Midasin (MDN1)

Nuclear chaperone required for maturation and nuclear export of pre-60S ribosome subunits (PubMed:27814492). Functions at successive maturation steps to get rid of ribosomal factors at critical transition points, first driving the exit of early pre- 60S particles in the nucleolus and then driving late pre-60S particles in the nucleus (By similarity).

In an early point in 60S maturation, mediates the dissociation of the PeBoW complicated (PES1-BOP1-WDR12) from early pre-60S particles, rendering them competent for export from the nucleolus to the nucleoplasm (By similarity). Then recruited to the nucleoplasmic particles through interaction with SUMO-conjugated PELP1 complicated (PubMed:27814492).