CREB-binding protein cooperates with transcription factor GATA-1 and is required for erythroid differentiation

CREB-binding protein cooperates with transcription factor GATA-1 and is required for erythroid differentiation

^*Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA 19104; Departments of ^†Cell Biology and ^§Pediatrics, Children’s Hospital, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115; and ^‡Institute for Molecular Biology, University of Zurich, Zurich, Switzerland

Contributed by Stuart H. Orkin

Abstract

The transcription factor GATA-1 coordinates multiple events during terminal erythroid cell maturation. GATA-1 participates in the transcription of virtually all erythroid-specific genes, blocks apoptosis of precursor cells, and controls the balance between proliferation and cell cycle arrest. Prior studies suggest that the function of GATA-1 is mediated in part through association with transcriptional cofactors. CREB-binding protein (CBP) and its close relative p300 serve as coactivators for a variety of transcription factors involved in growth control and differentiation. We report here that CBP markedly stimulates GATA-1’s transcriptional activity in transient transfection experiments in nonhematopoietic cells. GATA-1 and CBP also coimmunoprecipitate from nuclear extracts of erythroid cells. Interaction mapping pinpoints contact sites to the zinc finger region of GATA-1 and to the E1A-binding region of CBP. Expression of a conditional form of adenovirus E1A in murine erythroleukemia cells blocks differentiation and expression of endogenous GATA-1 target genes, whereas mutant forms of E1A unable to bind CBP/p300 have no effect. Our findings add GATA-1, and very likely other members of the GATA family, to the growing list of molecules implicated in the complex regulatory network surrounding CBP/p300.

Footnotes

ABBREVIATIONS:

CREB,

cAMP response element-binding protein;

CBP,

CREB-binding protein;

EKLF,

erythroid Krüppel-like factor;

FOG,

friend of GATA-1;

MEL,

murine erythroleukemia;

GST,

glutathione S-transferase;

Cr1 and -2,

conserved region 1 and 2;

DMSO,

dimethyl sulfoxide;

BD,

binding domain;

ER,

estrogen receptor