A SWI SNF-RELATED CHROMATIN REMODELING COMPLEX, E-RC1, IS REQUIRED FOR TISSUE-SPECIFIC TRANSCRIPTIONAL REGULATION BY EKLF IN-VITRO/

Erythroid Kruppel-like factor (EKLF) is necessary for stage-specific e xpression of the human beta-globin gene. We show that EKLF requires a SWI/SNF-related chromatin remodeling complex, EKLF coactivator-remodel ing complex 1 (E-RC1), to generate a DNase I hypersensitive, transcrip tionally active beta-globin promoter on chromatin templates in vitro. E-RC1 contains BRG1, BAF170, BAF155, and INI1 (BAF47) homologs of yeas t SWI/SNF subunits, as well as a subunit unique to higher eukaryotes, BAF57, which is critical for chromatin remodeling and transcription wi th EKLF. E-RC1 displays functional selectivity toward transcription fa ctors, since it cannot activate expression of chromatin-assembled HIV- 1 templates with the E box-binding protein TFE-3. Thus, a member of th e SWI/SNF family acts directly in transcriptional activation and may r egulate subsets of genes by selectively interacting with specific DNA- binding proteins.