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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

Extending lifespan of dMRP4 deficiency by a mild increase in JNK signaling under both paraquat resistance and normal condition.Flies heterozygous for puc (pucE69/+) were significantly resistant to paraquat-induced oxidative stress (A) and had a remarkably longer lifespan under non-stress condition (B) compared to controls. (A) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under paraquat stress was compared to control (w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). Each group represented 180 flies. (B) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under normal condition was compared to controls (dMRP4M2/+ and w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). The mean lifespan (50% mortality) was 48 days for dMRP4M2/M1 (n = 360), 62 days for heterozygous control dMRP4M2/+ (n = 360), and 67 days for w1118 (n = 300), 83 days for pucE69/+, dMRP4M2/+ (n = 320), and 79 days for pucE69/+, dMRP4M2/M1 (n = 360). The maximum lifespan (90% mortality) was 62 days for dMRP4M2/M1, 75 days for heterozygous control (dMRP4M2/+), 93 days for flies pucE69/+, dMRP4M2/+), 77 days for w1118, and 88 days for flies (pucE69/+, dMRP4M2/M1). (C) The locomotor defect, indicated by negative geotaxis performance, of dMRP4 mutant flies was completely restored by pucE69/+. Each column was derived from a pool of 80–100 male flies with indicated ages. Student's t-test: ** p<0.01, *** p<0.001. Error bars were S.D. (D) A model for role of dMRP4 in JNK-mediated oxidative resistance and lifespan extension. Paraquat-induced oxidative stress (OS) was sensed through JNK and dMRP4, respectively. The OS signaling may then be converged at levels of the AP-1 transcription factors, the major target of JNK, because dMRP4 is necessary and sufficient for transcription of some JNK-dependent antioxidant genes and because genetic manipulation of puc can fully rescue dMRP4 mutant phenotypes under both oxidative and normal conditions. However, it is also possible that dMRP4 is required for JNK to fully respond to OS at any levels upstream of AP-1. Involvement of dMRP4 in regulation of other JNK-independent antioxidant genes cannot be excluded. The solid arrows represent the work from published studies, and dash arrows indicate the work from this study.
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pgen-1004844-g007: Extending lifespan of dMRP4 deficiency by a mild increase in JNK signaling under both paraquat resistance and normal condition.Flies heterozygous for puc (pucE69/+) were significantly resistant to paraquat-induced oxidative stress (A) and had a remarkably longer lifespan under non-stress condition (B) compared to controls. (A) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under paraquat stress was compared to control (w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). Each group represented 180 flies. (B) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under normal condition was compared to controls (dMRP4M2/+ and w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). The mean lifespan (50% mortality) was 48 days for dMRP4M2/M1 (n = 360), 62 days for heterozygous control dMRP4M2/+ (n = 360), and 67 days for w1118 (n = 300), 83 days for pucE69/+, dMRP4M2/+ (n = 320), and 79 days for pucE69/+, dMRP4M2/M1 (n = 360). The maximum lifespan (90% mortality) was 62 days for dMRP4M2/M1, 75 days for heterozygous control (dMRP4M2/+), 93 days for flies pucE69/+, dMRP4M2/+), 77 days for w1118, and 88 days for flies (pucE69/+, dMRP4M2/M1). (C) The locomotor defect, indicated by negative geotaxis performance, of dMRP4 mutant flies was completely restored by pucE69/+. Each column was derived from a pool of 80–100 male flies with indicated ages. Student's t-test: ** p<0.01, *** p<0.001. Error bars were S.D. (D) A model for role of dMRP4 in JNK-mediated oxidative resistance and lifespan extension. Paraquat-induced oxidative stress (OS) was sensed through JNK and dMRP4, respectively. The OS signaling may then be converged at levels of the AP-1 transcription factors, the major target of JNK, because dMRP4 is necessary and sufficient for transcription of some JNK-dependent antioxidant genes and because genetic manipulation of puc can fully rescue dMRP4 mutant phenotypes under both oxidative and normal conditions. However, it is also possible that dMRP4 is required for JNK to fully respond to OS at any levels upstream of AP-1. Involvement of dMRP4 in regulation of other JNK-independent antioxidant genes cannot be excluded. The solid arrows represent the work from published studies, and dash arrows indicate the work from this study.

Mentions: Increasing age is accompanied with physiological decline. The locomotor decline is one of prominent physiological changes as they grow older. The climbing ability, measured by negative geotaxis, of adult fly reflects a function of age in Drosophila[57], [58]. To determine whether the onset of aging associated with dMRP4, we performed a negative geotaxis test for flies with different ages. Although there was no difference in negative geotaxis behavior between 5-days old dMRP4 mutant and wild-type adults, the age-associated functional decline became visible in dMRP4 mutant flies already at day 10 of adulthood, at a time when no mortality was seen regardless of mutant or wild-type controls (Fig. 7C). By age 40 days, although there was a progressive functional decline in the control group, it was clearly worse in dMRP4 mutant groups (w1118 vs dMRP4M2/M1, Fig. 7C). Thus, the functional decline as they aged was faster in dMRP4 mutants than in controls.


A Drosophila ABC transporter regulates lifespan.

