Gfi-1B promoter remains associated with active chromatin marks throughout erythroid differentiation of human primary progenitor cells

Stem Cells. 2009 Sep;27(9):2153-62. doi: 10.1002/stem.151.

Abstract

Growth Factor Independent-1B (Gfi-1B) is a transcriptional repressor that plays critical roles in the control of erythropoiesis and megakaryopoiesis. Gfi-1B expression was described to be repressed by an autoregulatory feedback control loop. Here, we show that Gfi-1 transcription is positively regulated early after induction of erythroid differentiation and remains highly active to late erythroblasts. Using chromatin immunoprecipitation assays in CD34+ cells from human cord blood, we found that Gfi-1 and GATA-2 in immature progenitors and then Gfi-1B and GATA-1 in erythroblasts are bound to the Gfi-1B promoter as well as to the promoter of c-myc, a known Gfi-1B target gene. Surprisingly, this Gfi-1/GATA-2-Gfi-1B/GATA-1 switch observed at erythroblast stages is associated to an increase in the Gfi-1B transcription whereas it triggers repression of c-myc transcription. Accordingly, analysis of chromatin modification patterns shows that HDAC, CoREST, and LSD1 are recruited to the c-myc promoter leading to appearance of repressive chromatin marks. In contrast, the Gfi-1B promoter remains associated with a transcriptionally active chromatin configuration as highlighted by an increase in histone H3 acetylation and concomitant release of the LSD1 and CoREST corepressors. The repressive function of Gfi-1B therefore depends on the nature of the proteins recruited to the target gene promoters and on chromatin modifications. We conclude that Gfi-1B behaves as a lineage-affiliated gene with an open chromatin configuration in multipotent progenitors and sustained activation as cells progress throughout erythroid differentiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Differentiation
  • Cell Line
  • Chromatin / metabolism*
  • Chromatin Immunoprecipitation
  • Co-Repressor Proteins
  • Erythroid Cells / cytology*
  • Erythroid Cells / metabolism*
  • GATA1 Transcription Factor / metabolism
  • GATA2 Transcription Factor / metabolism
  • Genetic Vectors
  • Histone Demethylases / metabolism
  • Humans
  • Lentivirus
  • Nerve Tissue Proteins / metabolism
  • Polymerase Chain Reaction
  • Promoter Regions, Genetic / genetics*
  • Protein Binding
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-myc / genetics
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism*
  • Transfection

Substances

  • Chromatin
  • Co-Repressor Proteins
  • GATA1 Transcription Factor
  • GATA1 protein, human
  • GATA2 Transcription Factor
  • GFI1B protein, human
  • MYC protein, human
  • Nerve Tissue Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-myc
  • RCOR1 protein, human
  • Repressor Proteins
  • Histone Demethylases
  • KDM1A protein, human