| Abstract |
Identification of longevity mutants is crucial for genetic approach to dissect the molecular mechanism of aging and longevity determination. In Drosophila melanogaster, several mutations have been shown to extend the longevity: methuselah encoding a putative G-protein coupled receptor, Indy encoding a sodium dicarboxylate cotransporter, chico encoding insulin receptor substrate, and InR encoding the insulin-like receptor. Extended longevity phenotypes were also observed in transgenic flies overexpressing antioxidant enzymes, Cu/Zn superoxide dismutase and Catalase, Cu/Zn SOD only, or a molecular chaperone, hsp70. Pleiotropism of mutations is a limitation associated with conventional mutagenesis for efficient detection of longevity determination genes. Using a conditional misexpression system, we identified Drosophila POSH (DPOSH), a scaffold protein containing RING finger and four SH3 domains, whose ubiquitous overexpression in adult stage extends the longevity. Neural-specific overexpression of DPOSH is sufficient to extend the longevity, whereas overexpression in non-neural tissues during development induces apoptosis through activation of JNK/SAPK pathway.
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