Biology:TPH2

Generic protein structure example

Tryptophan hydroxylase 2 (TPH2) is an isozyme of tryptophan hydroxylase found in vertebrates. In humans, TPH2 is primarily expressed in the serotonergic neurons of the brain, with the highest expression in the raphe nucleus of the midbrain. Until the discovery of TPH2 in 2003, serotonin levels in the central nervous system were believed to be regulated by serotonin synthesis in peripheral tissues, in which tryptophan hydroxylase is the dominant form.

Function

Tryptophan hydroxylase (TPH; EC 1.14.16.4) is the rate-limiting enzyme in the synthesis of serotonin (5-hydroxytryptamine, or 5HT). 5HT is causally involved in numerous central nervous activities, and it has several functions in peripheral tissues, including the maintenance of vascular tone and gut motility.[supplied by OMIM]

See also

• Tryptophan hydroxylase
• TPH1

Further reading

• "Synthesis of serotonin by a second tryptophan hydroxylase isoform". Science 299 (5603): 76. Jan 2003. doi:10.1126/science.1078197. PMID 12511643. 
• "A unique central tryptophan hydroxylase isoform". Biochemical Pharmacology 66 (9): 1673–80. Nov 2003. doi:10.1016/S0006-2952(03)00556-2. PMID 14563478. 
• "SNP and haplotype analysis of a novel tryptophan hydroxylase isoform (TPH2) gene provide evidence for association with major depression". Molecular Psychiatry 9 (11): 1030–6. Nov 2004. doi:10.1038/sj.mp.4001525. PMID 15124006. 
• "Identification of genetic variants in the neuronal form of tryptophan hydroxylase (TPH2)". Psychiatric Genetics 14 (2): 69–72. Jun 2004. doi:10.1097/01.ypg.0000107929.32051.58. PMID 15167691. 
• "Analysis of the novel TPH2 gene in bipolar disorder and suicidality". Molecular Psychiatry 9 (10): 896–7. Oct 2004. doi:10.1038/sj.mp.4001531. PMID 15197398. 
• "Support for the involvement of TPH2 gene in affective disorders". Molecular Psychiatry 9 (11): 980–1. Nov 2004. doi:10.1038/sj.mp.4001557. PMID 15263906. 
• "Single nucleotide polymorphism and haplotype analysis of a novel tryptophan hydroxylase isoform (TPH2) gene in suicide victims". Biological Psychiatry 56 (8): 581–6. Oct 2004. doi:10.1016/j.biopsych.2004.07.015. PMID 15476687. 
• "Loss-of-function mutation in tryptophan hydroxylase-2 identified in unipolar major depression". Neuron 45 (1): 11–6. Jan 2005. doi:10.1016/j.neuron.2004.12.014. PMID 15629698. 
• "Possible association between autism and variants in the brain-expressed tryptophan hydroxylase gene (TPH2)". American Journal of Medical Genetics Part B 135B (1): 42–6. May 2005. doi:10.1002/ajmg.b.30168. PMID 15768392. 
• "Tryptophan hydroxylase 2 (TPH2) gene variants associated with ADHD". Molecular Psychiatry 10 (10): 944–9. Oct 2005. doi:10.1038/sj.mp.4001698. PMID 15940290. 
• "Postmortem parietal cortex TPH2 expression is not altered in schizophrenic, unipolar-depressed, and bipolar patients vs control subjects". Journal of Molecular Neuroscience 26 (1): 33–7. 2005. doi:10.1385/JMN:26:1:033. PMID 15968084. 
• "A regulatory variant of the human tryptophan hydroxylase-2 gene biases amygdala reactivity". Molecular Psychiatry 10 (9): 884–8, 805. Sep 2005. doi:10.1038/sj.mp.4001716. PMID 16044172. 
• "Transmission disequilibrium of polymorphic variants in the tryptophan hydroxylase-2 gene in attention-deficit/hyperactivity disorder". Molecular Psychiatry 10 (12): 1126–32. Dec 2005. doi:10.1038/sj.mp.4001734. PMID 16116490. 
• "Amygdala responsiveness is modulated by tryptophan hydroxylase-2 gene variation". Journal of Neural Transmission 112 (11): 1479–85. Nov 2005. doi:10.1007/s00702-005-0391-4. PMID 16245070. 
• "The novel brain-specific tryptophan hydroxylase-2 gene in panic disorder". Journal of Psychopharmacology 20 (4): 547–52. Jul 2006. doi:10.1177/0269881106059704. PMID 16401665. 
• "The interaction between TPH2 promoter haplotypes and clinical-demographic risk factors in suicide victims with major psychoses". Genes, Brain, and Behavior 5 (1): 107–10. Feb 2006. doi:10.1111/j.1601-183X.2005.00182.x. PMID 16436194. 
• "No human tryptophan hydroxylase-2 gene R441H mutation in a large cohort of psychiatric patients and control subjects". Biological Psychiatry 60 (2): 202–3. Jul 2006. doi:10.1016/j.biopsych.2005.12.014. PMID 16581035. http://www.hal.inserm.fr/inserm-00124742/document. 
• "Functional domains of human tryptophan hydroxylase 2 (hTPH2)". The Journal of Biological Chemistry 281 (38): 28105–12. Sep 2006. doi:10.1074/jbc.M602817200. PMID 16864580.