title: Identification and characterization of adenovirus early region 1B-associated protein 5 as a surface marker on undifferentiated human embryonic stem cells.
abstract: Pluripotent human embryonic stem cells (hESCs) provide appropriate systems for developmental studies and prospective donor cell sources for regenerative medicine. Identification of surface markers specific to hESCs is a prerequisite for studying hESC biology and can be used to generate clinical-level donor cell preparations that are free from tumorigenic undifferentiated hESCs. We previously reported the generation of monoclonal antibodies that specifically recognize hESC surface antigens using a decoy immunization strategy. In this study, we show that monoclonal antibody 57-C11 recognizes a phosphorylated form of adenovirus early region 1B-associated protein 5 (E1B-AP5). E1B-AP5 is a nuclear RNA-binding protein, but we report that 57-C11-reactive E1B-AP5 is expressed on the surface of undifferentiated hESCs. In undifferentiated hESCs, 57-C11-reactive E1B-AP5 is localized to SSEA3-, SSEA4-, TRA-1-60-, TRA-1-81-, OCT4-, SOX2-, and NANOG-positive hESCs. In mixtures of undifferentiated hESCs and hESC-derived neurons, 57-C11 exclusively recognizes undifferentiated hESCs but not hESC-derived neuronal cells. Further, the expression of 57-C11-reactive E1B-AP5 decreases upon differentiation. Our results demonstrate that 57-C11-reactive E1B-AP5 is a novel surface molecule that is involved in the undifferentiated state of hESCs. As far as we know, this is the first report demonstrating that heterogeneous nuclear RNA-binding protein is expressed on the surface of undifferentiated hESCs.
authors.affiliation: Department of Bioscience and Biotechnology, Institute of Bioscience, Sejong University, Seoul, Korea.
authors.forename: Hong Seo
authors.initials: HS
authors.lastname: Choi
authors.forename: Won-Tae
authors.initials: WT
authors.lastname: Kim
authors.forename: Hana
authors.initials: H
authors.lastname: Kim
authors.forename: Jum-Ji
authors.initials: JJ
authors.lastname: Kim
authors.forename: Ji-Yun
authors.initials: JY
authors.lastname: Ko
authors.forename: Sang-Wang
authors.initials: SW
authors.lastname: Lee
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Jang
authors.forename: Sang Jick
authors.initials: SJ
authors.lastname: Kim
authors.forename: Min-Jung
authors.initials: MJ
authors.lastname: Lee
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Jung
authors.forename: Julia
authors.initials: J
authors.lastname: Kzhyshkowska
authors.forename: Soo-Jong
authors.initials: SJ
authors.lastname: Um
authors.forename: Mi-Young
authors.initials: MY
authors.lastname: Lee
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Cheorl-Ho
authors.initials: CH
authors.lastname: Kim
authors.forename: Chun Jeih
authors.initials: CJ
authors.lastname: Ryu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D015536:Down-Regulation; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D000071317:Nanog Homeobox Protein; D014411:Neoplastic Stem Cells / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000943:Antigens, Differentiation; C475078:HNRNPUL1 protein, human; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D018398:Homeodomain Proteins; D008565:Membrane Proteins; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D009687:Nuclear Proteins; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors