Presence of functional gap junctions in human embryonic stem cells

Stem Cells. 2004;22(6):883-9. doi: 10.1634/stemcells.22-6-883.


Gap junctions are intercellular channels that allow both chemical and electrical signaling between two adjacent cells. Gap junction intercellular communication has been implicated in the regulation of various cellular processes, including cell migration, cell proliferation, cell differentiation, and cell apoptosis. This study aimed to determine the presence and functionality of gap junctions in human embryonic stem cells (hESCs). Using reverse transcription--polymerase chain reaction and immunocytochemistry, we demonstrate that human ES cells express two gap junction proteins, connexin 43 and connexin 45. Western blot analysis revealed the presence of three phosphorylated forms (nonphosphorylated [NP], P1, and P2) of connexin 43, NP being prominent. Moreover, scrape loading/dye transfer assay indicates that human ES cells are coupled through functional gap junctions that are inhibited by protein kinase C activation and extracellular signal-regulated kinase inhibition.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Apoptosis
  • Blotting, Western
  • Cell Differentiation
  • Cell Movement
  • Cell Proliferation
  • Connexin 43 / metabolism
  • Connexins / metabolism
  • Embryo, Mammalian / cytology*
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Fluorescent Dyes / pharmacology
  • Gap Junctions / physiology*
  • Humans
  • Immunohistochemistry
  • Phosphorylation
  • Protein Kinase C / metabolism
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Stem Cells / cytology*


  • Connexin 43
  • Connexins
  • Fluorescent Dyes
  • RNA, Messenger
  • connexin 45
  • Protein Kinase C
  • Extracellular Signal-Regulated MAP Kinases