RIOX1

Ribosomal oxygenase 1 is a protein that in humans is encoded by the RIOX1 gene (previously NO66). The protein is involved in ribosome biogenesis and replication and regulation of heterochromatic regions of the nucleus. It is a chromatin regulator, and a regulator of osteoblast differentiation. It is a Jumonji C (JmjC) domain-containing protein in the subgroup of ribosomal oxygenases (ROXs), part of the superfamily of Fe(II) and 2-oxoglutarate (2OG) dependent oxygenases. Ribosomal oxygenase 1 It is a dual-location protein found in the nucleus, nucleolus, and nucleoplasm of the cell. RIOX1 is a single-exon-gene, intronless, and is found across several species. The gene is involved in gene transcription regulation in the nucleus of the cell.Expression of RIOX1 correlates with potential of cancer. Expression levels are shown to closely correlate with the malignant potential of renal cell tumors and colorectal cancer. The gene has been shown to be an oncogenic driver (initiates cancer cell growth and proliferation) of prostate cancer.

Both RIOX1 and RIOX2 (Previously MINA53) modify ribosome proteins through histidine hydroxylation, specifically His 216. The two proteins differ in the presence of the N-terminal extension which is absent in RIOX2. They are both part of the JmjC-domain-containing protein family, which are a part of a class of histone demethylases, which control the structure of chromatin in order to regulate gene expression. JmjC histone demethylases are linked to human diseases, many cases in cancer and neurological disorders. It enables protein demethylase and peptidyl-histidine dioxygenase activity. It also is involved in regulating DNA repair. RIOX1 has a unique N-terminal extension domain, meaning it can have unique interactions with other molecules, in addition to assistance in protein folding. Nuclear distribution of RIOX1 is localized to perichromosomal (specialized chromosome domain containing proteins for certain processes) cytoplasm in metaphase and early anaphase, localized to chromosomes in late anaphase, and localized to prenucleolar bodies in late telophase, during cellular processes of MCF-7 cells.