Nuclear matrix association of multiple sequence-specific DNA binding activities related to SP-1, ATF, CCAAT, C/EBP, OCT-1, and AP-1

The association of DNA binding proteins with the nuclear matrix may be related to a functional role of this subcellular structure in chromatin organization and gene regulation. In this study, nuclear matrix preparations from human HeLa S3 cervical carcinoma and rat ROS 17/2.8 osteosarcoma cells were assayed for the presence of DNA binding activities using consensus binding sequences of well-characterized transcription factors as probes. Competition analysis shows that each probe interacts with different nuclear matrix proteins in a sequence-specific manner and that DNA binding activities related to or identical with SP-1, ATF, CCAAT, C/EBP, OCT-1, and AP-1 are present in the nuclear matrix fraction of different cell types