Component of the ribosomal small subunit processome for the biogenesis of ribosomes, functions in pre-ribosomal RNA (pre-rRNA) processing (By similarity). Essential for embryonic development in part through the regulation of p53 pathway. Controls the expansion growth of digestive organs and liver (PubMed:29262616, PubMed:32303961). Also involved in the sympathetic neuronal development (By similarity). Mediates, with CAPN3, the proteasome-independent degradation of p53/TP53 (By similarity). Interacts with CAPN3; the interaction is required for CAPN3 translocation to the nucleolus. Expressed in all tissues tested: brain, small intestine, large intestine, stomach, liver, spleen, thymus, lung, kidney and testes (at protein level). Phosphorylated. Phosphorylation is required to promote p53/TP53 degradation in the nucleolus which promotes cell cycle progression and liver development. Mutant embryos are peri-implantation lethal at E4.5-E5.5 stages (PubMed:29262616, PubMed:32303961). Conditional knockouts in hepatocytes do not show overall differences in liver growth but suffer from liver chronic inflammation (PubMed:32303961). Hepatocytes show nuclei enlargement with nuclear vacuolization (PubMed:32303961). Animals have bile duct hyperplasia and polycystic liver (PubMed:32303961). Males die suddenly after hepatectomy due to overactive inflammatory response (PubMed:32303961). Belongs to the UTP25 family.