Transcription and epigenetic profile of the promoter, first exon and first intron of the human tyrosine hydroxylase gene

Abstract

The transcriptional and chromatin profile of the promoter, first exon and first intron of the human TH gene were analyzed in human neuroblastoma BE(2)-C-16 and human renal carcinoma 293FT cell lines. The latter is a cell culture system that is not permissive for TH gene expression, whereas the former has a 50% cell fraction that tests positive for TH. The engineering of a 6.3 kb recombinant human TH promoter revealed the presence of repressors of transcription between positions (−6,244/ −194). The addition of a 1.2 kb fragment of the first intron of the human TH gene (+730/+1,653) enhanced transcriptional activity of the recombinant promoter. However, both constructs were not specific for TH-positive BE(2)-C-16 cells. Chromatin immunoprecipitation (Chip) analysis was carried out on BE(2)-C-16 and 293FT cells to probe sequences of promoter, first exon and first intron of the human TH gene from position (−448/+1,204). The presence of nucleosomes was observed approximately from position (−20/+473) in both cell lines. Chip analysis was then conducted to determine the acetylation of various lysine residues of H3 and H4 in both cell lines. All analyzed lysine residues of H3 and H4 were acetylated in BE(2)-C-16 cells, whereas 293FT cells tested positive for acetylation only in the external lysine residues of the histone tail. Our data are compatible with an active TH gene expression in a 50% cell fraction of BE(2)-C-16 cells. Further analysis of epigenetic programming might lead to the identification of the factors that determine TH gene expression specifically in dopaminergic neurons.The elucidation of the mechanism of human tyrosine hydroxylase (TH) gene regulation is one of the key issues in the field of neurology. The function of TH consists of catalyzing tyrosine hydroxylation in the synthesis of L-dopa (Nagatsu et al., 1964), which is the rate-limiting step in the generation of catecholamine neurotransmitters of the central and peripheral nervous systems (Zigmond et al., 1989). There are a number of important reasons to continue to explore the complex mechanism of TH gene regulation. For instance, aberrant TH gene expression is observed in alcoholism and in psychiatric illnesses, such as schizophrenia and bipolar disorder (Ishiguro et al., 1998). In addition, the degeneration of TH-positive dopaminergic neurons of the substantia nigra is associated with Parkinson's disease (Moore, 2003).Many studies have been conducted to characterize the factors that come into play in TH gene regulation. These studies focused mainly on the human (Kessler et al., 2003;Romano et al., 2005;Jin et al., 2006), mouse (Kim et al., 2003a) and rat models (Gandelman et al., 1990 et al., 2003b). In a previous report, a 13 kb DNA fragment containing the human TH promoter was isolated from a genomic DNA library, sequenced and utilized to generate both a transgenic animal model (Kessler et al., 2003) and a variety of recombinant minimal TH promoters assembled in a self-inactivating lentiviral vector system (Romano et al., 2005). All...

Cooperation of Nuclear Fibroblast Growth Factor Receptor 1 and Nurr1 Offers New Interactive Mechanism in Postmitotic Development of Mesencephalic Dopaminergic Neurons

“…Previous reports also suggest that first intron of the TH gene is critical for differential gene regulation among species (48) and can bind Nurr1 (49). In our study, we analyzed Nurr1 and FGFR1 binding to NBRE-like sequence in the TH gene intron-1 (NBS 1; Fig.…”

Epigenetic, transcriptional and posttranscriptional regulation of the tyrosine hydroxylase gene

“…Substitution of this area with the reporter gene in one of the TH loci resulted in a disturbed expression pattern of the recombined gene in transgenic mice (Kelly et al, 2006). The high acetylation level of histone lysine residues and the presence of sites hypersensitive to DNase I implies an open chromatin structure in this area and the presence of binding sites for transcriptional factors (Kelly et al, 2006; Romano et al, 2007).…”

“…The proven mechanisms of their action, however, include the transcriptional activation of promoter elements (BRE and CRE) (Patel et al, 2005) by phosphorylated CREB-like factors (Shah et al, 2006) and destabilization of TH mRNA by destroying the interactions of proteins with its 3 ′ UTR (Arányi et al, 2007). Only the results of Romano et al (2007) demonstrate a tissue-specific correlation of histone acetylation with TH gene activity. TH + cells contain an increased level of acetylated lysine residues in H3 and H4 histones in the chromatin covering the −20/+473 region of the TH gene.…”

Expression Levels of the Tyrosine Hydroxylase Gene and Histone Modifications Around its Promoter in the Locus Coeruleus and Ventral Tegmental Area of Rats during Forced Abstinence from Morphine

“…To date, the role of histone acetylation in the TH gene regulation in morphine addiction has not been investigated. However, tissue-specific correlation of histone acetylation with human TH gene activity is verified [53]. Further, histone H3 phospho-acetylation at the promoter sequences of TH in the striatum of cocaine treated mice was shown to be linked to the activation of dopamine receptor D1-signaling [54].…”