A Functional Reference Map of RNF8 Interactome in Cancers

Abstract

BackgroundRNF8 was an E3 ligase identified as a critical DNA damage-responsive protein. Recently, massive reports showed that RNF8 could be used as an important therapeutic target for cancer chemo/radiotherapy. However, the in-depth understanding of RNF8 remains limited for the lack of its interactome reference map and comprehensive analysis in divergent cancers, which underscore the need to identify the interactome of RNF8 via high-throughput methods. ResultsA two-way identification method based on LC-MS was designed for the identification of RNF8 interactome with high-specificity. By in silico analysis and in vitro validation, we identified a new reference map of RNF8 interactome network containing substantial new targets, such as YBX1, DNMT1, and HDCA1, new biological functions and the gene-disease associations of RNF8. Our results implied a close relationship between RNF8 and neurodegenerative diseases or tumor-infiltrating immune cells using bulk RNA-seq and scRNA-seq datasets. As a proof of concept of our interactome map, we validated the direct binding between RNF8 and YBX1, and showed that RNF8 catalyzed the ubiquitination of YBX. These results demonstrated that RNF8 might be a crucial regulator of YBX1.ConclusionsOur work provides a unique framework for researchers and clinicians who seek to better explore or understand RNF8-regulated biological functions in cancers. This study hopefully will facilitate rational design and further development of anti-RNF8 therapy in cancers.