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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

dMRP4 is up-regulated in response to oxidative stress.(A) Quantitative RT-PCR analyses of RNA isolated from wild-type flies (w1118) after exposed to paraquat (A), hydrogen peroxide (B,) or hyperoxia (C) for indicated times. Data is showed as means ± S.D. from at least 5 independent experiments. One way ANOVA followed by post hoc t-test: * p<0.05, ** p<0.01, *** p<0.001, ns: No significance (p>0.05).
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pgen-1004844-g001: dMRP4 is up-regulated in response to oxidative stress.(A) Quantitative RT-PCR analyses of RNA isolated from wild-type flies (w1118) after exposed to paraquat (A), hydrogen peroxide (B,) or hyperoxia (C) for indicated times. Data is showed as means ± S.D. from at least 5 independent experiments. One way ANOVA followed by post hoc t-test: * p<0.05, ** p<0.01, *** p<0.001, ns: No significance (p>0.05).

Mentions: To test our hypothesis that the expression of dMRP4 may be regulated by oxidative stress in Drosophila, we first analyzed dMRP4 transcriptional activity in response to oxidative stimuli by feeding flies with paraquat, which generates superoxide in mitochondria [34] and has been widely used as an oxidative stress inducer in vivo. The expression of dMRP4 was strongly induced in wild-type flies fed with 10 mM paraquat for 12 hours (Fig. 1A). Similar induction patterns were observed in parallel with two known oxidative stress-responsive genes [3], [6], [35], puc (puckered) and gstD1 (glutathione s transferase D1). To test whether dMRP4 responds to other oxidative stressors, we analyzed its transcriptional changes in flies treated with hydrogen peroxide as well as hyperoxia. Up-regualtion of dMRP4 was clearly observed after hydrogen peroxide or hyperoxia treatment, in parallel with two known up-regulated markers, gstD1 and hsp22, under these conditions [1] (Fig. 1B–C). These results indicate that Drosophila dMRP4 is a bona fide oxidative stress-responsive gene.


A Drosophila ABC transporter regulates lifespan.

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

dMRP4 is up-regulated in response to oxidative stress.(A) Quantitative RT-PCR analyses of RNA isolated from wild-type flies (w1118) after exposed to paraquat (A), hydrogen peroxide (B,) or hyperoxia (C) for indicated times. Data is showed as means ± S.D. from at least 5 independent experiments. One way ANOVA followed by post hoc t-test: * p<0.05, ** p<0.01, *** p<0.001, ns: No significance (p>0.05).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4256198&req=5

pgen-1004844-g001: dMRP4 is up-regulated in response to oxidative stress.(A) Quantitative RT-PCR analyses of RNA isolated from wild-type flies (w1118) after exposed to paraquat (A), hydrogen peroxide (B,) or hyperoxia (C) for indicated times. Data is showed as means ± S.D. from at least 5 independent experiments. One way ANOVA followed by post hoc t-test: * p<0.05, ** p<0.01, *** p<0.001, ns: No significance (p>0.05).
Mentions: To test our hypothesis that the expression of dMRP4 may be regulated by oxidative stress in Drosophila, we first analyzed dMRP4 transcriptional activity in response to oxidative stimuli by feeding flies with paraquat, which generates superoxide in mitochondria [34] and has been widely used as an oxidative stress inducer in vivo. The expression of dMRP4 was strongly induced in wild-type flies fed with 10 mM paraquat for 12 hours (Fig. 1A). Similar induction patterns were observed in parallel with two known oxidative stress-responsive genes [3], [6], [35], puc (puckered) and gstD1 (glutathione s transferase D1). To test whether dMRP4 responds to other oxidative stressors, we analyzed its transcriptional changes in flies treated with hydrogen peroxide as well as hyperoxia. Up-regualtion of dMRP4 was clearly observed after hydrogen peroxide or hyperoxia treatment, in parallel with two known up-regulated markers, gstD1 and hsp22, under these conditions [1] (Fig. 1B–C). These results indicate that Drosophila dMRP4 is a bona fide oxidative stress-responsive gene.

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