Identification of specific histidine residues and the carboxyl terminus are essential for serotonin N-acetyltransferase enzymatic activity.

Melatonin is synthesized in pinealocytes of the pineal gland and in photoreceptors of the retina. Synthesis rate from serotonin to melatonin is controlled by the rapid and dramatic enzymatic increase in darkness of serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AA-NAT, EC 2.3.

Biochemical characterization of recombinant serotonin N-acetyltransferase.

Pineal and retinal melatonin synthesis is controlled by the enzymatic activity of arylalkylamine N-acetyltransferase (AA-NAT, EC 2.3.1.

Bovine arylalkylamine N-acetyltransferase activity correlated with mRNA expression in pineal and retina.

Arylalkylamine N-acetyltransferase (AA-NAT, E. C. 2.

PhLPs and PhLOPs in the phosducin family of G beta gamma binding proteins.

In this study, we identify new isoforms of the retinal phosducin and investigate the expression of the phosducin family, showing that an isoform, PhLP1, has sequence homology with Phd and Gbeta gamma binding capability, whereas two isoforms (phosducin-like orphan proteins, PhLOPs) share sequence homology with Phd but fail to bind Gbeta gamma. Original identification of PhLP1 and the PhLOPs was from a human retina cDNA library, using a PCR product for library hybridization screening that contained a predicted functional epitope domain. The screen identified Phd and three related, but distinct, recombinants (PhLP1, PhLOP1, and PhLOP2).