title: Retina-specific nuclear receptor: A potential regulator of cellular retinaldehyde-binding protein expressed in retinal pigment epithelium and Müller glial cells.
abstract: In an effort to identify nuclear receptors important in retinal disease, we screened a retina cDNA library for nuclear receptors. Here we describe the identification of a retina-specific nuclear receptor (RNR) from both human and mouse. Human RNR is a splice variant of the recently published photoreceptor cell-specific nuclear receptor [Kobayashi, M., Takezawa, S., Hara, K., Yu, R. T., Umesono, Y., Agata, K., Taniwaki, M., Yasuda, K. & Umesono, K. (1999) Proc. Natl. Acad. Sci. USA 96, 4814-4819] whereas the mouse RNR is a mouse ortholog. Northern blot and reverse transcription-PCR analyses of human mRNA samples demonstrate that RNR is expressed exclusively in the retina, with transcripts of approximately 7.5 kb, approximately 3.0 kb, and approximately 2.3 kb by Northern blot analysis. In situ hybridization with multiple probes on both primate and mouse eye sections demonstrates that RNR is expressed in the retinal pigment epithelium and in Müller glial cells. By using the Gal4 chimeric receptor/reporter cotransfection system, the ligand binding domain of RNR was found to repress transcriptional activity in the absence of exogenous ligand. Gel mobility shift assays revealed that RNR can interact with the promoter of the cellular retinaldehyde binding protein gene in the presence of retinoic acid receptor (RAR) and/or retinoid X receptor (RXR). These data raise the possibility that RNR acts to regulate the visual cycle through its interaction with cellular retinaldehyde binding protein and therefore may be a target for retinal diseases such as retinitis pigmentosa and age-related macular degeneration.
authors.affiliation: Department of Human Genetics, Merck Research Laboratories, West Point, PA 19486, USA. fang_chen@merck.com
authors.forename: F
authors.initials: F
authors.lastname: Chen
authors.forename: D J
authors.initials: DJ
authors.lastname: Figueroa
authors.forename: A D
authors.initials: AD
authors.lastname: Marmorstein
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: K
authors.initials: K
authors.lastname: Petrukhin
authors.forename: C T
authors.initials: CT
authors.lastname: Caskey
authors.forename: C P
authors.initials: CP
authors.lastname: Austin
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis*; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D006801:Humans; D008253:Macaca mulatta; D051379:Mice; D008969:Molecular Sequence Data; D009457:Neuroglia / Q000378:metabolism*; D057093:Orphan Nuclear Receptors; D010857:Pigment Epithelium of Eye / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014018:Tissue Distribution; D014157:Transcription Factors; D014162:Transfection
chemical_list: C020932:11-cis-retinal-binding protein; D002352:Carrier Proteins; C403073:NR2E3 protein, human; C485736:Nr2e3 protein, mouse; D057093:Orphan Nuclear Receptors; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors