Subfunctionalization of arylalkylamine N-acetyltransferases in the sea bass Dicentrarchus labrax: two-ones for one two.
Melatonin is an important component of the vertebrates circadian system, synthetized from serotonin by the successive action of the arylalkylamine N-acetyltransferase (Aanat: serotonin→N-acetylserotonin) and acetylserotonin-O-methyltransferase (Asmt: N-acetylserotonin→melatonin). Aanat is responsible for the daily rhythm in melatonin production. Teleost fish are unique because they express two Aanat genes, aanat1 and aanat2, mainly expressed in the retina and pineal gland, respectively. In silico analysis indicated that the teleost-specific whole-genome duplication generated Aanat1 duplicates (aanat1a and aanat1b); some fish express both of them, while others express either one of the isoforms. Here, we bring the first information on the structure, function, and distribution of Aanat1a and Aanat1b in a teleost, the sea bass Dicentrarchus labrax. Aanat1a and Aanat1b displayed a wide and distinct distribution in the nervous system and peripheral tissues, while Aanat2 appeared as a pineal enzyme. Co-expression of Aanats with asmt was found in the pineal gland and the three retinal nuclear layers. Enzyme kinetics indicated subtle differences in the affinity and catalytic efficiency of Aanat1a and Aanat1b for indolethylamines and phenylethylamines, respectively. Our data are consistent with the idea that Aanat2 is a pineal enzyme involved in melatonin production, while Aanat1 enzymes have a broader range of functions including melatonin synthesis in the retina, and catabolism of serotonin and dopamine in the retina and other tissues. The data are discussed in light of the recently uncovered roles of N-acetylserotonin and N-acetyldopamine as antioxidants, neuroprotectants, and modulators of cell proliferation and enzyme activities.
UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Sorbonne Universités, Banyuls/Mer, France.
Charles-Hubert
CH
Paulin
UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Sorbonne Universités, Banyuls/Mer, France.
Damien
D
Cazaméa-Catalan
Department of Neurobiology, George S. Wise Faculty of Life Sciences and Sagol School of Neurosciences, University of Tel Aviv, Tel Aviv, Israel.
Bina
B
Zilberman-Peled
Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, Cádiz, Spain.
Patricia
P
Herrera-Perez
UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Sorbonne Universités, Banyuls/Mer, France.
Sandrine
S
Sauzet
UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Sorbonne Universités, Banyuls/Mer, France.
Elodie
E
Magnanou
UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Sorbonne Universités, Banyuls/Mer, France.
Michael
M
Fuentès
Department of Neurobiology, George S. Wise Faculty of Life Sciences and Sagol School of Neurosciences, University of Tel Aviv, Tel Aviv, Israel.
Yoav
Y
Gothilf
Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, Cádiz, Spain.
Jose Antonio
JA
Muñoz-Cueto
UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Sorbonne Universités, Banyuls/Mer, France.
Jack
J
Falcón
UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, Sorbonne Universités, Banyuls/Mer, France.
Laurence
L
Besseau
D000818:Animals; D047068:Arylalkylamine N-Acetyltransferase / Q000378:metabolism*; D001492:Bass / Q000378:metabolism*; D004298:Dopamine / Q000031:analogs & derivatives / Q000378:metabolism; D012701:Serotonin / Q000031:analogs & derivatives / Q000378:metabolism
C006374:N-acetyldopamine; D012701:Serotonin; D047068:Arylalkylamine N-Acetyltransferase; C006389:N-acetylserotonin; D004298:Dopamine
arylalkylamine N-acetyltransferase; dopamine; melatonin; pineal organ; retina; serotonin; teleost Fish