title: β-Catenin recognizes a specific RNA motif in the cyclooxygenase-2 mRNA 3'-UTR and interacts with HuR in colon cancer cells.
abstract: RNA-binding proteins regulate multiple steps of RNA metabolism through both dynamic and combined binding. In addition to its crucial roles in cell adhesion and Wnt-activated transcription in cancer cells, β-catenin regulates RNA alternative splicing and stability possibly by binding to target RNA in cells. An RNA aptamer was selected for specific binding to β-catenin to address RNA recognition by β-catenin more specifically. Here, we characterized the structural properties of the RNA aptamer as a model and identified a β-catenin RNA motif. Similar RNA motif was found in cellular RNA, Cyclooxygenase-2 (COX-2) mRNA 3'-untranslated region (3'-UTR). More significantly, the C-terminal domain of β-catenin interacted with HuR and the Armadillo repeat domain associated with RNA to form the RNA-β-catenin-HuR complex in vitro and in cells. Furthermore, the tertiary RNA-protein complex was predominantly found in the cytoplasm of colon cancer cells; thus, it might be related to COX-2 protein level and cancer progression. Taken together, the β-catenin RNA aptamer was valuable for deducing the cellular RNA aptamer and identifying novel and oncogenic RNA-protein networks in colon cancer cells.
authors.affiliation: Department of Molecular Biology, National Research Lab for RNA Cell Biology, BK21 Graduate Program for RNA Biology, Institute of Nanosensor and Biotechnology, Dankook University, Yongin, Gyeonggi-do 448-701, Republic of Korea.
authors.forename: Inae
authors.initials: I
authors.lastname: Kim
authors.forename: Hoyun
authors.initials: H
authors.lastname: Kwak
authors.forename: Hee Kyu
authors.initials: HK
authors.lastname: Lee
authors.forename: Soonsil
authors.initials: S
authors.lastname: Hyun
authors.forename: Sunjoo
authors.initials: S
authors.lastname: Jeong
mesh_terms: D020413:3' Untranslated Regions; D052157:Aptamers, Nucleotide / Q000737:chemistry; D001665:Binding Sites; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000235:genetics*; D051959:ELAV Proteins / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D059372:Nucleotide Motifs; D054730:Protein Interaction Domains and Motifs; D012333:RNA, Messenger / Q000737:chemistry; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D051176:beta Catenin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020413:3' Untranslated Regions; D052157:Aptamers, Nucleotide; D051959:ELAV Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D051176:beta Catenin; D051546:Cyclooxygenase 2