title: Notch intracellular domain deficiency in nuclear localization activity retains the ability to enhance neural stem cell character and block neurogenesis in mammalian brain development.
abstract: Notch has a broad range of regulatory functions in many developmental processes, including hematopoiesis, neurogenesis, and angiogenesis. Notch has several key functional regions such as the RBP-Jκ/CBF1 association module (RAM) domain, nuclear localization signals (NLS), and ankyrin (ANK) repeats. However, previous reports assessing the level of importance of these domains in the Notch signaling pathway are controversial. In this study, we have assessed the level of contribution of each Notch domain to the regulation of mammalian neural stem cells in vivo as well as in vitro. Reporter assays and real-time polymerase chain reactions show that the ANK repeats and RAM domain are indispensable to the transactivation of Notch target genes, whereas a nuclear export signal (NES)-fused Notch intracellular domain (NICD) mutant defective in nuclear localization exerts a level of activity comparable to unmodified NICD. Transactivational ability appears to be tightly coupled to Notch functions during brain development. Unlike ANK repeats and RAM domain deletion mutants, NES-NICD recapitulates NICD features such as promotion of astrogenesis at the expense of neurogenesis in vitro and enhancement of neural stem cell character in vivo. Our data support the previous observation that intranuclear localization is not essential to the oncogenesis of Notch1 in certain types of cells and imply the importance of the noncanonical Notch signaling pathway in the regulation of mammalian neural stem cells.
authors.affiliation: 1 School of Biological Sciences, Seoul National University , Seoul, Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Jang
authors.forename: Sung-Hyun
authors.initials: SH
authors.lastname: Byun
authors.forename: Dasol
authors.initials: D
authors.lastname: Han
authors.forename: Junsub
authors.initials: J
authors.lastname: Lee
authors.forename: Juwan
authors.initials: J
authors.lastname: Kim
authors.forename: Nayeon
authors.initials: N
authors.lastname: Lee
authors.forename: Inhee
authors.initials: I
authors.lastname: Kim
authors.forename: Soojeong
authors.initials: S
authors.lastname: Park
authors.forename: Soobong
authors.initials: S
authors.lastname: Ha
authors.forename: Mookwang
authors.initials: M
authors.lastname: Kwon
authors.forename: Jyhyun
authors.initials: J
authors.lastname: Ahn
authors.forename: Woo-Jae
authors.initials: WJ
authors.lastname: Chung
authors.forename: Dae-Hyuk
authors.initials: DH
authors.lastname: Kweon
authors.forename: Jae Youl
authors.initials: JY
authors.lastname: Cho
authors.forename: Sunyoung
authors.initials: S
authors.lastname: Kim
authors.forename: Keejung
authors.initials: K
authors.lastname: Yoon
mesh_terms: D000818:Animals; D017089:Ankyrin Repeat; D001921:Brain / Q000196:embryology* / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D058953:Neural Stem Cells / Q000378:metabolism*; D055495:Neurogenesis / Q000502:physiology*; D019913:Nuclear Localization Signals / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
chemical_list: C497762:Notch1 protein, mouse; D019913:Nuclear Localization Signals; D051881:Receptor, Notch1