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A Drosophila ABC transporter regulates lifespan.

Huang H, Lu-Bo Y, Haddad GG - PLoS Genet. (2014)

Bottom Line: MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes.By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition.We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics (Division of Respiratory Medicine), University of California San Diego, La Jolla, California, United States of America.

ABSTRACT
MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

No MeSH data available.


Related in: MedlinePlus

Elevated dMRP4 expression increases oxidative resistance.Overexpression of dMRP4 globally (A and F) or tissue-specifically (C–D), significantly promoted adult fly survival of paraquat (PQ)-induced oxidative stress. Since yolk-Gal4 is expressed specifically in the female fat body, female flies were used in the yolk>dMRP4 experiment (C). Male flies were otherwise used in all other experiments. (H–J) qt-PCR analysis of dMRP4 induction by different Gal4 drivers. Concentrations of paraquat and RU486 used in individual experiment were indicated, except for (F–G) where concentration of RU486 used was 150 ug/ml. Student's t-test was used in (E and F) and ANOVA was used in (D) and (I–J). * p<0.05, ** p<0.01, *** p<0.001. ns: No significance (p>0.05). Sample size: (A) tub5GS>dMRP4[75], n = 160; tub5GS>dMRP4 (+RU), n = 180; (B) tub5GS-Gal4/+[75], n = 160; tub5GS-Gal4/+ (+RU), n = 160; (C) yolk-Gal4/w1118, n = 160; dMRP4/+, n = 160; yolk-Gal4/w1118; dMRP4/+, n = 160; (D) S106>dMRP4[75], n = 180; S106>dMRP4 (+RU), n = 180; (E) S106-Gal4/+[75], n = 160; S106-Gal4/+ (+RU), n = 160. (F) tub5GS>dMRP4[75], n = 200; tub5GS>dMRP4 (+RU), n = 200; (G) tub5GS-Gal4/+[75], n = 200; tub5GS-Gal4/+ (+RU), n = 180.
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pgen-1004844-g004: Elevated dMRP4 expression increases oxidative resistance.Overexpression of dMRP4 globally (A and F) or tissue-specifically (C–D), significantly promoted adult fly survival of paraquat (PQ)-induced oxidative stress. Since yolk-Gal4 is expressed specifically in the female fat body, female flies were used in the yolk>dMRP4 experiment (C). Male flies were otherwise used in all other experiments. (H–J) qt-PCR analysis of dMRP4 induction by different Gal4 drivers. Concentrations of paraquat and RU486 used in individual experiment were indicated, except for (F–G) where concentration of RU486 used was 150 ug/ml. Student's t-test was used in (E and F) and ANOVA was used in (D) and (I–J). * p<0.05, ** p<0.01, *** p<0.001. ns: No significance (p>0.05). Sample size: (A) tub5GS>dMRP4[75], n = 160; tub5GS>dMRP4 (+RU), n = 180; (B) tub5GS-Gal4/+[75], n = 160; tub5GS-Gal4/+ (+RU), n = 160; (C) yolk-Gal4/w1118, n = 160; dMRP4/+, n = 160; yolk-Gal4/w1118; dMRP4/+, n = 160; (D) S106>dMRP4[75], n = 180; S106>dMRP4 (+RU), n = 180; (E) S106-Gal4/+[75], n = 160; S106-Gal4/+ (+RU), n = 160. (F) tub5GS>dMRP4[75], n = 200; tub5GS>dMRP4 (+RU), n = 200; (G) tub5GS-Gal4/+[75], n = 200; tub5GS-Gal4/+ (+RU), n = 180.

Mentions: If dMRP4 is essential for oxidative resistance in Drosophila, an increased dMRP4 expression may increase oxidative resistance in wild-type flies. To test this hypothesis, we used the RU486-system to test the role of dMRP4 overexpressing in paraquat resistance. Adult flies carrying tub5GS>dMRP4, after being fed with RU486 for dMRP4 induction (Fig. 4I), significantly improved survival rates following acute treatment with paraquat (30 mM) compared to control flies (Fig. 4A). Importantly, RU486 feeding itself had no effect on survival under the same condition (Fig. 4B). These experiments underline the protective role of dMRP4 from paraquat challenge. It also implies that this protection does not need dMRP4 to be elevated before reaching adulthood.


