Abstract
The receptor for advanced glycation end products (RAGE) is a highly expressed cell membrane receptor serving to anchor lung epithelia to matrix components, and it also amplifies inflammatory signaling during acute lung injury. However, mechanisms that regulate its protein concentrations in cells remain largely unknown. Here we show that RAGE exhibits an extended life span in lung epithelia (t½ 6 h), is monoubiquitinated at K374, and is degraded in lysosomes. The RAGE ligand ODN2006, a synthetic oligodeoxynucleotide resembling pathogenic hypomethylated CpG DNA, promotes rapid lysosomal RAGE degradation through activation of protein kinase Cζ (PKCζ), which phosphorylates RAGE. PKCζ overexpression enhances RAGE degradation, while PKCζ knockdown stabilizes RAGE protein levels and prevents ODN2006-mediated degradation. We identify that RAGE is targeted by the ubiquitin E3 ligase subunit F-box protein O10 (FBXO10), which associates with RAGE to mediate its ubiquitination and degradation. FBXO10 depletion in cells stabilizes RAGE and is required for ODN2006-mediated degradation. These data suggest that modulation of regulators involved in ubiquitin-mediated disposal of RAGE might serve as unique molecular inputs directing RAGE cellular concentrations and downstream responses, which are critical in an array of inflammatory disorders, including acute lung injury.-Evankovich, J., Lear, T., Mckelvey, A., Dunn, S., Londino, J., Liu, Y., Chen, B. B., Mallampalli, R. K. Receptor for advanced glycation end products is targeted by FBXO10 for ubiquitination and degradation.