Functional Characterization of drim2, the Drosophila melanogaster Homolog of the Yeast Mitochondrial Deoxynucleotide Transporter

• Published in: The Journal of biological chemistry 2014-03, Vol.289 (11), p.7448-7459
• Main Authors: Da-Rè, Caterina, Franzolin, Elisa, Biscontin, Alberto, Piazzesi, Antonia, Pacchioni, Beniamina, Gagliani, Maria Cristina, Mazzotta, Gabriella, Tacchetti, Carlo, Zordan, Mauro A., Zeviani, Massimo, Bernardi, Paolo, Bianchi, Vera, De Pittà, Cristiano, Costa, Rodolfo
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Animals, Genetically Modified; Bioenergetics; Biological Transport; DNA, Mitochondrial - metabolism; Drosophila; Drosophila melanogaster - genetics; Drosophila melanogaster - metabolism; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Gene Expression Profiling; Mitochondria; Mitochondria - metabolism; Mitochondrial DNA; Mitochondrial Transport; Molecular Sequence Data; Nucleotide; Nucleotide Transport Proteins - genetics; Nucleotide Transport Proteins - metabolism; Nucleotides - chemistry; Oligonucleotide Array Sequence Analysis; Oxygen Consumption; RNA Interference; RNA, Double-Stranded - metabolism; Saccharomyces cerevisiae Proteins - genetics; Sequence Homology, Amino Acid
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M113.543926

The CG18317 gene (drim2) is the Drosophila melanogaster homolog of the Saccharomyces cerevisiae Rim2 gene, which encodes a pyrimidine (deoxy)nucleotide carrier. Here, we tested if the drim2 gene also encodes for a deoxynucleotide transporter in the fruit fly. The protein was localized to mitochondria. Drosophila S2R+ cells, silenced for drim2 expression, contained markedly reduced pools of both purine and pyrimidine dNTPs in mitochondria, whereas cytosolic pools were unaffected. In vivo drim2 homozygous knock-out was lethal at the larval stage, preceded by the following: (i) impaired locomotor behavior; (ii) decreased rates of oxygen consumption, and (iii) depletion of mtDNA. We conclude that the Drosophila mitochondrial carrier dRIM2 transports all DNA precursors and is essential to maintain mitochondrial function. Background: Carrier-mediated influx of cytosolic deoxynucleotides is a major source of precursors for mitochondrial DNA synthesis. Results: dRIM2 is required to maintain normal deoxynucleotide pools in Drosophila mitochondria, and its knock-out is lethal at the larval stage. Conclusion: dRIM2 is a deoxynucleotide carrier and is essential to maintain mitochondrial function. Significance: Our data provide the first animal model of RIM2 deficiency.