May function as a transcriptional corepressor through its interaction with COPS2, negatively regulating the expression of genes involved in neuronal differentiation. Homodimer (By similarity). Interacts with COPS2 (PubMed:12522100). Interacts with THOC7 (By similarity). Interaction with COPS2 may regulate localization to the nucleus. Belongs to the GTP cyclohydrolase I type 2/NIF3 family.