Repression of c-kit and its downstream substrates by GATA-1 inhibits cell proliferation during erythroid maturation

Mol Cell Biol. 2005 Aug;25(15):6747-59. doi: 10.1128/MCB.25.15.6747-6759.2005.

Abstract

Stem cell factor (SCF), erythropoietin (Epo), and GATA-1 play an essential role(s) in erythroid development. We examined how these proteins interact functionally in G1E cells, a GATA-1(-) erythroblast line that proliferates in an SCF-dependent fashion and, upon restoration of GATA-1 function, undergoes GATA-1 proliferation arrest and Epo-dependent terminal maturation. We show that SCF-induced cell cycle progression is mediated via activation of the Src kinase/c-Myc pathway. Restoration of GATA-1 activity induced G1 cell cycle arrest coincident with repression of c-Kit and its downstream effectors Vav1, Rac1, and Akt. Sustained expression of each of these individual signaling components inhibited GATA-1-induced cell cycle arrest to various degrees but had no effects on the expression of GATA-1-regulated erythroid maturation markers. Chromatin immunoprecipitation analysis revealed that GATA-1 occupies a defined Kit gene regulatory element in vivo, suggesting a direct mechanism for gene repression. Hence, in addition to its well-established function as an activator of erythroid genes, GATA-1 also participates in a distinct genetic program that inhibits cell proliferation by repressing the expression of multiple components of the c-Kit signaling axis. Our findings reveal a novel aspect of molecular cross talk between essential transcriptional and cytokine signaling components of hematopoietic development.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Cell Differentiation / physiology*
  • Cell Line, Transformed
  • Cell Proliferation*
  • Clone Cells
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / physiology*
  • Erythroid Cells / cytology
  • Erythroid Cells / enzymology*
  • Erythroid Cells / metabolism
  • Erythroid-Specific DNA-Binding Factors
  • Erythropoietin / metabolism
  • GATA1 Transcription Factor
  • Gene Expression Regulation / physiology
  • Growth Inhibitors / biosynthesis
  • Growth Inhibitors / physiology*
  • Mice
  • Proto-Oncogene Proteins c-kit / biosynthesis*
  • Proto-Oncogene Proteins c-kit / genetics
  • Proto-Oncogene Proteins c-kit / metabolism*
  • Proto-Oncogene Proteins c-kit / physiology
  • Repressor Proteins / biosynthesis
  • Repressor Proteins / physiology*
  • Signal Transduction / physiology
  • Stem Cell Factor / metabolism
  • Substrate Specificity
  • Transcription Factors / biosynthesis
  • Transcription Factors / physiology*
  • src-Family Kinases / metabolism

Substances

  • DNA-Binding Proteins
  • Erythroid-Specific DNA-Binding Factors
  • GATA1 Transcription Factor
  • Gata1 protein, mouse
  • Growth Inhibitors
  • Repressor Proteins
  • Stem Cell Factor
  • Transcription Factors
  • Erythropoietin
  • Proto-Oncogene Proteins c-kit
  • src-Family Kinases