A Drosophila ABC transporter regulates lifespan.

Huang H, Lu-Bo Y, Haddad GG - PLoS Genet. (2014)

Elevated dMRP4 expression increases oxidative resistance.Overexpression of dMRP4 globally (A and F) or tissue-specifically (C–D), significantly promoted adult fly survival of paraquat (PQ)-induced oxidative stress. Since yolk-Gal4 is expressed specifically in the female fat body, female flies were used in the yolk>dMRP4 experiment (C). Male flies were otherwise used in all other experiments. (H–J) qt-PCR analysis of dMRP4 induction by different Gal4 drivers. Concentrations of paraquat and RU486 used in individual experiment were indicated, except for (F–G) where concentration of RU486 used was 150 ug/ml. Student's t-test was used in (E and F) and ANOVA was used in (D) and (I–J). * p<0.05, ** p<0.01, *** p<0.001. ns: No significance (p>0.05). Sample size: (A) tub5GS>dMRP4[75], n = 160; tub5GS>dMRP4 (+RU), n = 180; (B) tub5GS-Gal4/+[75], n = 160; tub5GS-Gal4/+ (+RU), n = 160; (C) yolk-Gal4/w1118, n = 160; dMRP4/+, n = 160; yolk-Gal4/w1118; dMRP4/+, n = 160; (D) S106>dMRP4[75], n = 180; S106>dMRP4 (+RU), n = 180; (E) S106-Gal4/+[75], n = 160; S106-Gal4/+ (+RU), n = 160. (F) tub5GS>dMRP4[75], n = 200; tub5GS>dMRP4 (+RU), n = 200; (G) tub5GS-Gal4/+[75], n = 200; tub5GS-Gal4/+ (+RU), n = 180.
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Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4256198&req=5

pgen-1004844-g004: Elevated dMRP4 expression increases oxidative resistance.Overexpression of dMRP4 globally (A and F) or tissue-specifically (C–D), significantly promoted adult fly survival of paraquat (PQ)-induced oxidative stress. Since yolk-Gal4 is expressed specifically in the female fat body, female flies were used in the yolk>dMRP4 experiment (C). Male flies were otherwise used in all other experiments. (H–J) qt-PCR analysis of dMRP4 induction by different Gal4 drivers. Concentrations of paraquat and RU486 used in individual experiment were indicated, except for (F–G) where concentration of RU486 used was 150 ug/ml. Student's t-test was used in (E and F) and ANOVA was used in (D) and (I–J). * p<0.05, ** p<0.01, *** p<0.001. ns: No significance (p>0.05). Sample size: (A) tub5GS>dMRP4[75], n = 160; tub5GS>dMRP4 (+RU), n = 180; (B) tub5GS-Gal4/+[75], n = 160; tub5GS-Gal4/+ (+RU), n = 160; (C) yolk-Gal4/w1118, n = 160; dMRP4/+, n = 160; yolk-Gal4/w1118; dMRP4/+, n = 160; (D) S106>dMRP4[75], n = 180; S106>dMRP4 (+RU), n = 180; (E) S106-Gal4/+[75], n = 160; S106-Gal4/+ (+RU), n = 160. (F) tub5GS>dMRP4[75], n = 200; tub5GS>dMRP4 (+RU), n = 200; (G) tub5GS-Gal4/+[75], n = 200; tub5GS-Gal4/+ (+RU), n = 180.
Mentions: If dMRP4 is essential for oxidative resistance in Drosophila, an increased dMRP4 expression may increase oxidative resistance in wild-type flies. To test this hypothesis, we used the RU486-system to test the role of dMRP4 overexpressing in paraquat resistance. Adult flies carrying tub5GS>dMRP4, after being fed with RU486 for dMRP4 induction (Fig. 4I), significantly improved survival rates following acute treatment with paraquat (30 mM) compared to control flies (Fig. 4A). Importantly, RU486 feeding itself had no effect on survival under the same condition (Fig. 4B). These experiments underline the protective role of dMRP4 from paraquat challenge. It also implies that this protection does not need dMRP4 to be elevated before reaching adulthood.

Bottom Line: MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes.By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition.We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics (Division of Respiratory Medicine), University of California San Diego, La Jolla, California, United States of America.

ABSTRACT
MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling.

No MeSH data available.


Related in: MedlinePlus