Ring finger protein 1 (RING1) belongs to the RING finger family, members of which encode proteins characterized by a RING domain, a zinc-binding motif related to the zinc finger domain. RING1 can bind DNA and can act as a transcriptional repressor. It is associated with the multimeric polycomb group protein complex. RING1 interacts with the polycomb group proteins BMI1, EDR1, and CBX4, and colocalizes with these proteins in large nuclear domains. It also interacts with the CBX4 protein via its glycine-rich C-terminal domain [taken from NCBI Entrez Gene (Gene ID: 6015)].