Characterization of the chicken serotonin N-acetyltransferase gene. Activation via clock gene heterodimer/E box interaction

J Biol Chem. 2000 Oct 20;275(42):32991-8. doi: 10.1074/jbc.M005671200.


The abundance of serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AANAT) mRNA in the chicken pineal gland exhibits a circadian rhythm, which is translated into a circadian rhythm in melatonin production. Here we have started to elucidate the molecular basis of the circadian rhythm in chicken AANAT (cAANAT). The 5'-flanking region of the cAANAT gene was isolated and found to contain an E box DNA element that confers strong luciferase reporter activity. In transfection experiments using chicken pineal cells, an E box mutation dramatically decreased reporter activity. Northern blot analysis indicated that several putative clock genes (bmal1, Clock, and MOP4) are co-expressed in the chicken pineal gland. bmal1 mRNA is expressed in a rhythmic manner in the chicken pineal gland, with peak levels at early subjective night, coincident with the increase in cAANAT expression. Co-transfection experiments in COS cells demonstrated that chicken BMAL1/CLOCK and human BMAL1/MOP4 heterodimers bound the AANAT E box element and enhanced transcription. These observations suggest that binding of clock gene heterodimers to the cAANAT E box is a critical element in the expression of the cAANAT gene in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ARNTL Transcription Factors
  • Animals
  • Arylamine N-Acetyltransferase / genetics*
  • Base Sequence
  • Basic Helix-Loop-Helix Transcription Factors
  • CLOCK Proteins
  • COS Cells
  • Chickens / genetics*
  • Circadian Rhythm
  • Dimerization
  • Gene Expression Regulation, Enzymologic*
  • Gene Library
  • Helix-Loop-Helix Motifs
  • Humans
  • Molecular Sequence Data
  • Pineal Gland / metabolism*
  • Promoter Regions, Genetic*
  • Restriction Mapping
  • Retina / physiology
  • Sequence Deletion
  • Trans-Activators / chemistry
  • Trans-Activators / genetics*
  • Trans-Activators / metabolism*
  • Transcription Factors / genetics
  • Transcription, Genetic
  • Transcriptional Activation
  • Transfection


  • ARNTL Transcription Factors
  • ARNTL protein, human
  • Basic Helix-Loop-Helix Transcription Factors
  • Trans-Activators
  • Transcription Factors
  • CLOCK Proteins
  • CLOCK protein, human
  • Arylamine N-Acetyltransferase

Associated data

  • GENBANK/AF144425
  • GENBANK/AF193070
  • GENBANK/AF193071
  • GENBANK/AF193072
  • GENBANK/AF205219