Regulation of striatal D1A dopamine receptor gene transcription by Brn-4.
Brn-4 is a member of the POU transcription factor family and is expressed in the central nervous system. In this study, we addressed whether Brn-4 regulates expression of the D1A dopamine receptor gene. We found a functional Brn-4 responsive element in the intron of this gene by means of cotransfection chloramphenical acetyltransferase assays. This region contains two consensus sequences for binding of POU factors. Gel mobility-shift assays using glutathione S-transferase-Brn-4 fusion protein indicated that Brn-4 binds to these sequences. Both these sites are essential for transactivation by Brn-4 because deletion of either significantly reduced this enhancer activity. In situ hybridization revealed colocalization of Brn-4 and D1A mRNAs at the level of a single neuron in the rat striatum where this dopamine receptor is most abundantly expressed. Gel mobility-supershift assay using rat striatal nuclear extract and Brn-4 antibody confirmed the presence of Brn-4 in this brain region and its ability to bind to its consensus sequences in the D1A gene. These data suggest a functional role for Brn-4 in the expression of the D1A dopamine receptor gene both in vitro and in vivo.
Okazawa
H
H
Department of Neurology, Faculty of Medicine, University of Tokyo, Japan.
Imafuku
I
I
Minowa
M T
MT
Kanazawa
I
I
Hamada
H
H
Mouradian
M M
MM
D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D003587:Cytomegalovirus; D017931:DNA Primers; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D005822:Genetic Vectors; D005982:Glutathione Transferase; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D051381:Rats; D017447:Receptors, Dopamine D1 / Q000096:biosynthesis*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014157:Transcription Factors / Q000096:biosynthesis / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection / Q000379:methods
D017931:DNA Primers; D015345:Oligonucleotide Probes; D017447:Receptors, Dopamine D1; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C098593:dopamine D1A receptor; D015500:Chloramphenicol O-Acetyltransferase; D005982:Glutathione Transferase