Orphan nuclear receptor of retinal photoreceptor cells. Transcriptional factor that is an activator of rod development and repressor of cone development. Binds the promoter region of a number of rod- and cone-specific genes, including rhodopsin, M- and S-opsin and rod-specific phosphodiesterase beta subunit. Enhances rhodopsin expression. Represses M- and S-cone opsin expression. Homodimer. Interacts with PIAS3; the interaction sumoylates NR2E3 and promotes repression of cone-specific gene transcription and activation of rod-specific genes (By similarity). Component of a rod photoreceptor complex that includes NR2E3, PIAS3, NRL, CRX and/or NR1D1. Binds directly in the complex with CRX, PIAS3 and NR1D1 (By similarity). Interacts (via the DNA-binding domain) with CRX (via its DNA binding domain); the interaction represses S- and M-cone opsin expression (By similarity). Di- and tri-sumoylated in developing retina. PIAS3-mediated sumoylation is required for repression of cone-specific gene expression and rod photoreceptor development. Sumoylation on Lys-186 appears to be the main site. Belongs to the nuclear hormone receptor family.