Photic regulation of arylalkylamine N-acetyltransferase binding to 14-3-3 proteins in retinal photoreceptor cells. J Neurosci 2006 Sep 06;26(36):9153-61
Date
09/08/2006Pubmed ID
16957072Pubmed Central ID
PMC6674502DOI
10.1523/JNEUROSCI.1384-06.2006Scopus ID
2-s2.0-33748477917 (requires institutional sign-in at Scopus site) 42 CitationsAbstract
14-3-3 proteins are a ubiquitous, highly conserved family of chaperone proteins involved in signal transduction, regulation of cell cycle, intracellular trafficking/targeting, cytoskeletal structure, and transcription. Although 14-3-3 proteins are among the most abundant proteins in the CNS, very little is known about their functional roles in the vertebrate retina. In the present study, we demonstrated that photoreceptors express 14-3-3 protein(s) and identified a 14-3-3 binding partner in photoreceptor cells, the melatonin-synthesizing enzyme arylalkylamine N-acetyltransferase (AANAT). Importantly, our data demonstrate that the binding of 14-3-3 to AANAT is regulated by light, with dramatic functional consequences. During the night in darkness, retinal AANAT is phosphorylated and forms a complex with 14-3-3 proteins with an apparent molecular weight of approximately 90 kDa. Phosphorylation of AANAT facilitates the binding of enzyme to 14-3-3 proteins. Within the complex, AANAT is catalytically activated and protected from dephosphorylation and degradation. Light disrupts the AANAT/14-3-3 complex, leading to catalytic inactivation, dephosphorylation, and proteolytic degradation of the enzyme. In the presence of the proteasome inhibitor, lactacystin, light results in the formation of a high molecular weight complex (>150 kDa), which may represent an intermediate in the AANAT degradation process. These findings provide new insight into the roles of 14-3-3 proteins in photoreceptor cells and to the mechanisms controlling melatonin synthesis in the vertebrate retina.
Author List
Pozdeyev N, Taylor C, Haque R, Chaurasia SS, Visser A, Thazyeen A, Du Y, Fu H, Weller J, Klein DC, Iuvone PMAuthor
Shyam S. Chaurasia PhD Associate Professor in the Ophthalmology and Visual Sciences department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
14-3-3 ProteinsAnimals
Arylalkylamine N-Acetyltransferase
Cells, Cultured
Chickens
Enzyme Activation
Light
Male
Melatonin
Phosphorylation
Photic Stimulation
Photoreceptor Cells, Vertebrate
Protein Binding
Signal Transduction
