Component of the DNA replication complex, which interacts with two kinases, CDK2 and CDC7, thereby providing a functional and physical link between CDK2 and CDC7 during firing of the origins of replication. Regulates ATR-mediated checkpoint signaling in response to DNA damage. Also involved in the cytoplasmic maturation steps of pre-60S ribosomal particles by promoting the release of shuttling protein RSL24D1/RLP24 from the pre-ribosomal particles. Promotes maturation of pre-60S ribosome together with SPATA5, SPATA5L1 and C1orf109. Homodimer. Interacts with CDK2 and CDC7. Interacts with the components of the replication complex, MCM2, MCM3, MCM4, MCM5, MCM6, MCM7 and with ORC2-containing complexes. Interacts with ATRIP. Interacts with CEP152. Associates with pre-60S ribosomal particles. Interacts with C1orf109 ortholog. Binds to nuclear under G1 conditions, and dissociates from chromatin with the start of DNA replication. Phosphorylated by CDC7 but not by CDK2. Belongs to the CINP family.