Identification and characterization of adenovirus early region 1B-associated protein 5 as a surface marker on undifferentiated human embryonic stem cells

Stem Cells Dev. 2011 Apr;20(4):609-20. doi: 10.1089/scd.2010.0265. Epub 2011 Jan 16.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Differentiation / metabolism*
  • Cell Differentiation
  • Cell Line
  • Cell Line, Tumor
  • Coculture Techniques
  • Down-Regulation
  • Embryonic Stem Cells / cytology
  • Embryonic Stem Cells / metabolism*
  • Flow Cytometry
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism*
  • Homeodomain Proteins / metabolism
  • Humans
  • Immunoprecipitation
  • Membrane Proteins / metabolism*
  • Mice
  • Molecular Sequence Data
  • Nanog Homeobox Protein
  • Neoplastic Stem Cells / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Phosphorylation
  • Pluripotent Stem Cells / cytology
  • Pluripotent Stem Cells / metabolism
  • SOXB1 Transcription Factors / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Antigens, Differentiation
  • HNRNPUL1 protein, human
  • Heterogeneous-Nuclear Ribonucleoproteins
  • Homeodomain Proteins
  • Membrane Proteins
  • NANOG protein, human
  • Nanog Homeobox Protein
  • Nuclear Proteins
  • SOX2 protein, human
  • SOXB1 Transcription Factors
  • Transcription Factors