MAP3K12-binding inhibitory protein 1 (MBIP) is a 39kD protein high expression in the heart and lung. It is a component of the ADA2A-containing complex (ATAC) complex, a complex with histone acetyltransferase activity on histones H3 and H4, and composed of CSRP2BP, KAT2A, TADA2L, TADA3L, ZZ3, MBIP, WDR5, YEATS2, CCDC101 and DR1. In the complex, it probably interacts directly with KAT2A, CSRP2BP and WDR5. It’s function to inhibit the MAP3K12 activity to induce the activation of the JNK/SAPK pathway.