Abstract: Mitochondria are the main place for cell respiration，and mitochondrial dysfunction causes various human diseases. Here we aimed to explore the function of the Schizosaccharomyces cerevisiae mitochondrial protein SHY1（YGR112W）in homologous protein Shy1 of Schizosaccharomyces pombe. Firstly，we generated the strain Δshy1 of shy1 gene deletion by gene knockout，and examined its phenotype in the non-fermentation medium with glycerol as the sole carbon source. Then，bioinformatics analyses revealed that Shy1 of S. pombe contained the conserved MTS（mitochondrial targeting sequence）of about 30 amino acids at the N-terminus. To further study the localization of Shy1，the location of green fluorescent protein（GFP）was observed by labeling GFP at the C-terminus of Shy1 protein regulated by the nmt1 promoter. Lastly，we detected the influence of the deletion of shy1 on the expression of mitochondrial protein by Western blotting. The results demonstrated that the strain of shy1 gene deletion presented its growing deletion in the non-fermentation medium with glycerol as the sole carbon source，and was one with mitochondrial respiratory defect. When GFP was labeled at the C terminus of Shy1 protein regulated by the nmt1 promoter，the location of Shy1 protein was in the mitochondria as the green fluorescence was observed. Moreover，the results of Western blotting revealed that the expression of protein related to mitochondria resulted from the shy1 gene deletion was dramatically declined. Therefore，these findings indicate that Shy1 is localized in mitochondria and is obligatory for mitochondrial respiratory chain to play ordinary function in S. pombe.

Key words: mitochondria, Schizosaccharomyce pombe, Shy1, respiratory chain