title: Pluripotency transcription factor Sox2 is strongly adsorbed by heparin but requires a protein transduction domain for cell internalization.
abstract: The binding of protein transduction domain (PTD)-conjugated proteins to heparan sulfate is an important step in cellular internalization of macromolecules. Here, we studied the pluripotency transcription factor Sox2, with or without the nonaarginine (R9) PTD. Unexpectedly, we observed that Sox2 is strongly adsorbed by heparin and by the fibroblasts without the R9 PTD. However, only the R9Sox2 fusion protein is internalized by the cells. These results collectively show that binding to heparan sulfate is not sufficient for cellular uptake, thereby supporting a recent hypothesis that other proteins play a role in cell internalization of PTD-conjugated proteins.
authors: Department of Chemical Engineering, Stanford University, 381 North-South Mall, Stanford, CA 94305, USA.
authors: Cem
authors: C
authors: Albayrak
authors: William C
authors: WC
authors: Yang
authors: James R
authors: JR
authors: Swartz
mesh_terms: D002474:Cell-Free System / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D065150:Cellular Reprogramming; D006493:Heparin / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D055748:SOXB1 Transcription Factors / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D055748:SOXB1 Transcription Factors; D006493:Heparin