Retinal melatonin production: role of proteasomal proteolysis in circadian and photic control of arylalkylamine N-acetyltransferase.

Abstract

AA-NAT activity measured in tissue homogenates reflects the steady state level of enzyme protein. AA-NAT protein in the retina turns over rapidly, reflecting a balance of de novo synthesis and proteasomal proteolysis. The suppressive effects of light at night are due primarily to enhanced AA-NAT proteolysis.