title: Deubiquitinating enzymes regulate Hes1 stability and neuronal differentiation.
abstract: Hairy and enhancer of split 1 (Hes1), a basic helix-loop-helix transcriptional repressor protein, regulates the maintenance of neural stem/progenitor cells by repressing proneural gene expression via Notch signaling. Previous studies showed that Hes1 expression oscillates in both mouse embryonic stem cells and neural stem cells, and that the oscillation contributes to their potency and differentiation fates. This oscillatory expression depends on the stability of Hes1, which is rapidly degraded by the ubiquitin/proteasome pathway. However, the detailed molecular mechanisms governing Hes1 stability remain unknown. We analyzed Hes1-interacting deubiquitinases purified from mouse embryonic stem cells using an Hes1-specific antibody, and identified the ubiquitin-specific protease 27x (Usp27x) as a new regulator of Hes1. We found that Hes1 was deubiquitinated and stabilized by Usp27x and its homologs ubiquitin-specific protease 22 (Usp22) and ubiquitin-specific protease 51 (Usp51). Knockdown of Usp22 shortened the half-life of Hes1, delayed its oscillation, and enhanced neuronal differentiation in mouse developing brain, whereas mis-expression of Usp27x reduced neuronal differentiation. These results suggest that these deubiquitinases modulate Hes1 protein dynamics by removing ubiquitin molecules, and thereby regulate neuronal differentiation of stem cells.
authors.affiliation: Institute for Virus Research, Kyoto University, Japan.|Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), Kawaguchi, Japan.|Graduate School of Medicine, Kyoto University, Japan.|Graduate School of Biostudies, Kyoto University, Japan.
authors.forename: Taeko
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Institute for Virus Research, Kyoto University, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Iwamoto
authors.affiliation: Institute for Virus Research, Kyoto University, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takashima
authors.affiliation: Institute for Virus Research, Kyoto University, Japan.|Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), Kawaguchi, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Isomura
authors.affiliation: Department of Anatomy, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kosodo
authors.affiliation: Division of Molecular and Developmental Biology, National Institute of Genetics, Shizuoka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kawakami
authors.affiliation: Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nishioka
authors.affiliation: Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, Japan.
authors.forename: Kozo
authors.initials: K
authors.lastname: Kaibuchi
authors.affiliation: Institute for Virus Research, Kyoto University, Japan.|Japan Science and Technology Agency, Core Research for Evolutional Science and Technology (CREST), Kawaguchi, Japan.|Graduate School of Medicine, Kyoto University, Japan.|Graduate School of Biostudies, Kyoto University, Japan.|World Premier International Research Initiative/Institute for Integrated Cell and Material Sciences, Kyoto University, Japan.
authors.forename: Ryoichiro
authors.initials: R
authors.lastname: Kageyama
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002454:Cell Differentiation; D010450:Endopeptidases / Q000502:physiology; D057809:HEK293 Cells; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology; D000072056:Transcription Factor HES-1; D043222:Ubiquitin Thiolesterase; D064570:Ubiquitin-Specific Proteases / Q000502:physiology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D010450:Endopeptidases; D018398:Homeodomain Proteins; D000072056:Transcription Factor HES-1; D043222:Ubiquitin Thiolesterase; D064570:Ubiquitin-Specific Proteases; C489734:Hes1 protein, mouse; C584444:USP22 protein, mouse
keywords: Hes1; basic helix-loop-helix transcription factor (bHLH); deubiquitination; neurodevelopment; oscillation