Deletion of PaAif2 and PaAmid2, two genes encoding mitochondrial AIF-like oxidoreductases of Podospora anserina, leads to increased stress tolerance and lifespan extension

Abstract

Wild-type strains of the ascomycete Podospora anserina are characterized by a limited lifespan. Mitochondria play a central role in this ageing process raising the question of whether apoptosis-like processes, which are also connected to mitochondrial function, are involved in the control of the final stage in the fungal life cycle. While a role of two metacaspases in apoptosis and lifespan control was recently demonstrated in P. anserina, virtually nothing is known about the function of the protein family of apoptosis-inducing factors (AIFs). Here we report data about proteins belonging to this family. We demonstrate that the cytosolic members PaAIF1 and PaAMID1 do not affect lifespan. In contrast, loss of PaAIF2 and PaAMID2, which both were localized to mitochondria, are characterized by a significantly increased ROS tolerance and a prolonged lifespan. In addition, deletion of PaAmid2 severely affects sporogenesis. These data identify components of a caspase-independent molecular pathway to be involved in developmental processes and in the induction of programmed cell death in the senescent stage of P. anserina.