"A circadian NeuroD1 protein as a potential Aanat gene regulator in the adult rat pineal gland"

A.CASTRO; S. BENITEZ; M. FITT; V. ORTIZ MALDONADO; L. SAVASTANO; E. MUÑOZ

Huerta Grande

Congreso; XXVI Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias,; 2011

Sociedad Argentina de Investigación en Neurociencias

"A circadian NeuroD1 protein as a potential Aanat gene regulator in the adult rat pineal gland"Analía Castro, Sergio Benítez, Marcos Fitt, Valentin Ortiz Maldonado, Luis Savastano, Estela MuñozLaboratorio de Neurobiología, Sección de Cronobiología, IHEM-CONICET, FCM-UNCuyo, Mendoza, Argentina. ANPCyT.acastro@fcm.uncu.edu.arNeuroD1 is a transcription factor responsible for the establishment and maintenance of endocrine phenotypes. In the pineal gland, the Aanat gene encodes a key enzyme in melatonin synthesis, the arylalkylamine N-acetyltransferase. E-Box motifs identified in the Aanat gene promoter have been associated with its highly tissue-specific expression. In this work, we characterized NeuroD1 protein expression in adult rat pineal glands via IHC and WB. We also determined, via EMSA, whether an E-Box motif located upstream of the CRE-inverted CCAAT cassette in the Aanat promoter might recruit NeuroD1. NeuroD1-immunoreactivity was observed in pinealocytes and in a subpopulation of vimentin-positive astrocytes. Whereas at ZT14 NeuroD1 was mainly nuclear, at ZT6 there was a weaker signal in the cytoplasm. After SCGx, a heterogeneous pattern of subcellular NeuroD1-immunostaining was observed among pinealocytes at ZT14. These data were confirmed by WB. Aanat E-Box-containing probe was able to bind proteins from pineal nuclear extracts; NeuroD1 may form part of these complexes, according to supershift assays with an anti-NeuroD1 antibody. These results suggest that NeuroD1 protein dynamics are under circadian control and that NeuroD1 modulates Aanat gene expression in the adult rat pineal gland.