Transcription factors GATA-1 and Fli-1 regulate human HOXA10 expression in megakaryocytic cells.
HOXA10 is a member of the HOX family of regulatory genes that are involved in hematopoiesis. Its role in megakaryopoiesis has been suggested by its expression in immature megakaryocytes and by the proliferation of megakaryocyte-primitive blast colonies upon HOXA10 overexpression. We sought to understand the role of HOXA10 in megakaryopoiesis better, by investigating its transcriptional regulation. Analysis of the 5' untranslated region and transfection of promoter/plasmids into human tissue culture cell lines identified transcriptionally active sequences that contain GATA-1 and Ets-1 sites and a putative binding site for its neighboring gene, HOXA11. Gel shift assays confirmed protein-DNA interactions at these sites. Mutation of the GATA-1 and the Ets-1 motifs amplified the expression of HOXA10 in HEL and K562 cells, confirming the importance of these cis-acting elements in regulating HOXA10 expression in megakaryocytic cells. Chromatin immunoprecipitation (ChIP) and chloramphenicol acetyl transferase (CAT) assays confirm that HOXA11 binds to the putative binding site, resulting in repression of HOXA10 expression. These data taken together give insight into the regulation of HOXA10 expression in megakaryocytic differentiation.
Gosiengfiao
Yasmin
Y
Division of Hematology-Oncology-Stem Cell Transplantation, Department of Pediatrics, Children's Memorial Hospital, Feinberg School of Medicine of Northwestern University, Chicago, Illinois 60614, USA.
Horvat
Regina
R
Thompson
Alexis
A
D024506:5' Flanking Region; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D050982:GATA1 Transcription Factor / Q000378:metabolism*; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins / Q000187:drug effects / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008533:Megakaryocytes / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000187:drug effects; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D015534:Trans-Activators
C098179:FLII protein, human; D050982:GATA1 Transcription Factor; C484298:HOXA11 protein, human; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins; D008840:Microfilament Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators; C069634:HOXA10 protein, human