 unaffected subjects (117 BRCA carriers, 37 WT and 118 true negative) and 753 affected subjects (276 BRCA1/2 carriers, 469 WT and 1 true negative subjects). Amongst BC patients (N = 675), 221 were BRCA carriers, 446 WT, and 8 true negative. Those affected ofBC and OC (N = 27), included 23 BRCA carriers and 4 WT, while OC patients (N = 51) included 32 BRCA carriers and 19 WT. Here we present the preliminary data obtained for VDR and GC SNPs in 833 and 710 subjects, respectively. None of the genotypes deviated from the Hardy-Weinberg equilibrium. At the AACR meeting the genotyping of all subjects will be completed. Conclusions: Our results of vitamin D genotyping will be correlated with BC tumor molecular subtype in affected subjects, and any association with BRCA mutation and outcome will be assessed. The study was funded by IEO Foundation and AVON. Description of vitamin D genetic polymorphisms and their frequenciesSNPsType of polymorphismMinor Allele Frequency (MAF)MAF HapMapHWE Pvalue(1df chi-square test)rs 1544410; VDR BsmITransition C/TT: 0.420.440.50rs2228570; VDR FokITransition A/GA: 0.360.410.72rs731236; VDR TaqITransition A/GC: 0.410.440.52rs7975232; VDR ApaITransversion A/CG: 0.430.430.91rs22282679; GCTransversion G/TG: 0.280.260.52 Citation Format: Valentina Aristarco, Harriet Johansson, Debora Macis, Aliana Guerrieri Gonzaga, Sara Gandini, Davide Serrano, Irene Feroce, Monica Barile, Antonella Puccio, Lorenzo Brocca, Bernardo Bonanni. Associations of Vitamin D related polymorphisms with hereditary breast cancer in 1025 subjects undergoing BRCA 1/2 testing. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1909. doi:10.1158/1538-7445.AM2015-1909
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.