title: Human selenium binding protein-1 (hSP56) interacts with VDU1 in a selenium-dependent manner.
abstract: Reduced expression of the 56-kDa human selenium binding protein-1 (hSP56) has been reported in many types of human malignancies, including prostate, lung, ovarian, thyroid and colorectal cancers. hSP56 also has been implicated in selenium-dependent cell growth inhibition. However, the molecular basis of hSP56's function has not been elucidated. In the present study, we identified von Hippel-Lindau protein (pVHL)-interacting deubiquitinating enzyme 1 (VDU1) as a protein partner of hSP56 using a yeast two-hybrid screen. The interaction between hSP56 and VDU1 was confirmed by yeast two-hybrid analysis and in vitro binding experiments. hSP56 and VDU1 co-localized in the perinuclear region of LNCaP human prostate cancer cells. The full-length VDU1 specifically interacted with a selenium-replete form of hSP56. We also demonstrate stable incorporation of selenium into hSP56, in a mode distinct from conventional selenocysteine-containing selenoproteins. These findings suggest that hSP56 may play a role in ubiquitination/deubiquitination-mediated protein degradation pathways in a selenium-dependent manner.
authors.affiliation: Laboratory for Cell and Molecular Biology, Division of Hematology and Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Jee-Yeong
authors.initials: JY
authors.lastname: Jeong
authors.forename: Yuxun
authors.initials: Y
authors.lastname: Wang
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Sytkowski
mesh_terms: D045744:Cell Line, Tumor; D006801:Humans; D012643:Selenium / Q000378:metabolism*; D051137:Selenium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D043222:Ubiquitin Thiolesterase / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: C495175:SELENBP1 protein, human; D051137:Selenium-Binding Proteins; C449799:USP33 protein, human; D043222:Ubiquitin Thiolesterase; D012643:Selenium