Nucleolar protein 7 (NOL7)

Nucleolar protein 7 (NOL7) is a nucleolar-localized, RNA-binding protein that serves essential roles in ribosome biogenesis by promoting early pre-rRNA accumulation and 5′ETS pre-18S rRNA processing within the small subunit processome[1][4]. NOL7 maintains the integrity of nucleolar structure and regulates cell growth rates[2][3][4]. It functions as a tumor suppressor through both gene expression and post-transcriptional regulation, notably stabilizing antiangiogenic mRNAs such as thrombospondin-1[3][4]. NOL7 is often genetically inactivated or downregulated in cancers, and its depletion induces nucleolar stress, leading to cell cycle arrest and upregulation of TP53 and CDKN1A[1]. Recent research also implicates NOL7/PQBP3 variants in neuronal senescence via nuclear membrane preservation, and mutations are associated with rare neurodevelopmental disorders such as Renpenning syndrome[3][4]. As a multifaceted protein essential for ribosome biogenesis and normal cell viability—especially in cancer cell lines—NOL7 is emerging as both a biomarker and a potential therapeutic target in oncology and ribosomopathies[1][3][4].

Other names

U3 small nucleolar RNA-associated protein NOL7C6orf90NOP27RARG-1dJ223E5.2nucleolar protein of 27 kDaPQBP3polyglutamine binding protein 3retinoic acid repressible protein

Induction of nucleolar stress response upon NOL7 depletion, affecting cell cycle and apoptosis pathways (TP53, CDKN1A upregulation). Stabilization of antiangiogenic mRNAs (e.g., thrombospondin-1) via 3′ UTR binding, enhancing their expression.