1430 Autophagy controls the protein composition of hair shafts

Hair shafts are formed by terminal differentiation of hair keratinocytes which synthesize and cross-link keratins keratin-associated proteins. Here we tested the hypothesis that maturation also involves coordinated degradation non-cytoskeletal proteins autophagy. To this end, deleted essential autophagy regulator Atg7 in epidermis skin appendages, including hair, determined proteome from fully autophagy-competent epithelial autophagy-deficient mice. The abrogation led to increased abundance hundreds functionally diverse shafts. Translation initiation factors, tRNA-ligases, ribosomal subunits proteasomes were particularly elevated absence autophagy, indicating a central role regulating multiple steps protein turnover keratinocytes. These results demonstrate depend on for establishing mature composition suggest proteomic analysis may be used diagnosis impaired