Ribosome biogenesis protein C1orf109 is 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 [2]. It has been first identified as the downstream target of a protein kinase, casein kinase 2 (CK2) which is upregulated in cancer cells. C1orf109 has been found upregulated in cancer cells and therefore, it has been suggested to be important in the regulation of cancer cell proliferation. The precise mechanism of CK2 targeting C1orf109 is not well characterised [1]. It is found to be localised in the nucleus and cytoplasm [1].

1: Identification and characterization of a novel gene, c1orf109, encoding a CK2 substrate that is involved in cancer cell proliferation. Liu SS, Zheng HX, Jiang HD, He J, Yu Y, Qu YP, Yue L, Zhang Y, Li Y; J Biomed Sci. 2012;19:49. PMID:22548824

2: Labeling of heterochronic ribosomes reveals C1ORF109 and SPATA5 control a late step in human ribosome assembly. Ni C, Schmitz DA, Lee J, Pawlowski K, Wu J, Buszczak M; Cell Rep. 2022;38:110597. PMID:35354024