Activity‐based Proteomic Approaches to Investigate Aging in C. Elegans

Abstract

The elucidation of protein activities dysregulated during the aging process is a vital step toward the discovery of signaling networks and metabolic pathways directly implicated in aging. Genetic studies in the model organism, Caenorhabditis elegans, generated a daf‐2 mutant that has a significantly extended lifespan. The daf‐2‐ gene mutant activates DAF‐16, a transcription factor, which initiates gene expression changes that mediate the life‐extension phenotype of this mutant. Identifying protein‐activity changes that are downstream effects of DAF‐16 activation will illuminate cellular pathways directly implicated in the aging process. We propose to directly monitor protein activity changes using the tools of activity‐based protein profiling. We are focusing our initial efforts on cysteine‐mediated protein activities that encompass a subset of diverse protein classes including proteases, kinases, ubiquitinating proteins, and metabolic enzymes. Combining small‐molecule probes that selectively bind to active members of these enzyme families, together with quantitative mass spectrometrybased proteomics, we are comparing protein activity in daf‐2 and daf‐2/daf‐16 mutant nematodes. Current work is focused on verifying the identity of these dysregulated proteins and understanding the role of these protein activities in slowing down the aging process in daf‐2 nematodes.