Photoreceptor-specific expression, light-dependent localization, and transcriptional targets of the zinc-finger protein Yin Yang 1 in the chicken retina

J Neurochem. 2008 May;105(3):595-604. doi: 10.1111/j.1471-4159.2007.05150.x. Epub 2007 Nov 28.

Abstract

The zinc-finger transcription factor Yin Yang 1 (YY1) is a multifunctional protein that plays a critical role in embryonic development. Although it has been shown to play a role in eye development, its expression in the retina was not previously described. Here, we investigated YY1 expression in chicken tissues and we identified the neural retina as one of the tissues with highest YY1 protein levels. Immunohistochemical detection of YY1 in the retina revealed a clear-cut photoreceptor specificity and day/night differences in the cytoplasmic localization of the protein. YY1 was also present at high concentration in the nuclei of some photoreceptors. Gel-shift assays indicated YY1 bound to regulatory regions of several genes specifically expressed in photoreceptors. One of these genes, hydroxyindole-O-methyltransferase (EC 2.1.1.4), encodes the last enzyme of the melatonin synthesis pathway. Although over-expression of chicken YY1 was not sufficient to activate the chicken hydroxyindole-O-methyltransferase promoter in HEK293 cells, the YY1-binding site contained in this promoter was clearly required for full transcriptional activity in chicken embryonic retinal cells. These results suggest a role of YY1 in regulating the melatoninergic function of retinal photoreceptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylserotonin O-Methyltransferase / metabolism
  • Animals
  • Binding Sites / genetics
  • Cell Line
  • Cell Nucleus / metabolism
  • Chick Embryo
  • Chickens
  • Circadian Rhythm / genetics
  • Cytoplasm / metabolism
  • Gene Expression Regulation, Developmental / genetics
  • Humans
  • Immunohistochemistry
  • Light Signal Transduction / genetics*
  • Melatonin / biosynthesis*
  • Photoreceptor Cells, Vertebrate / cytology
  • Photoreceptor Cells, Vertebrate / metabolism*
  • Photoreceptor Cells, Vertebrate / radiation effects
  • Promoter Regions, Genetic / genetics
  • Retina / cytology
  • Retina / embryology
  • Retina / metabolism*
  • Transcriptional Activation / genetics*
  • YY1 Transcription Factor / genetics
  • YY1 Transcription Factor / metabolism*
  • YY1 Transcription Factor / radiation effects
  • Zinc Fingers / genetics

Substances

  • YY1 Transcription Factor
  • Acetylserotonin O-Methyltransferase
  • Melatonin