- RING1 is associated with the polycomb group protein complex and acts as a transcriptional repressor. Satijn, D.P., Gunster, M.J., van der Vlag, J., Hamer, K.M., Schul, W., Alkema, M.J., Saurin, A.J., Freemont, P.S., van Driel, R., Otte, A.P. Mol. Cell. Biol. (1997)