Identification of putative amine biosynthetic enzymes in the nervous system of the crab, Cancer borealis

Abstract

Amines function as neuromodulators throughout the animal kingdom. In decapod crustaceans, the amines serving neuromodulatory roles include dopamine, octopamine, serotonin and histamine. While much work has focused on examining the physiological effects of amines on decapod nervous systems, the identity of the native enzymes involved in their biosynthesis remains largely unknown. In an attempt to help fill this void, a transcriptome generated from multiple portions of the crab, Cancer borealis, nervous system, a species that has long served as a model species for investigating the neuromodulatory control of rhythmically active neural networks, was used to identify putative amine biosynthetic enzyme-encoding transcripts, and by proxy, proteins. Transcripts encoding full complements of the enzymes involved in the production of dopamine, octopamine, serotonin, and histamine were deduced from the C. borealis assembly, i.e., tryptophan–phenylalanine hydroxylase, tyrosine hydroxylase, DOPA decarboxylase, tyrosine decarboxylase, tyramine β-hydroxylase, tryptophan hydroxylase, and histidine decarboxylase. All proteins deduced from the C. borealis transcripts appear to be full-length sequences, with reciprocal BLAST and structural domain analyses supporting the protein family annotations ascribed to them. These data provide the first descriptions of the native amine biosynthetic enzymes of C. borealis, and as such, serve as a resource for initiating gene-based studies of aminergic control of physiology and behavior at the level of biosynthesis in this important biomedical model.