ATP-dependent chaperone, which plays an essential role in the cytoplasmic maturation steps of pre-60S ribosomal particles by promoting the release of shuttling protein RSL24D1/RLP24 from the pre-ribosomal particles. Acts together with SPATA5, C1orf109 ortholog and CINP. ATP + H2O = ADP + H(+) + phosphate Associates with pre-60S ribosomal particles. Interacts with C1orf109 ortholog. Expressed in neurons; also expressed at lower level in astrocytes, oligodendrocytes and microglia. Belongs to the AAA ATPase family. AFG2 subfamily.