Mitochondrial nucleic acid binding proteins associated with diseases

Mammalian mitochondrial DNA (mtDNA) exists in structures called nucleoids, which correspond to the configuration of nuclear DNA. Mitochondrial transcription factor A (TFAM), first cloned as an mtDNA transcription factor, is critical for packaging and maintaining mtDNA. To investigate functional aspects of TFAM, we identified many RNA-binding proteins as candidate TFAM interactors, including ERAL1 and p32. In this review, we first describe the functions of TFAM, replication proteins such as polymerase γ and Twinkle, and mitochondrial RNA binding proteins. We describe the role of mitochondrial nucleic acid binding proteins within the mitochondrial matrix and two oxidative phosphorylation-related proteins within the mitochondrial intermembrane space. We then discuss how mitochondrial dysfunction is related to several diseases, including mitochondrial respiratory disease, Miller syndrome and cancer. We also describe p32 knockout mice, which are embryonic lethal and exhibit respiratory chain defects. Miller syndrome is a recessive disorder characterized by postaxial acrofacial dysostosis and caused by a mutation in DHODH. Finally, we explain that p32 and mitochondrial creatine kinase may be novel markers for the progression of prostate cancer.