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

Extending lifespan of dMRP4 deficiency by a mild increase in JNK signaling under both paraquat resistance and normal condition.Flies heterozygous for puc (pucE69/+) were significantly resistant to paraquat-induced oxidative stress (A) and had a remarkably longer lifespan under non-stress condition (B) compared to controls. (A) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under paraquat stress was compared to control (w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). Each group represented 180 flies. (B) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under normal condition was compared to controls (dMRP4M2/+ and w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). The mean lifespan (50% mortality) was 48 days for dMRP4M2/M1 (n = 360), 62 days for heterozygous control dMRP4M2/+ (n = 360), and 67 days for w1118 (n = 300), 83 days for pucE69/+, dMRP4M2/+ (n = 320), and 79 days for pucE69/+, dMRP4M2/M1 (n = 360). The maximum lifespan (90% mortality) was 62 days for dMRP4M2/M1, 75 days for heterozygous control (dMRP4M2/+), 93 days for flies pucE69/+, dMRP4M2/+), 77 days for w1118, and 88 days for flies (pucE69/+, dMRP4M2/M1). (C) The locomotor defect, indicated by negative geotaxis performance, of dMRP4 mutant flies was completely restored by pucE69/+. Each column was derived from a pool of 80–100 male flies with indicated ages. Student's t-test: ** p<0.01, *** p<0.001. Error bars were S.D. (D) A model for role of dMRP4 in JNK-mediated oxidative resistance and lifespan extension. Paraquat-induced oxidative stress (OS) was sensed through JNK and dMRP4, respectively. The OS signaling may then be converged at levels of the AP-1 transcription factors, the major target of JNK, because dMRP4 is necessary and sufficient for transcription of some JNK-dependent antioxidant genes and because genetic manipulation of puc can fully rescue dMRP4 mutant phenotypes under both oxidative and normal conditions. However, it is also possible that dMRP4 is required for JNK to fully respond to OS at any levels upstream of AP-1. Involvement of dMRP4 in regulation of other JNK-independent antioxidant genes cannot be excluded. The solid arrows represent the work from published studies, and dash arrows indicate the work from this study.
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Related In: Results  -  Collection

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

pgen-1004844-g007: Extending lifespan of dMRP4 deficiency by a mild increase in JNK signaling under both paraquat resistance and normal condition.Flies heterozygous for puc (pucE69/+) were significantly resistant to paraquat-induced oxidative stress (A) and had a remarkably longer lifespan under non-stress condition (B) compared to controls. (A) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under paraquat stress was compared to control (w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). Each group represented 180 flies. (B) The lifespan of dMRP4 mutant flies (dMRP4M2/M1) under normal condition was compared to controls (dMRP4M2/+ and w1118) and puc, dMRP4 double mutant flies (pucE69/+, dMRP4M2/M1). The mean lifespan (50% mortality) was 48 days for dMRP4M2/M1 (n = 360), 62 days for heterozygous control dMRP4M2/+ (n = 360), and 67 days for w1118 (n = 300), 83 days for pucE69/+, dMRP4M2/+ (n = 320), and 79 days for pucE69/+, dMRP4M2/M1 (n = 360). The maximum lifespan (90% mortality) was 62 days for dMRP4M2/M1, 75 days for heterozygous control (dMRP4M2/+), 93 days for flies pucE69/+, dMRP4M2/+), 77 days for w1118, and 88 days for flies (pucE69/+, dMRP4M2/M1). (C) The locomotor defect, indicated by negative geotaxis performance, of dMRP4 mutant flies was completely restored by pucE69/+. Each column was derived from a pool of 80–100 male flies with indicated ages. Student's t-test: ** p<0.01, *** p<0.001. Error bars were S.D. (D) A model for role of dMRP4 in JNK-mediated oxidative resistance and lifespan extension. Paraquat-induced oxidative stress (OS) was sensed through JNK and dMRP4, respectively. The OS signaling may then be converged at levels of the AP-1 transcription factors, the major target of JNK, because dMRP4 is necessary and sufficient for transcription of some JNK-dependent antioxidant genes and because genetic manipulation of puc can fully rescue dMRP4 mutant phenotypes under both oxidative and normal conditions. However, it is also possible that dMRP4 is required for JNK to fully respond to OS at any levels upstream of AP-1. Involvement of dMRP4 in regulation of other JNK-independent antioxidant genes cannot be excluded. The solid arrows represent the work from published studies, and dash arrows indicate the work from this study.
Mentions: Increasing age is accompanied with physiological decline. The locomotor decline is one of prominent physiological changes as they grow older. The climbing ability, measured by negative geotaxis, of adult fly reflects a function of age in Drosophila[57], [58]. To determine whether the onset of aging associated with dMRP4, we performed a negative geotaxis test for flies with different ages. Although there was no difference in negative geotaxis behavior between 5-days old dMRP4 mutant and wild-type adults, the age-associated functional decline became visible in dMRP4 mutant flies already at day 10 of adulthood, at a time when no mortality was seen regardless of mutant or wild-type controls (Fig. 7C). By age 40 days, although there was a progressive functional decline in the control group, it was clearly worse in dMRP4 mutant groups (w1118 vs dMRP4M2/M1, Fig. 7C). Thus, the functional decline as they aged was faster in dMRP4 mutants than in controls.

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