title: The USP21 short variant (USP21SV) lacking NES, located mostly in the nucleus in vivo, activates transcription by deubiquitylating ubH2A in vitro.
abstract: USP21 is a deubiquitylase that catalyzes isopeptide bond hydrolysis between ubiquitin and histone H2A. Since ubiqutylated H2A (ubH2A) represses transcription, USP21 plays a role in transcriptional activation. On the other hand, the localization of USP21 suggests it has an additional function in the cytoplasm. Here, we identified a USP21 short variant (USP21SV) lacking a nuclear export signal (NES). Differential localization of USP21SV, more in the nucleus than the USP21 long variant (USP21LV), suggests they have redundant roles in the cell. Ectopic expression of both USP21 variants decreased ubH2A in the nucleus. Furthermore, both recombinant USP21 variants activate transcription by deubiquitylating ubH2A in vitro. These data suggest multiple roles for USP21 in the ubiquitylation-deubiquitylation network in the cell.
authors.affiliation: Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, Japan ; Department of Surgery, Hiroshima University School of Medicine, Hiroshima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okuda
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohdan
authors.forename: Manabu
authors.initials: M
authors.lastname: Nakayama
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Koseki
authors.forename: Takeya
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006657:Histones / Q000378:metabolism*; D006801:Humans; D051379:Mice; D016415:Sequence Alignment; D043222:Ubiquitin Thiolesterase / Q000235:genetics / Q000378:metabolism*
chemical_list: D006657:Histones; C408875:USP21 protein, human; D043222:Ubiquitin Thiolesterase