The Role Of Schizosaccharomyces Pombe Mti2 And Ppr10 In Mitochondrial Protein Translation

Mitochondria are commonly found in eukaryotic cells and are the place for oxidative phosphorylation in cells,which involved in the synthesis of ATP and important physiological processes such as cellular material metabolism,energy metabolism,and cell apoptosis.The mtDNA encodes key subunits(Cob 1?Cox1?Cox2?Cox3?Atp6?Atp8?Atp9?Varl)of the respiratory chain system,which are important for ATP production.Mitochondrial translation initiation factors Mti2 and Mti3 of Schizosaccharomyces pombe play important roles in mitochondrial translation.It has been shown that deletion of the translation initiation factor mti2 and the translation activation factorppr10 affects the stability of key proteins that are encoded by mtDNA,and lead to the dysfunction of mitochondria.In this paper,we reported further how Mti2 and Ppr10 works in mitochondrial translation initiation.The experimental results showed that Mti2 is associated with the small subunit of mitoribosome during mitochondrial translation initiation,the translation activator Ppr10 helps Mti2 bind to the small subunit of mitoribosome.Then we explored the key motifs of Mti2 and Ppr10 further,bioinformatics analysis showed that the Insertion Domain of Mti2 and the PPR motifs of Ppr10 may have important roles in the function of Mti2 and Ppr10,respectively.We designed a series of experiments to explore the function of these two motifs for Mti2 and Ppr10.The experimental results showed that both the mti2AInsertion domain strain and the ppr10?motif strain exhibited significant growth defects on non-fermentative media,indicating that mitochondrial function was seriously affected,and both affected the stable levels of key proteins(Cob1,Cox1,Cox2,Cox3,Atp6)of respiratory chain,which are encoded by the mtDNA,suggesting that Insertion Domain and PPR motifs are key motifs for the function of Mti2 and Ppr10,respectively.These studies help us understand mitochondrial translation process in S.pombe better,and also have provided a deeper insight into mitochondrial translation factors.