1. Pet-1 Controls Tetrahydrobiopterin Pathway and Slc22a3 Transporter Genes in Serotonin Neurons
- Author
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Steven C. Wyler, Lauren J Donovan, Mia Yeager, and Evan S. Deneris
- Subjects
Dorsal Raphe Nucleus ,Organic Cation Transport Proteins ,Physiology ,Cognitive Neuroscience ,Mice, Transgenic ,Tryptophan Hydroxylase ,Biology ,Real-Time Polymerase Chain Reaction ,Biochemistry ,Article ,SLC22A3 ,Reuptake ,Bacterial Proteins ,Gene expression ,medicine ,Transcriptional regulation ,Animals ,GTP Cyclohydrolase ,Transcription factor ,Mice, Knockout ,Serotonin Plasma Membrane Transport Proteins ,TPH2 ,Transporter ,Cell Biology ,General Medicine ,Tetrahydrobiopterin ,Biopterin ,Rhombencephalon ,Luminescent Proteins ,Receptor, Serotonin, 5-HT1A ,biology.protein ,Carrier Proteins ,Serotonergic Neurons ,Signal Transduction ,Transcription Factors ,medicine.drug - Abstract
Coordinated serotonin (5-HT) synthesis and reuptake depends on coexpression of Tph2, Aadc (Ddc), and Sert (Slc6a4) in brain 5-HT neurons. However, other gene products play critical roles in brain 5-HT synthesis and transport. For example, 5-HT synthesis depends on coexpression of genes encoding the enzymatic machinery necessary for the production and regeneration of tetrahydrobiopterin (BH4). In addition, the organic cation transporter 3 (Oct3, Slc22a3) functions as a low affinity, high capacity 5-HT reuptake protein in 5-HT neurons. The regulatory strategies controlling BH4 and Oct3 gene expression in 5-HT neurons have not been investigated. Our previous studies showed that Pet-1 is a critical transcription factor in a regulatory program that controls coexpression of Tph2, Aadc, and Sert in 5-HT neurons. Here, we investigate whether a common regulatory program determines global 5-HT synthesis and reuptake through coordinate transcriptional control. We show with comparative microarray profiling of flow sorted YFP(+) Pet-1(-/-) and wild type 5-HT neurons that Pet-1 regulates BH4 pathway genes, Gch1, Gchfr, and Qdpr. Thus, Pet-1 coordinates expression of all rate-limiting enzymatic (Tph2, Gch1) and post-translational regulatory (Gchfr) steps that determine the level of mammalian brain 5-HT synthesis. Moreover, Pet-1 globally controls acquisition of 5-HT reuptake in dorsal raphe 5-HT neurons by coordinating expression of Slc6a4 and Slc22a3. In situ hybridizations revealed that virtually all 5-HT neurons in the dorsal raphe depend on Pet-1 for Slc22a3 expression; similar results were obtained for Htr1a. Therefore, few if any 5-HT neurons in the dorsal raphe are resistant to loss of Pet-1 for their full neuron-type identity.
- Published
- 2015