SPATA 2 promotes CYLD activity and regulates TNF ‐induced NF ‐κB signaling and cell death

K63‐ and Met1‐linked ubiquitylation are crucial posttranslational modifications for TNF receptor signaling. These non‐degradative ubiquitylations are counteracted by deubiquitinases ( DUB s), such as the enzyme CYLD , resulting in an appropriate signal strength, but the regulation of this process remains incompletely understood. Here, we describe an interaction partner of CYLD , SPATA 2, which we identified by a mass spectrometry screen. We find that SPATA 2 interacts via its PUB domain with CYLD , while a PUB interaction motif ( PIM ) of SPATA 2 interacts with the PUB domain of the LUBAC component HOIP . SPATA 2 is required for the recruitment of CYLD to the TNF receptor signaling complex upon TNFR stimulation. Moreover, SPATA 2 acts as an allosteric activator for the K63‐ and M1‐deubiquitinase activity of CYLD . In consequence, SPATA 2 substantially attenuates TNF ‐induced NF ‐κB and MAPK signaling. Conversely, SPATA 2 is required for TNF ‐induced complex II formation, caspase activation, and apoptosis. Thus, this study identifies SPATA 2 as an important factor in the TNF signaling pathway with a substantial role for the effects mediated by the cytokine.