title: Orphan Nuclear Receptor NR4A1 Binds a Novel Protein Interaction Site on Anti-apoptotic B Cell Lymphoma Gene 2 Family Proteins.
abstract: B cell lymphoma gene 2 (Bcl-2) family proteins are key regulators of programmed cell death and important targets for drug discovery. Pro-apoptotic and anti-apoptotic Bcl-2 family proteins reciprocally modulate their activities in large part through protein interactions involving a motif known as BH3 (Bcl-2 homology 3). Nur77 is an orphan member of the nuclear receptor family that lacks a BH3 domain but nevertheless binds certain anti-apoptotic Bcl-2 family proteins (Bcl-2, Bfl-1, and Bcl-B), modulating their effects on apoptosis and autophagy. We used a combination of NMR spectroscopy-based methods, mutagenesis, and functional studies to define the interaction site of a Nur77 peptide on anti-apoptotic Bcl-2 family proteins and reveal a novel interaction surface. Nur77 binds adjacent to the BH3 peptide-binding crevice, suggesting the possibility of cross-talk between these discrete binding sites. Mutagenesis of residues lining the identified interaction site on Bcl-B negated the interaction with Nur77 protein in cells and prevented Nur77-mediated modulation of apoptosis and autophagy. The findings establish a new protein interaction site with the potential to modulate the apoptosis and autophagy mechanisms governed by Bcl-2 family proteins.
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Paulo H C
authors.initials: PHC
authors.lastname: Godoi
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Rachel P
authors.initials: RP
authors.lastname: Wilkie-Grantham
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Asami
authors.initials: A
authors.lastname: Hishiki
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Renata
authors.initials: R
authors.lastname: Sano
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Matsuzawa
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yanagi
authors.affiliation: Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Munte
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Ya
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037.
authors.forename: Francesca M
authors.initials: FM
authors.lastname: Marassi
authors.affiliation: Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany.
authors.forename: Hans R
authors.initials: HR
authors.lastname: Kalbitzer
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037,. Electronic address: smatsuzawa@sbpdiscovery.org.
authors.forename: Shu-Ichi
authors.initials: SI
authors.lastname: Matsuzawa
authors.affiliation: Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California 92037,; Roche, Pharma Research and Early Development, Basel 4070, Switzerland. Electronic address: John_C.Reed@roche.com.
authors.forename: John C
authors.initials: JC
authors.lastname: Reed
mesh_terms: D006801:Humans; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1 / Q000378:metabolism*; D011485:Protein Binding; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry / Q000378:metabolism*
chemical_list: C539821:NR4A1 protein, human; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D019253:Proto-Oncogene Proteins c-bcl-2
keywords: B cell lymphoma 2 (Bcl-2) family; Bcl-b; Bfl-1; NMR; NR4A1; Nur77; apoptosis; autophagy; protein-protein interaction