Differential DNA binding activities of the transcription factors AP-1 and Oct-1 during light-induced apoptosis of photoreceptors

Vision Res. 1999 Jul;39(15):2511-8. doi: 10.1016/s0042-6989(98)00313-7.


The activity of transcription factors like AP-1 and Oct-1 is critical for the regulation of gene expression. Whereas Oct-1 mainly regulates the expression of housekeeping genes, AP-1 is often involved in cellular responses to external stimuli and plays an essential role in the regulation of light-induced apoptosis of mouse retinal photoreceptors. In this study, we investigated AP-1 and Oct-1 DNA binding activity and AP-1 complex composition in the mouse retina during light-induced photoreceptor apoptosis. AP-1 DNA binding activity was low in dark-adapted animals but was transiently elevated within 12 h after exposure of mice to apoptosis-inducing levels of white fluorescent light. Maximal AP-1 activity was found 6 h after light-exposure. Antibody interference analysis at 6 h after damaging light exposure and under normal light conditions revealed that the major fraction of AP-1 consists of c-Fos/JunD heterodimers in both situations. In contrast to AP-1, Oct-1 DNA binding activity was maximal in dark-adapted animals and was reduced during photoreceptor apoptosis. Transient induction of AP-1 (c-Fos/JunD) and inactivation of Oct-1 may be crucial events for light-mediated apoptosis of retinal photoreceptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / radiation effects*
  • DNA / metabolism*
  • DNA-Binding Proteins / metabolism*
  • Dark Adaptation
  • Gene Expression Regulation
  • Host Cell Factor C1
  • Light
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Octamer Transcription Factor-1
  • Photoreceptor Cells / cytology
  • Photoreceptor Cells / radiation effects*
  • Retina / metabolism
  • Time Factors
  • Transcription Factor AP-1 / metabolism*
  • Transcription Factors / metabolism*


  • DNA-Binding Proteins
  • Hcfc1 protein, mouse
  • Host Cell Factor C1
  • Octamer Transcription Factor-1
  • Pou2f1 protein, mouse
  • Transcription Factor AP-1
  • Transcription Factors
  • DNA