title: The nucleolar PICT-1/GLTSCR2 protein forms homo-oligomers.
abstract: The human "protein interacting with carboxyl terminus 1" (PICT-1), also designated as the "glioma tumor suppressor candidate region 2 gene product", GLTSCR2, is a nucleolar protein whose activity is, as yet, unknown. Contradictory results regarding the role of PICT-1 in cancer have been reported, and PICT-1 has been suggested to function either as a tumor suppressor protein or as an oncogene. In this study, we demonstrate self-association of PICT-1. Through yeast two-hybrid assay, we identified PICT-1 as its own interaction partner. We confirmed the interaction of PICT-1 with itself by direct yeast two-hybrid assay and also showed self-association of PICT-1 in mammalian cells by co-immunoprecipitation and fluorescence resonance energy transfer assays. Furthermore, we confirmed direct self-association of PICT-1 by using in vitro microfluidic affinity binding assays. The later assay also identified the carboxy-terminal domain as mediating self-interaction of PICT-1. Glutaraldehyde cross-linking and gel-filtration assays suggest that PICT-1 forms dimers, though it may form higher-order complexes as well. Our findings add another layer of complexity in understanding the different functions of PICT-1 and may help provide insights regarding the activities of this protein.
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Borodianskiy-Shteinberg
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Inna
authors.initials: I
authors.lastname: Kalt
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Sarit
authors.initials: S
authors.lastname: Kipper
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Nofar
authors.initials: N
authors.lastname: Nachum
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Shiri
authors.initials: S
authors.lastname: Katz
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Maor H
authors.initials: MH
authors.lastname: Pauker
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Mira
authors.initials: M
authors.lastname: Barda-Saad
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002.
authors.forename: Doron
authors.initials: D
authors.lastname: Gerber
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel 5290002. Electronic address: saridr@mail.biu.ac.il.
authors.forename: Ronit
authors.initials: R
authors.lastname: Sarid
mesh_terms: D002850:Chromatography, Gel; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D047468:Immunoprecipitation; D046210:Microfluidic Analytical Techniques; D025941:Protein Interaction Mapping; D055503:Protein Multimerization; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: C500712:NOP53 protein, human; D025521:Tumor Suppressor Proteins
keywords: glioma tumor suppressor candidate region 2 gene product, GLTSCR2; nucleolus; oligomer; p53; protein interacting with carboxyl terminus 1, PICT-1