biostudies-literatureRambaldelli GNIDDK NIH HHSUniversity of TrentoNational Institutes of HealthNIH HHSjcs264096https://www.ebi.ac.uk/biostudies/studies/S-EPMC12450466biostudies-literatureUnknown138(17)NOC1, NOC2 and NOC3 are evolutionarily conserved nucleolar proteins that play an essential role in the maturation and processing of ribosomal RNA (rRNA). NOC1 in Drosophila is necessary to sustain rRNA processing, whereas its depletion leads to impaired polysome formation, reduced protein synthesis and induces apoptosis. In this study, we demonstrated that the RNA-regulatory functions of NOC1 are conserved in vertebrates, where the reduction of CEBPZ, the homolog of NOC1, leads to the accumulation of unprocessed 45S pre-rRNA, a reduction in protein synthesis, and inhibition of cell growth. Gene Ontology and bioinformatic analyses of CEBPZ, NOC2L and NOC3L in tumors highlight a significant correlation between their expression and processes that regulate rRNA processing and ribosomal maturatJournal of cell scienceDrosophila and human cell studies reveal a conserved role for CEBPZ, NOC2L and NOC3L in rRNA processing and tumorigenesis.PMC12450466SC1 DK085047P40 OD018537SC1DK085047Manara VVutera Cuda ABellosta PPenzo MRambaldelli GBertalot GfalseDrosophila and human cell studies reveal a conserved role for CEBPZ, NOC2L and NOC3L in rRNA processing and tumorigenesis.NOC1, NOC2 and NOC3 are evolutionarily conserved nucleolar proteins that play an essential role in the maturation and processing of ribosomal RNA (rRNA). NOC1 in Drosophila is necessary to sustain rRNA processing, whereas its depletion leads to impaired polysome formation, reduced protein synthesis and induces apoptosis. In this study, we demonstrated that the RNA-regulatory functions of NOC1 are conserved in vertebrates, where the reduction of CEBPZ, the homolog of NOC1, leads to the accumulation of unprocessed 45S pre-rRNA, a reduction in protein synthesis, and inhibition of cell growth. Gene Ontology and bioinformatic analyses of CEBPZ, NOC2L and NOC3L in tumors highlight a significant correlation between their expression and processes that regulate rRNA processing and ribosomal maturat2025-01-01T00:00:00Z2025 Sep2026-07-16T03:11:13.687Z2026-07-09T10:31:56.592ZS-EPMC124504664082784110.1242/jcs.264096