Serotonin N-acetyltransferase mRNA levels in photoreceptor-enriched chicken retinal cell cultures: elevation by cyclic AMP.
Serotonin N-acetyltransferase (AA-NAT; arylalkylamine N-acetyltransferase; EC 2.3.1.87) is a key regulatory enzyme in the biosynthesis of melatonin. Previous studies have shown that the activity of this enzyme in the chicken retina is regulated by a cyclic AMP-dependent mechanism. In the present report, we investigated whether cyclic AMP can regulate the levels of AA-NAT mRNA in photoreceptor-enriched chick retinal cell cultures. AA-NAT mRNA levels were elevated by acute treatment with cyclic AMP protagonists, including forskolin; this response was blocked by H-89, a selective inhibitor of cyclic AMP-dependent protein kinase. Forskolin did not alter the rate of disappearance of AA-NAT mRNA in actinomycin D-treated cells, suggesting that cyclic AMP enhances transcription of the AA-NAT gene. Forskolin-induced elevation of AA-NAT mRNA levels was enhanced by cycloheximide, which decreased the degradation of the transcript in cells treated with actinomycin D. These studies indicate that the abundance of AA-NAT mRNA is regulated in part through a cyclic AMP-dependent mechanism.
Grève
P
P
Emory University School of Medicine, Atlanta, Georgia 30322-3090, USA.
Alonso-Gómez
A
A
Bernard
M
M
Ma
M
M
Haque
R
R
Klein
D C
DC
Iuvone
P M
PM
D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000235:genetics*; D002642:Chick Embryo; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D010786:Photoreceptor Cells / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism*; D012160:Retina / Q000187:drug effects / Q000201:enzymology*; D013449:Sulfonamides
D004791:Enzyme Inhibitors; D007546:Isoquinolines; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D013449:Sulfonamides; D003609:Dactinomycin; D005576:Colforsin; D003513:Cycloheximide; D000242:Cyclic AMP; D001191:Arylamine N-Acetyltransferase; D017868:Cyclic AMP-Dependent Protein Kinases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide