Regulation of delta-aminolevulinic acid dehydratase by krüppel-like factor 1

PLoS One. 2012;7(10):e46482. doi: 10.1371/journal.pone.0046482. Epub 2012 Oct 3.

Abstract

Krüppel-like factor 1(KLF1) is a hematopoietic-specific zinc finger transcription factor essential for erythroid gene expression. In concert with the transacting factor GATA1, KLF1 modulates the coordinate expression of the genes encoding the multi-enzyme heme biosynthetic pathway during erythroid differentiation. To explore the mechanisms underpinning KLF1 action at the gene loci regulating the first 3 steps in this process, we have exploited the K1-ERp erythroid cell line, in which KLF1 translocates rapidly to the nucleus in response to treatment with 4-OH-Tamoxifen (4-OHT). KLF1 acts as a differentiation-independent transcriptional co-regulator of delta-aminolevulinic acid dehydratase (Alad), but not 5-aminolevulinate synthase gene (Alas2) or porphobilinogen deaminase (Pbgd). Similar to its role at the β-globin promoter, KLF1 induces factor recruitment and chromatin changes at the Alad1b promoter in a temporally-specific manner. In contrast to these changes, we observed a distinct mechanism of histone eviction at the Alad1b promoter. Furthermore, KLF1-dependent events were not modulated by GATA1 factor promoter co-occupancy alone. These results not only enhance our understanding of erythroid-specific modulation of heme biosynthetic regulation by KLF1, but provide a model that will facilitate the elucidation of novel KLF1-dependent events at erythroid gene loci that are independent of GATA1 activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • Chromatin Immunoprecipitation
  • DNA Primers
  • Electrophoretic Mobility Shift Assay
  • Histones / metabolism
  • Kruppel-Like Transcription Factors / metabolism*
  • Mice
  • Polymerase Chain Reaction
  • Porphobilinogen Synthase / genetics
  • Porphobilinogen Synthase / metabolism*
  • Promoter Regions, Genetic
  • RNA Polymerase II / metabolism
  • Tamoxifen / analogs & derivatives
  • Tamoxifen / pharmacology

Substances

  • DNA Primers
  • Histones
  • Kruppel-Like Transcription Factors
  • erythroid Kruppel-like factor
  • Tamoxifen
  • afimoxifene
  • RNA Polymerase II
  • Porphobilinogen Synthase

Grants and funding

The authors thank the Cancer Research Foundation, the Satter Foundation and the Hecktman fellowship for funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.