Transcriptional coactivator in the bone morphogenetic protein (BMP)-signaling pathway. It positively modulates BMP signaling by interacting with SMAD1 and associating with CBP in the transcription complex. It contributes to the BMP-induced enhancement of cholinergic-neuron-specific gene expression (By similarity). Interacts with SMAD1 and CREB-binding protein (CBP). Forms a protein-DNA complex through its association with SMAD1 (By similarity). Belongs to the ZCCHC12 family.