title: RBFOX3 regulates Claudin-1 expression in human lung tissue via attenuation of proteasomal degradation.
abstract: RBFOX3, a nuclear RNA-binding protein, is well known as a regulator of alternative pre-mRNA splicing during neuronal development. However, other functions of RBFOX3 are poorly understood. Here, we investigated the function of RBFOX3 in the cytoplasm with respect to regulation of Claudin-1 expression. In human lung tissue, Claudin-1 is higher in RBFOX3-positive cells than in RBFOX3-negative cells. Immunostaining and mRNA quantification revealed that protein levels, but not mRNA levels, of Claudin-1 are increased by RBFOX3. In addition, cycloheximide treatment of human lung cancer cells revealed that RBFOX3 increases the stability of Claudin-1 through attenuation of its ubiquitination. Our study provides insights into the molecular mechanisms by which RBFOX3 regulates Claudin-1 expression in human lung tissue.
authors.affiliation: Department of Biochemistry, Chungnam National University, Daejeon 34134, Republic of Korea.
authors.forename: Yong-Eun
authors.initials: YE
authors.lastname: Kim
authors.affiliation: Department of Biochemistry, Chungnam National University, Daejeon 34134, Republic of Korea.
authors.forename: Sunkyung
authors.initials: S
authors.lastname: Choi
authors.affiliation: Department of Pathology, Daejeon Saint Mary's Hospital, The Catholic University of Korea, Daejeon 34943, Republic of Korea kimkk@cnu.ac.kr jkim@catholic.ac.kr.
authors.forename: Jong Ok
authors.initials: JO
authors.lastname: Kim
authors.affiliation: Department of Biochemistry, Chungnam National University, Daejeon 34134, Republic of Korea kimkk@cnu.ac.kr jkim@catholic.ac.kr.
authors.forename: Kee K
authors.initials: KK
authors.lastname: Kim
mesh_terms: D000072283:A549 Cells; D034961:Antigens, Nuclear / Q000378:metabolism*; D062445:Claudin-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D059748:Proteolysis; D012333:RNA, Messenger / Q000235:genetics; D054875:Ubiquitination
chemical_list: D034961:Antigens, Nuclear; D062445:Claudin-1; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C506808:neuronal nuclear antigen NeuN, human; D046988:Proteasome Endopeptidase Complex
keywords: RBFOX3; lung tissue; protein stability; tight junctions; ubiquitin-proteasomal degradation