Identification of a New Enhancer in the Promoter Region of Human TR3 Orphan Receptor Gene: A MEMBER OF STEROID RECEPTOR SUPERFAMILY

Hiroji Uemura,Atsushi Mizokami,Chawnshang Chang

doi:10.1074/jbc.270.10.5427

Hiroji Uemura, Atsushi Mizokami + Show 1 more

Open Access

https://doi.org/10.1074/jbc.270.10.5427

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Abstract

Human TR3 orphan receptor is a member of the steroid/thyroid hormone receptor superfamily and is the human homologue of the proteins encoded by the rat NGFI-B and mouse nur77 genes. These genes are induced rapidly by androgens/growth factors and may have functions related to cell proliferation, differentiation, and apoptosis. To investigate the TR3 orphan receptor gene transcriptional regulation, a 2.3-kilobase genomic DNA fragment containing the TR3 orphan receptor gene promoter region was isolated, sequenced, and characterized. Sequence homology search within this promoter region revealed some potential cis-acting elements such as cAMP response element, interleukin-6 response element, estrogen response element, and GC box. Deletion analysis and chloramphenicol acetyltransferase assay also showed a novel cis-acting element of TR3 orphan receptor gene (NCAE-TR3), 200-181 base pairs upstream of the transcriptional start site. Gel retardation assay further demonstrated that some nuclear factors can bind to this NCAE-TR3. Together, our data suggest that NCAE-TR3 could be a new enhancer element associated with the transcription of an early response gene for mitogenesis and apoptosis.

Highlights

Human TR3 orphan receptor is a member of the steroid/thyroid hormone receptor superfamily and is the human homologue of the proteins encoded by the rat NGFI-B and mouse nur77 genes
This receptor is a human homologue of the protein encoded by mouse nur77 [9,10], NIO gene [11], and rat NGFI-B gene [12], which are thought to be the early response genes immediately induced by androgens and several growth factors
Construction of Human TR3 Orphan Receptor Gene Promoter CAT Plasmids-A series of deletion mutants of human TR3 orphan receptor gene promoter CAT plasmids (p-1830TR3CAT, p-1500TR3CAT, p-1180TR3CAT, p-940TR3CAT, p-730TR3CAT) were created using Exonuclease III (New England Biolabs), p-427TR3CAT and p-121TR3CAT were constructed by deletion of 1700- and 2000-bp SmaI-SmaI fragments of p-2149TR3CAT. p-314TR3CAT was constructed by deletion of a 181O-bp XbaI-NarI fragment of p-2149TR3CAT

Summary

Introduction

Human TR3 orphan receptor is a member of the steroid/thyroid hormone receptor superfamily and is the human homologue of the proteins encoded by the rat NGFI-B and mouse nur genes These genes are induced rapidly by androgens/growth factors and may have functions related to cell proliferation, differentiation, and apoptosis. The cDNA of human TR3 orphan receptor was isolated during the screening of human testis and prostate cDNA libraries for androgen receptor (AR)l cDNAs using an oligonucleotide probe homologous to the highly conserved part of the DNA binding domain of glucocorticoid receptor [6,7,8] This receptor is a human homologue of the protein encoded by mouse nur77 [9,10], NIO gene [11], and rat NGFI-B gene [12], which are thought to be the early response genes immediately induced by androgens and several growth factors. Receptor mRNA in human prostate LNCaP cell can be rapidly and biphasically induced by the addition of androgens or growth factors [13]

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