E protein dosage influences brain development more than family member identity

J Neurosci Res. 2008 May 15;86(7):1472-81. doi: 10.1002/jnr.21615.


Loss-of-function studies have revealed the role of many basic helix-loop-helix (bHLH) transcription factors at specific points during development; however, the role of E proteins in the development of the nervous system has not been experimentally addressed. E proteins have been speculated to interact selectively with class II bHLH factors to form different neurogenic complexes. In this study, using coimmunoprecipitation in a culture model of neurogenesis (P19 cells), we show that E proteins E12, HEB, and E2-2 interact with neuroD2. Using electrophoretic mobility shift assay and P19 cell culture, we show that these heterodimers bind a neuroD2 preferred E box and induce neurogenesis equally well. We examine the mRNA levels of the three E proteins at 10 time points during brain development and show that E protein gene expression is regulated such that at certain times during development selective interaction between neuroD2 and a single E protein (HEB) is a possibility. This led us to study the brains of HEB and E2A knockout mice, which manifest no gross neuroanatomical, cellular, or behavioral deficits. These findings, together with homology in the primary peptide sequence of E proteins, suggest functional compensation among E proteins during development of the nervous system.

Publication types

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

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / deficiency
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Basic Helix-Loop-Helix Transcription Factors / physiology*
  • Brain / growth & development*
  • Carcinoma
  • Cell Differentiation / physiology
  • Cell Line, Tumor
  • Electrophoretic Mobility Shift Assay / methods
  • Gene Dosage
  • Immunoprecipitation
  • Mice
  • Mice, Knockout
  • Nerve Tissue Proteins / metabolism
  • Neuropeptides / metabolism*
  • Protein Binding
  • Transfection


  • Basic Helix-Loop-Helix Transcription Factors
  • Nerve Tissue Proteins
  • Neurod2 protein, mouse
  • Neuropeptides
  • Tcf12 protein, mouse
  • Tcf3 protein, mouse