mutations in the dna-binding domain of nr2e3 affect in vivo dimerization and interaction with crx突变的dna结合域与crx nr2e3影响体内二聚作用和交互.pdfVIP

Mutations in the DNA-Binding Domain of NR2E3 Affect In Vivo Dimerization and Interaction with CRX Raphael Roduit1,2.*, Pascal Escher1,2., Daniel F. Schorderet1,2,3 1 IRO, Institute for Research in Ophthalmology, Sion, Switzerland, 2 Department of Ophthalmology, University of Lausanne, Lausanne, Switzerland, 3 EPFL, Ecole ´ ´ Polytechnique Federale de Lausanne, Lausanne, Switzerland Abstract Background: NR2E3 (PNR) is an orphan nuclear receptor essential for proper photoreceptor determination and differentiation. In humans, mutations in NR2E3 have been associated with the recessively inherited enhanced short wavelength sensitive (S-) cone syndrome (ESCS) and, more recently, with autosomal dominant retinitis pigmentosa (adRP). NR2E3 acts as a suppressor of the cone generation program in late mitotic retinal progenitor cells. In adult rod photoreceptors, NR2E3 represses cone-specific gene expression and acts in concert with the transcription factors CRX and NRL to activate rod-specific genes. NR2E3 and CRX have been shown to physically interact in vitro through their respective DNA-binding domains (DBD). The DBD also contributes to homo- and heterodimerization of nuclear receptors. Methodology/Principal Findings: We analyzed NR2E3 homodimerization and NR2E3/CRX complex formation in an in vivo situation by Bioluminescence Resonance Energy Transfer (BRET2). NR2E3 wild-type protein formed homodimers in transiently transfected HEK293T cells. NR2E3 homodimerization was impaired in presence of disease-causing mutations in the DBD, except for the p.R76Q and p.R104W mutant proteins. Strikingly, the adRP-linked p.G56R mutant protein interacted with CRX with a similar efficiency to that of NR2E3 wild-type a