ZFIN ID: ZDB-PUB-040304-2
Zebrafish serotonin-N-acetyltransferase-2 gene regulation: Pineal-restrictive downstream module (PRDM) contains a functional E-box and three photoreceptor conserved elements
Appelbaum, L., Toyama, R., Dawid, I.B., Klein, D.C., Baler, R., and Gothilf, Y.
Date: 2004
Source: Molecular endocrinology (Baltimore, Md.)   18(5): 1210-1221 (Journal)
Registered Authors: Dawid, Igor B., Gothilf, Yoav, Klein, David C., Toyama, Reiko
Keywords: none
MeSH Terms:
  • Animals
  • Arylalkylamine N-Acetyltransferase/genetics
  • Arylalkylamine N-Acetyltransferase/metabolism*
  • Base Sequence
  • Circadian Rhythm/physiology*
  • Cloning, Molecular
  • Embryo, Nonmammalian/enzymology
  • Melatonin/metabolism*
  • Molecular Sequence Data
  • Photoreceptor Cells/metabolism
  • Pineal Gland/enzymology*
  • Regulatory Sequences, Nucleic Acid/genetics
  • Zebrafish/embryology
  • Zebrafish/genetics*
PubMed: 14988431 Full text @ Mol. Endocrinol.
Pineal function is defined by a set of very narrowly expressed genes that encode proteins required for photoperiodic transduction and rhythmic melatonin secretion. One of these proteins is serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AANAT), which controls the daily rhythm in melatonin production. Here, pineal-specific expression of the zebrafish aanat-2 (zfaanat-2) was studied using in vivo transient expression analyses of promoter-reporter constructs; this revealed that specificity is determined by two regions located 12 kb away from each other. One is the 5'-flanking region and the other is a 257 bp sequence, located 6 kb downstream of the transcribed region. This 3' sequence, designated pineal-restrictive downstream module (PRDM), has a dual function: enhancement of pineal expression and inhibition of extra-pineal expression. The former is an autonomic property of PRDM while the later function requires interaction with the upstream regulatory region of zfaanat-2. Functional analyses of the PRDM sequence revealed that three photoreceptor conserved elements (PCE; TAATC) and a single perfect E-box (CACGTG) are crucial for the dual function of PRDM. These results indicate that pineal-specificity of zfaanat-2 is determined by the dual functionality of the PRDM and the interaction between upstream regulatory region and downstream PCEs and E-box element.