- Ligand-dependent interactions of coactivators steroid receptor coactivator-1 and peroxisome proliferator-activated receptor binding protein with nuclear hormone receptors can be imaged in live cells and are required for transcription. Llopis, J., Westin, S., Ricote, M., Wang, Z., Cho, C.Y., Kurokawa, R., Mullen, T.M., Rose, D.W., Rosenfeld, M.G., Tsien, R.Y., Glass, C.K., Wang, J. Proc. Natl. Acad. Sci. U.S.A. (2000)