Photoreceptor-specific nuclear receptor NR2E3 functions as a transcriptional activator in rod photoreceptors.


Journal Article

NR2E3, a photoreceptor-specific orphan nuclear receptor, is believed to play a pivotal role in the differentiation of photoreceptors. Mutations in the human NR2E3 gene and its mouse ortholog are associated with enhanced S-cones and retinal degeneration. In order to gain insights into the NR2E3 function, we performed temporal and spatial expression analysis, yeast two-hybrid screening, promoter activity assays and co-immunoprecipitation studies. The Nr2e3 expression was localized preferentially to the rod, and not to the cone, photoreceptor nuclei in rodent retina. The yeast two-hybrid screening of a retinal cDNA library, using NR2E3 as the bait, identified another orphan nuclear receptor NR1D1 (Rev-erbalpha). The interaction of NR2E3 with NR1D1 was confirmed by glutathione S-transferase pulldown and co-immunoprecipitation experiments. In transient transfection studies using HEK 293 cells, both NR2E3 and NR1D1 activated the promoters of rod phototransduction genes synergistically with neural retina leucine zipper (NRL) and cone-rod homeobox (CRX). All four proteins, NR2E3, NR1D1, NRL and CRX, could be co-immunoprecipitated from the bovine retinal nuclear extract, suggesting their existence in a multi-protein transcriptional regulatory complex in vivo. Our results demonstrate that NR2E3 is involved in regulating the expression of rod photoreceptor-specific genes and support its proposed role in transcriptional regulatory network(s) during rod differentiation.

Full Text

Cited Authors

  • Cheng, H; Khanna, H; Oh, ECT; Hicks, D; Mitton, KP; Swaroop, A

Published Date

  • August 2004

Published In

Volume / Issue

  • 13 / 15

Start / End Page

  • 1563 - 1575

PubMed ID

  • 15190009

Pubmed Central ID

  • 15190009

Electronic International Standard Serial Number (EISSN)

  • 1460-2083

International Standard Serial Number (ISSN)

  • 0964-6906

Digital Object Identifier (DOI)

  • 10.1093/hmg/ddh173


  • eng