Distinct functions of dispersed GATA factor complexes at an endogenous gene locus

JA Grass, H Jing, SI Kim, ML Martowicz… - … and cellular biology, 2006 - Am Soc Microbiol
JA Grass, H Jing, SI Kim, ML Martowicz, S Pal, GA Blobel, EH Bresnick
Molecular and cellular biology, 2006Am Soc Microbiol
The reciprocal expression of GATA-1 and GATA-2 during hematopoiesis is an important
determinant of red blood cell development. Whereas Gata2 is preferentially transcribed early
in hematopoiesis, elevated GATA-1 levels result in GATA-1 occupancy at sites upstream of
the Gata2 locus and transcriptional repression. GATA-2 occupies these sites in the
transcriptionally active locus, suggesting that a “GATA switch” abrogates GATA-2-mediated
positive autoregulation. Chromatin immunoprecipitation (ChIP) coupled with genomic …
Abstract
The reciprocal expression of GATA-1 and GATA-2 during hematopoiesis is an important determinant of red blood cell development. Whereas Gata2 is preferentially transcribed early in hematopoiesis, elevated GATA-1 levels result in GATA-1 occupancy at sites upstream of the Gata2 locus and transcriptional repression. GATA-2 occupies these sites in the transcriptionally active locus, suggesting that a “GATA switch” abrogates GATA-2-mediated positive autoregulation. Chromatin immunoprecipitation (ChIP) coupled with genomic microarray analysis and quantitative ChIP analysis with GATA-1-null cells expressing an estrogen receptor ligand binding domain fusion to GATA-1 revealed additional GATA switches 77 kb upstream of Gata2 and within intron 4 at+ 9.5 kb. Despite indistinguishable GATA-1 occupancy at− 77 kb and+ 9.5 kb versus other GATA switch sites, GATA-1 functioned uniquely at the different regions. GATA-1 induced histone deacetylation at and near Gata2 but not at the− 77 kb region. The− 77 kb region, which was DNase I hypersensitive in both active and inactive states, conferred equivalent enhancer activities in GATA-1-and GATA-2-expressing cells. By contrast, the+ 9.5 kb region exhibited considerably stronger enhancer activity in GATA-2-than in GATA-1-expressing cells, and other GATA switch sites were active only in GATA-1-or GATA-2-expressing cells. Chromosome conformation capture analysis demonstrated higher-order interactions between the− 77 kb region and Gata2 in the active and repressed states. These results indicate that dispersed GATA factor complexes function via long-range chromatin interactions and qualitatively distinct activities to regulate Gata2 transcription.
American Society for Microbiology