title: The phenotypic expression of mitochondrial tRNA-mutations can be modulated by either mitochondrial leucyl-tRNA synthetase or the C-terminal domain thereof.
abstract: Mutations in mitochondrial (mt) DNA determine important human diseases. The majority of the known pathogenic mutations are located in transfer RNA (tRNA) genes and are responsible for a wide range of currently untreatable disorders. Experimental evidence both in yeast and in human cells has shown that the detrimental effects of mt-tRNA point mutations can be attenuated by increasing the expression of the cognate mt-aminoacyl-tRNA synthetases (aaRSs). In addition, constitutive high levels of isoleucyl-tRNA syntethase have been shown to reduce the penetrance of a homoplasmic mutation in mt-tRNA(Ile) in a small kindred. More recently, we showed that the isolated carboxy-terminal domain of human mt-leucyl tRNA synthetase (LeuRS-Cterm) localizes to mitochondria and ameliorates the energetic defect in transmitochondrial cybrids carrying mutations either in the cognate mt-tRNA(Leu(UUR)) or in the non-cognate mt-tRNA(Ile) gene. Since the mt-LeuRS-Cterm does not possess catalytic activity, its rescuing ability is most likely mediated by a chaperon-like effect, consisting in the stabilization of the tRNA structure altered by the mutation. All together, these observations open potential therapeutic options for mt-tRNA mutations-associated diseases.
authors: Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy.
authors: Carla
authors: C
authors: Giordano
authors: National Research Council of Italy, Institute of Molecular Biology and Pathology, Department of Biochemical Sciences, Sapienza University of Rome Rome, Italy.
authors: Veronica
authors: V
authors: Morea
authors: Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy.
authors: Elena
authors: E
authors: Perli
authors: Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy ; Pasteur Institute-Cenci Bolognetti Foundation Rome, Italy.
authors: Giulia
authors: G
authors: d'Amati
keywords: aminoacyl-tRNA synthetase; mitochondria; mitochondrial disease; molecular therapy; mt-tRNA