- The autoimmune regulator protein has transcriptional transactivating properties and interacts with the common coactivator CREB-binding protein. Pitkänen, J., Doucas, V., Sternsdorf, T., Nakajima, T., Aratani, S., Jensen, K., Will, H., Vähämurto, P., Ollila, J., Vihinen, M., Scott, H.S., Antonarakis, S.E., Kudoh, J., Shimizu, N., Krohn, K., Peterson, P. J. Biol. Chem. (2000)