Abstract 4968: Phosphorylation of caspase-8 (Thr263) by ribosomal S6 kinase 2 (RSK2) mediates caspase-8 ubiquitination and stability

The ribosomal S6 kinase 2 (RSK2) is a member of the p90 ribosomal S6 kinase (p90RSK) family of proteins and plays a critical role in proliferation, cell cycle and transformation. Here, we report that RSK2 phosphorylates caspase-8 and Thr263 was identified as a novel caspase-8 phosphorylation site. Phosphorylation of Thr263 is associated with the ubiquitination and degradation of caspase through the proteasome pathway. Results suggested that RSK2 regulates caspase-8 stability through its phosphorylation of this caspase. These data provide a direct link between RSK2 and caspase-8 and identify a novel molecular mechanism for caspase-8 modulation by RSK2. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4968. doi:1538-7445.AM2012-4968