The AML/CBFα runt transcription factors are key regulators of hematopoietic and bone tissue-specific gene expression. These factors contain a 31-amino acid nuclear matrix targeting signal that supports association with the nuclear matrix. We determined that the AML/CBFα factors must bind to the nuclear matrix to exert control of transcription. Fusing the nuclear matrix targeting signal to the GAL4 DNA binding domain transactivates a genomically integrated GALA responsive reporter gene. These data suggest that AML/CBFα must associate with the nuclear matrix to effect transcription. We used fluorescence labeling of epitopetagged AML-1B (CBFA2) to show it colocalizes with a subset of hyperphosphorylated RNA polymerase II molecules concentrated in loci and linked to the nuclear matrix. This association of AML-1B with RNA polymerase II requires active transcription and a functional DNA binding domain. The nuclear matrix domains that contain AML-1B are distinct from SC35 RNA processing domains. Our results suggest two of the requirements for AML-dependent transcription initiation by RNA polymerase II are association of AML-1B with the nuclear matrix together with specific binding of AML to gene promoters.
|Number of pages
|Proceedings of the National Academy of Sciences of the United States of America
|Published - Feb 17 1998
ASJC Scopus subject areas