Interacts (via C-terminus) with hey1/bc8 (via Orange domain). Uniformly distributed within the cell, but becomes recruited to the nucleus upon binding to hey1/bc8. In adults, expressed at varying levels in different organs including the liver and brain, with highest expression in the testis. Expressed both maternally and zygotically. Expressed in all embryonic stages, with expression increasing during development. Belongs to the CCDC89 family.