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Article: Expression of deoxynucleotide carrier is not associated with the mitochondrial DNA depletion caused by anti-HIV dideoxynucleoside analogs and mitochondrial dNTP uptake

TitleExpression of deoxynucleotide carrier is not associated with the mitochondrial DNA depletion caused by anti-HIV dideoxynucleoside analogs and mitochondrial dNTP uptake
Authors
Issue Date2005
PublisherAmerican Society for Pharmacology and Experimental Therapeutics. The Journal's web site is located at http://www.molpharm.org
Citation
Molecular Pharmacology, 2005, v. 67 n. 2, p. 408-416 How to Cite?
AbstractOur previous studies suggested that the dNTP/dNDP transporter systems that exist in mitochondria for transporting dNTP/dNDP from the cytoplasm to the mitochondria for mitochondrial DNA (mtDNA) synthesis play a critical role in delayed cytotoxicity of anti-human immunodeficiency virus (HIV) dideoxynucleoside analogs in mitochondria. A protein, termed mitochondrial deoxynucleotide carrier (DNC), based on its ability to transport dNTPs in reconstituted proteoliposomes, was recently isolated. Lacking cellular information to substantiate DNC's involvement in the delayed cytotoxicity of dideoxynucleoside analogs, we expressed DNC and reconstituted it into proteoliposomes. The Km values for dNTPs uptake by reconstituted DNC were in the millimolar range, which is a thousandfold higher than that of the physiological level. Furthermore, we found that overexpressing DNC (wt and G177A-mutated DNC) in RKO cells did not sensitize the cells to the mtDNA depletion caused by β-D-2′,3′-dideoxycytidine (ddC), 2′,3′-didehydro-2′,3′-dideoxythymidine, and 2′,3′-dideoxyinosine or affect the mtDNA recovery rate after ddC treatment. Mitochondria isolated from DNC-overexpressing cells did not significantly differ from that isolated from RKO cells in terms of the rate of uptake or the incorporation of dTTP into mitochondria DNA. Down-regulation of DNC expression by small interfering RNA was also ineffective in changing the action of dideoxynucleoside analogs on the mtDNA depletion and the rate of dTTP uptake into isolated mitochondria. Down-regulation of both DNC and thymidine kinase-2 also did not cause mtDNA depletion. We conclude that DNC does not play an important role in the delayed cytotoxicity (mtDNA depletion) of anti-HIV dideoxynucleoside analogs and dNTPs uptake into mitochondria.
Persistent Identifierhttp://hdl.handle.net/10722/167889
ISSN
2015 Impact Factor: 3.931
2015 SCImago Journal Rankings: 2.047
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorLam, Wen_US
dc.contributor.authorChen, Cen_US
dc.contributor.authorRuan, Sen_US
dc.contributor.authorLeung, CHen_US
dc.contributor.authorCheng, YCen_US
dc.date.accessioned2012-10-08T03:12:34Z-
dc.date.available2012-10-08T03:12:34Z-
dc.date.issued2005en_US
dc.identifier.citationMolecular Pharmacology, 2005, v. 67 n. 2, p. 408-416en_US
dc.identifier.issn0026-895Xen_US
dc.identifier.urihttp://hdl.handle.net/10722/167889-
dc.description.abstractOur previous studies suggested that the dNTP/dNDP transporter systems that exist in mitochondria for transporting dNTP/dNDP from the cytoplasm to the mitochondria for mitochondrial DNA (mtDNA) synthesis play a critical role in delayed cytotoxicity of anti-human immunodeficiency virus (HIV) dideoxynucleoside analogs in mitochondria. A protein, termed mitochondrial deoxynucleotide carrier (DNC), based on its ability to transport dNTPs in reconstituted proteoliposomes, was recently isolated. Lacking cellular information to substantiate DNC's involvement in the delayed cytotoxicity of dideoxynucleoside analogs, we expressed DNC and reconstituted it into proteoliposomes. The Km values for dNTPs uptake by reconstituted DNC were in the millimolar range, which is a thousandfold higher than that of the physiological level. Furthermore, we found that overexpressing DNC (wt and G177A-mutated DNC) in RKO cells did not sensitize the cells to the mtDNA depletion caused by β-D-2′,3′-dideoxycytidine (ddC), 2′,3′-didehydro-2′,3′-dideoxythymidine, and 2′,3′-dideoxyinosine or affect the mtDNA recovery rate after ddC treatment. Mitochondria isolated from DNC-overexpressing cells did not significantly differ from that isolated from RKO cells in terms of the rate of uptake or the incorporation of dTTP into mitochondria DNA. Down-regulation of DNC expression by small interfering RNA was also ineffective in changing the action of dideoxynucleoside analogs on the mtDNA depletion and the rate of dTTP uptake into isolated mitochondria. Down-regulation of both DNC and thymidine kinase-2 also did not cause mtDNA depletion. We conclude that DNC does not play an important role in the delayed cytotoxicity (mtDNA depletion) of anti-HIV dideoxynucleoside analogs and dNTPs uptake into mitochondria.en_US
dc.languageengen_US
dc.publisherAmerican Society for Pharmacology and Experimental Therapeutics. The Journal's web site is located at http://www.molpharm.orgen_US
dc.relation.ispartofMolecular Pharmacologyen_US
dc.subject.meshAnti-Hiv Agents - Chemistry - Pharmacologyen_US
dc.subject.meshCell Lineen_US
dc.subject.meshDna, Mitochondrial - Genetics - Metabolismen_US
dc.subject.meshDideoxynucleosides - Chemistry - Pharmacologyen_US
dc.subject.meshDown-Regulation - Drug Effects - Physiologyen_US
dc.subject.meshHumansen_US
dc.subject.meshMembrane Transport Proteins - Biosynthesis - Geneticsen_US
dc.subject.meshThymine Nucleotides - Biosynthesis - Geneticsen_US
dc.titleExpression of deoxynucleotide carrier is not associated with the mitochondrial DNA depletion caused by anti-HIV dideoxynucleoside analogs and mitochondrial dNTP uptakeen_US
dc.typeArticleen_US
dc.identifier.emailLeung, CH:duncanl@hkucc.hku.hken_US
dc.identifier.authorityLeung, CH=rp00730en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1124/mol.104.007120en_US
dc.identifier.pmid15539640-
dc.identifier.scopuseid_2-s2.0-13444261490en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-13444261490&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume67en_US
dc.identifier.issue2en_US
dc.identifier.spage408en_US
dc.identifier.epage416en_US
dc.identifier.isiWOS:000226412900008-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridLam, W=7203021943en_US
dc.identifier.scopusauthoridChen, C=16634902200en_US
dc.identifier.scopusauthoridRuan, S=8323796600en_US
dc.identifier.scopusauthoridLeung, CH=7402612570en_US
dc.identifier.scopusauthoridCheng, YC=36041844200en_US

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