title: Biochemical characterization and cellular effects of CADASIL mutants of NOTCH3.
abstract: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the best understood cause of dominantly inherited stroke and results from NOTCH3 mutations that lead to NOTCH3 protein accumulation and selective arterial smooth muscle degeneration. Previous studies show that NOTCH3 protein forms multimers. Here, we investigate protein interactions between NOTCH3 and other vascular Notch isoforms and characterize the effects of elevated NOTCH3 on smooth muscle gene regulation. We demonstrate that NOTCH3 forms heterodimers with NOTCH1, NOTCH3, and NOTCH4. R90C and C49Y mutant NOTCH3 form complexes which are more resistant to detergents than wild type NOTCH3 complexes. Using quantitative NOTCH3-luciferase clearance assays, we found significant inhibition of mutant NOTCH3 clearance. In coculture assays of NOTCH function, overexpressed wild type and mutant NOTCH3 significantly repressed NOTCH-regulated smooth muscle transcripts and potently impaired the activity of three independent smooth muscle promoters. Wildtype and R90C recombinant NOTCH3 proteins applied to cell cultures also blocked canonical Notch fuction. We conclude that CADASIL mutants of NOTCH3 complex with NOTCH1, 3, and 4, slow NOTCH3 clearance, and that overexpressed wild type and mutant NOTCH3 protein interfere with key NOTCH-mediated functions in smooth muscle cells.
authors.affiliation: Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: He
authors.initials: H
authors.lastname: Meng
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Zhang
authors.forename: Genggeng
authors.initials: G
authors.lastname: Yu
authors.forename: Soo Jung
authors.initials: SJ
authors.lastname: Lee
authors.forename: Y Eugene
authors.initials: YE
authors.lastname: Chen
authors.forename: Igor
authors.initials: I
authors.lastname: Prudovsky
authors.forename: Michael M
authors.initials: MM
authors.lastname: Wang
mesh_terms: D046589:CADASIL / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D005110:Extracellular Space / Q000378:metabolism; D057809:HEK293 Cells; D006706:Homeostasis / Q000235:genetics; D006801:Humans; D009130:Muscle, Smooth / Q000378:metabolism / Q000473:pathology; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D000071656:Receptor, Notch3; D051880:Receptors, Notch / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D012995:Solubility
chemical_list: D050505:Mutant Proteins; C499374:NOTCH3 protein, human; D000071656:Receptor, Notch3; D051880:Receptors, Notch