A Direct HDAC4-MAP Kinase Crosstalk Activates Muscle Atrophy Program

► HDAC4 targets the AP1 but not MEF2 transcription program in neurogenic muscle atrophy ► HDAC4 stimulates AP1 activity by activating MAP kinase signaling ► HDAC4 activates the MAPK cascade by promoting the deacetylation a MAP3K, MEKK2 ► The HDAC4-MAPK-AP1 signaling cascade is essential for neurogenic muscle atrophy