A single cis element maintains repression of the key developmental regulator Gata2.
In development, lineage-restricted transcription factors simultaneously promote differentiation while repressing alternative fates. Molecular dissection of this process has been challenging as transcription factor loci are regulated by many trans-acting factors functioning through dispersed cis elements. It is not understood whether these elements function collectively to confer transcriptional regulation, or individually to control specific aspects of activation or repression, such as initiation versus maintenance. Here, we have analyzed cis element regulation of the critical hematopoietic factor Gata2, which is expressed in early precursors and repressed as GATA-1 levels rise during terminal differentiation. We engineered mice lacking a single cis element -1.8 kb upstream of the Gata2 transcriptional start site. Although Gata2 is normally repressed in late-stage erythroblasts, the -1.8 kb mutation unexpectedly resulted in reactivated Gata2 transcription, blocked differentiation, and an aberrant lineage-specific gene expression pattern. Our findings demonstrate that the -1.8 kb site selectively maintains repression, confers a specific histone modification pattern and expels RNA Polymerase II from the locus. These studies reveal how an individual cis element establishes a normal developmental program via regulating specific steps in the mechanism by which a critical transcription factor is repressed.
Snow
Jonathan W
JW
Division of Hematology-Oncology, Children's Hospital Boston, Boston, Massachusetts, United States of America.
Trowbridge
Jennifer J
JJ
Fujiwara
Tohru
T
Emambokus
Nikla E
NE
Grass
Jeffrey A
JA
Orkin
Stuart H
SH
Bresnick
Emery H
EH
D000818:Animals; D020029:Base Pairing / Q000235:genetics; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics; D041905:Erythroid Cells / Q000378:metabolism; D004920:Erythropoiesis / Q000235:genetics; D050989:GATA2 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D018390:Gene Targeting; D056426:Genetic Loci / Q000235:genetics; D006657:Histones / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains; D009698:Nucleoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012319:RNA Polymerase II / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics
D050989:GATA2 Transcription Factor; C494712:Gata2 protein, mouse; D006657:Histones; D009698:Nucleoproteins; D012097:Repressor Proteins; D012319:RNA Polymerase II