Ubiquitin carboxy-terminal hydrolase L1 binds to and stabilizes monoubiquitin in neuron

• Published in: Human molecular genetics 2003-08, Vol.12 (16), p.1945-1958
• Main Authors: Osaka, Hitoshi, Wang, Yu-Lai, Takada, Koji, Takizawa, Shuichi, Setsuie, Rieko, Li, Hang, Sato, Yae, Nishikawa, Kaori, Sun, Ying-Jie, Sakurai, Mikako, Harada, Takayuki, Hara, Yoko, Kimura, Ichiro, Chiba, Shigeru, Namikawa, Kazuhiko, Kiyama, Hiroshi, Noda, Mami, Aoki, Shunsuke, Wada, Keiji
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Brain - enzymology; Classical genetics, quantitative genetics, hybrids; Fundamental and applied biological sciences. Psychology; Gene Deletion; Genetics of eukaryotes. Biological and molecular evolution; Human; Mice - genetics; Mice, Mutant Strains; Molecular and cellular biology; Neurons - enzymology; Transfection; Ubiquitin - metabolism; Ubiquitin Thiolesterase - genetics; Ubiquitin Thiolesterase - metabolism
• ISSN: 0964-6906; 1460-2083; 1460-2083
• DOI: 10.1093/hmg/ddg211

Mammalian neuronal cells abundantly express a deubiquitylating enzyme, ubiquitin carboxy-terminal hydrolase 1 (UCH L1). Mutations in UCH L1 are linked to Parkinson's disease as well as gracile axonal dystrophy (gad) in mice. In contrast to the UCH L3 isozyme that is universally expressed in all tissues, UCH L1 is expressed exclusively in neurons and testis/ovary. We found that UCH L1 associates and colocalizes with monoubiquitin and elongates ubiquitin half-life. The gad mouse, in which the function of UCH L1 is lost, exhibited a reduced level of monoubiquitin in neurons. In contrast, overexpression of UCH L1 caused an increase in the level of ubiquitin in both cultured cells and mice. These data suggest that UCH L1, with avidity and affinity for ubiquitin, insures ubiquitin stability within neurons. This study is the first to show the function of UCH L1 in vivo.