Construction of mitochondrion-targeted telomerase for analysis in Saccharomyces cerevisiae

Telomerase is associated with telomere production and nDNA protection. However, studies by Santos et al. have demonstrated that human telomerase has a mitochondrial entry sequence and in the presence of hydrogen peroxide it has been found inside the mitochondrion and may cause mitochondrial DNA mutations. Saccharomyces cerevisiae contains telomerase, but it does not have the mitochondrial entry sequence. To determine if the presence of telomerase in the mitochondria can induce mutations an experiment was developed in which a mitochondrion entry sequence would be fused to the S. cerevisiae telomerase enzyme. This fusion could then be screened in S. cerevisiae with an ade2 mutation for a simple color assay of mitochondrial activity. To date, no successful transformant has been identified. The frequency of incorrect ligations has been recognized and may indicate that the desired fusion is lethal to E. coli cells.