The lysine acetyltransferase CREB binding protein (CBP) is required for chromatin modification and transcription at many gene promoters. In fixed cells, a large proportion of CBP colocalises to PML or nuclear bodies. Using live cell imaging, we show here that YFP-tagged CBP expressed in HEK293 cells undergoes gradual accumulation in nuclear bodies, some of which are mobile and migrate towards the nuclear envelope. Deletion of a short lysine-rich domain that contains the major SUMO acceptor sites of CBP abrogated its ability to be SUMO modified, and prevented its association with endogenous SUMO-1/PML speckles in vivo. This SUMO-defective CBP showed enhanced ability to co-activate AML1-mediated transcription. Deletion mapping revealed that the SUMO-modified region was not sufficient for targeting CBP to PML bodies, as C-terminally truncated mutants containing this domain showed a strong reduction in accumulation at PML bodies. Fluorescence recovery after photo-bleaching (FRAP) experiments revealed that YFP-CBPΔ998-1087 had a retarded recovery time in the nucleus, as compared to YFP-CBP. These results indicate that SUMOylation regulates CBP function by influencing its shuttling between nuclear bodies and chromatin microenvironments. © 2009 Elsevier Inc. All rights reserved.
Ryan, C. M., Kindle, K. B., Collins, H. M., & Heery, D. M. (2010). SUMOylation regulates the nuclear mobility of CREB binding protein and its association with nuclear bodies in live cells. Biochemical and Biophysical Research Communications, 391(1), 1136–1141. https://doi.org/10.1016/j.bbrc.2009.12.040