X-linked intellectual disability gene CUL4B targets Jab1/CSN5 for degradation and regulates bone morphogenetic protein signaling

► Mutations of the CUL4B gene are linked to X-linked intellectual disability. ► Jab1 is identified as a specific substrate for CUL4B E3 ligase. ► Accumulated Jab1 in response to CUL4B deficiency enhances BMP signaling.