title: A novel role of proteasomal β1 subunit in tumorigenesis.
abstract: p27Kip1 is a key cell-cycle regulator whose level is primarily regulated by the ubiquitin-proteasome degradation pathway. Its β1 subunit is one of seven β subunits that form the β-ring of the 20S proteasome, which is responsible for degradation of ubiquitinated proteins. We report here that the β1 subunit is up-regulated in oesophageal cancer tissues and some ovarian cancer cell lines. It promotes cell growth and migration, as well as colony formation. β1 binds and degrades p27Kip1directly. Interestingly, the lack of phosphorylation at Ser158 of the β1 subunit promotes degradation of p27Kip1. We therefore propose that the β1 subunit plays a novel role in tumorigenesis by degrading p27Kip1.
authors.affiliation: Xiamen University School of Life Sciences, Xiamen, Fujian, People's Republic of China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Yuan
authors.forename: Yana
authors.initials: Y
authors.lastname: Ma
authors.forename: Pan
authors.initials: P
authors.lastname: You
authors.forename: Wenbo
authors.initials: W
authors.lastname: Lin
authors.forename: Haojie
authors.initials: H
authors.lastname: Lu
authors.forename: Yinhua
authors.initials: Y
authors.lastname: Yu
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Jiang
authors.forename: Pengyuan
authors.initials: P
authors.lastname: Yang
authors.forename: Qilin
authors.initials: Q
authors.lastname: Ma
authors.forename: Tao
authors.initials: T
authors.lastname: Tao
mesh_terms: D063646:Carcinogenesis / Q000378:metabolism*; D002465:Cell Movement; D049109:Cell Proliferation; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000737:chemistry / Q000378:metabolism*; D004938:Esophageal Neoplasms / Q000201:enzymology; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000502:physiology*; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D059748:Proteolysis; D015854:Up-Regulation
chemical_list: C436291:CDKN1B protein, human; D050760:Cyclin-Dependent Kinase Inhibitor p27; C577981:PSMB1 protein, human; D046988:Proteasome Endopeptidase Complex