TLX/PNR

TLX/PNR (Tailless like receptor) is the orphan receptor NR2E subgroup of nuclear receptors (NR) superfamily of transcription factors. NR2E subclass is evolutionarily conserved in both vertebrates and invertebrates. Based on a phylogenetic analysis of DNA-binding domains, the NR2E subclass can be defined into two conserved groups: the NR2E1 subclass, which includes C. elegans nhr-67, Drosophila tailless and dissatisfaction, and vertebrate Tlx (NR2E2, NR2E4, NR2E1); and the NR2E3 subclass, which includes C. elegans fax-1 and vertebrate PNR (NR2E5, NR2E3). They bind the hexamer half-site AAGTCA, instead of the hexamer AGGTCA recognized by most other nuclear receptors, suggesting unique DNA-binding properties for NR2E class members. NR2E nuclear receptors play important roles in pattern formation and nervous system development.