|Title||Suppression of SHP-2 and ERK signalling promotes self-renewal of mouse embryonic stem cells.|
|Publication Type||Journal Article|
|Year of Publication||1999|
|Authors||Burdon T, Stracey C, Chambers I, Nichols J, Smith A|
|Date Published||1999 Jun 1|
|Keywords||Animals, Antigens, CD, Calcium-Calmodulin-Dependent Protein Kinases, Cell Differentiation, Cell Division, Cells, Cultured, Chimera, Cytokine Receptor gp130, DNA-Binding Proteins, Enzyme Activation, Flavonoids, Gene Expression Regulation, Developmental, Helminth Proteins, Intracellular Signaling Peptides and Proteins, Membrane Glycoproteins, Mice, Mitogen-Activated Protein Kinase 1, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases, Mutation, Protein Tyrosine Phosphatase, Non-Receptor Type 11, Protein Tyrosine Phosphatase, Non-Receptor Type 6, Protein Tyrosine Phosphatases, Signal Transduction, STAT3 Transcription Factor, Stem Cells, Suppression, Genetic, Trans-Activators, Transfection, Tyrosine|
The propagation of pluripotent mouse embryonic stem (ES) cells depends on signals transduced through the cytokine receptor subunit gp130. Signalling molecules activated downstream of gp130 in ES cells include STAT3, the protein tyrosine phosphatase SHP-2, and the mitogen-activated protein kinases, ERK1 and ERK2. A chimaeric receptor in which tyrosine 118 in the gp130 cytoplasmic domain was mutated did not engage SHP-2 and failed to activate ERKs. However, this receptor did support ES cell self-renewal. In fact, stem cell colonies formed at 100-fold lower concentrations of cytokine than the unmodified receptor. Moreover, altered ES cell morphology and growth were observed at high cytokine concentrations. These indications of deregulated signalling in the absence of tyrosine 118 were substantiated by sustained activation of STAT3. Confirmation that ERK activation is not required for self-renewal was obtained by propagation of pluripotent ES cells in the presence of the MEK inhibitor PD098059. In fact, the growth of undifferentiated ES cells was enhanced by culture in PD098059. Thus activation of ERKs appears actively to impair self-renewal. These data imply that the self-renewal signal from gp130 is a finely tuned balance of positive and negative effectors.
|Alternate Journal||Dev. Biol.|