title: Insights into Autoregulation of Notch3 from Structural and Functional Studies of Its Negative Regulatory Region.
abstract: Notch receptors are transmembrane proteins that undergo activating proteolysis in response to ligand stimulation. A negative regulatory region (NRR) maintains receptor quiescence by preventing protease cleavage prior to ligand binding. We report here the X-ray structure of the NRR of autoinhibited human Notch3, and compare it with the Notch1 and Notch2 NRRs. The overall architecture of the autoinhibited conformation, in which three LIN12-Notch repeat (LNR) modules wrap around a heterodimerization domain, is preserved in Notch3, but the autoinhibited conformation of the Notch3 NRR is less stable. The Notch3 NRR uses a highly conserved surface on the third LNR module to form a dimer in the crystal. Similar homotypic interfaces exist in Notch1 and Notch2. Together, these studies reveal distinguishing structural features associated with increased basal activity of Notch3, demonstrate increased ligand-independent signaling for disease-associated mutations that map to the Notch3 NRR, and identify a conserved dimerization interface present in multiple Notch receptors.
authors.affiliation: Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA.
authors.forename: Tiancen
authors.initials: T
authors.lastname: Hu
authors.affiliation: Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Kittichoat
authors.initials: K
authors.lastname: Tiyanont
authors.affiliation: Department of Radiotherapy (MAASTRO)/GROW - School for Developmental Biology & Oncology, Maastricht University, Maastricht 6229, the Netherlands.
authors.forename: Roger
authors.initials: R
authors.lastname: Habets
authors.affiliation: Department of Radiotherapy (MAASTRO)/GROW - School for Developmental Biology & Oncology, Maastricht University, Maastricht 6229, the Netherlands.
authors.forename: Arjan J
authors.initials: AJ
authors.lastname: Groot
authors.affiliation: Department of Radiotherapy (MAASTRO)/GROW - School for Developmental Biology & Oncology, Maastricht University, Maastricht 6229, the Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Vooijs
authors.affiliation: Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Jon C
authors.initials: JC
authors.lastname: Aster
authors.affiliation: Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Chopra
authors.affiliation: Novartis Institutes for Biomedical Research, Cambridge, MA 02139, USA.
authors.forename: Christy
authors.initials: C
authors.lastname: Fryer
authors.affiliation: Department of Cancer Biology, Dana Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. Electronic address: stephen_blacklow@hms.harvard.edu.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Blacklow
mesh_terms: D045744:Cell Line, Tumor; D018360:Crystallography, X-Ray; D057809:HEK293 Cells; D006801:Humans; D008958:Models, Molecular; D020125:Mutation, Missense; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D059748:Proteolysis; D000071656:Receptor, Notch3; D051880:Receptors, Notch / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: C499374:NOTCH3 protein, human; D000071656:Receptor, Notch3; D051880:Receptors, Notch