Mitochondrial transporter that imports/exports pyrimidine nucleotides into and from mitochondria. Selectively transports uridine, thymidine, guanosine, cytosine and inosine (deoxy)nucleoside di- and triphosphates by an antiport mechanism . May import (deoxy)nucleoside triphosphates in exchange for intramitochondrial (deoxy)nucleoside diphosphates, thus providing precursors necessary for de novo synthesis of mitochondrial DNA and RNA while exporting products of their catabolism . Participates in mitochondrial genome maintenance, regulation of mitochondrial membrane potential and mitochondrial respiration . Upon INS or IGF1 stimulation regulates cell growth and proliferation by controlling mitochondrial DNA replication and transcription, the ratio of mitochondria-to nuclear-encoded components of the electron transport chain resulting in control of mitochondrial ROS production (, ). Participates in dendritic cell endocytosis and may associate with mitochondrial oxidative phosphorylation .
Subcellular locations: Mitochondrion inner membrane
Expressed in the central nervous system. Also expressed in testis and skeletal muscle. Weakly expressed in heart, liver, kidney, prostate, colon and peripheral blood leukocytes.