Abstract
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Journal of Biological Chemistry |
| Vol/bind | 277 |
| Udgave nummer | 48 |
| Sider (fra-til) | 46687-95 |
| Antal sider | 8 |
| ISSN | 0021-9258 |
| DOI | |
| Status | Udgivet - 2002 |
Bibliografisk note
Keywords: Animals; Blotting, Western; Cell Differentiation; Cell Division; Cell Line; Fluorescent Antibody Technique; Muscle, Skeletal; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins pp60(c-src); Rats; Signal TransductionAdgang til dokumentet
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I: Journal of Biological Chemistry, Bind 277, Nr. 48, 2002, s. 46687-95.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
}
TY - JOUR
T1 - The differentiation of skeletal muscle cells involves a protein-tyrosine phosphatase-alpha-mediated C-Src signaling pathway.
AU - Lu, Huogen
AU - Shah, Poonam
AU - Ennis, David
AU - Shinder, Gail
AU - Sap, Jan
AU - Le-Tien, Hoang
AU - Fantus, I George
N1 - Keywords: Animals; Blotting, Western; Cell Differentiation; Cell Division; Cell Line; Fluorescent Antibody Technique; Muscle, Skeletal; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins pp60(c-src); Rats; Signal Transduction
PY - 2002
Y1 - 2002
N2 - Protein-tyrosine phosphatase-alpha (PTPalpha) plays an important role in various cellular signaling events, including proliferation and differentiation. In this study, we established L6 cell lines either underexpressing or overexpressing PTPalpha by stable transfection of cells with antisense PTPalpha or with full-length wild-type human or mouse or double catalytic site Cys --> Ala mutant (DM8) PTPalpha cDNA. Expression of PTPalpha in these cell lines was determined by immunoblotting and immunofluorescence. Cells harboring antisense PTPalpha exhibited a significantly reduced growth rate and thymidine incorporation when compared with the wild-type L6 cells. In contrast, cells overexpressing PTPalpha showed more rapid (2-fold) proliferation. Myoblasts with diminished PTPalpha failed to undergo fusion and did not form myotubes in reduced serum whereas overexpression of PTPalpha promoted myogenesis 2 days earlier than wild-type L6 cells. Overexpression of phosphatase-inactive mutant PTPalpha recapitulated the phenotype of the antisense cells. The different myogenic activities of these cell lines were correlated with the expression of myogenin and creatine kinase activity. Consistent with previous reports, PTPalpha positively regulated the activity of the protein-tyrosine kinase Src. Treatment of L6 cells with PP2 or SU6656, specific inhibitors of Src family kinases, and transient transfection of dominant-inhibitory Src inhibited the formation of myotubes and expression of myogenin. Moreover, enhanced expression of PTPalpha and activation of Src was detected during myogenesis. Together, these data indicate that PTPalpha is involved in the regulation of L6 myoblast growth and skeletal muscle cell differentiation via an Src-mediated signaling pathway.
AB - Protein-tyrosine phosphatase-alpha (PTPalpha) plays an important role in various cellular signaling events, including proliferation and differentiation. In this study, we established L6 cell lines either underexpressing or overexpressing PTPalpha by stable transfection of cells with antisense PTPalpha or with full-length wild-type human or mouse or double catalytic site Cys --> Ala mutant (DM8) PTPalpha cDNA. Expression of PTPalpha in these cell lines was determined by immunoblotting and immunofluorescence. Cells harboring antisense PTPalpha exhibited a significantly reduced growth rate and thymidine incorporation when compared with the wild-type L6 cells. In contrast, cells overexpressing PTPalpha showed more rapid (2-fold) proliferation. Myoblasts with diminished PTPalpha failed to undergo fusion and did not form myotubes in reduced serum whereas overexpression of PTPalpha promoted myogenesis 2 days earlier than wild-type L6 cells. Overexpression of phosphatase-inactive mutant PTPalpha recapitulated the phenotype of the antisense cells. The different myogenic activities of these cell lines were correlated with the expression of myogenin and creatine kinase activity. Consistent with previous reports, PTPalpha positively regulated the activity of the protein-tyrosine kinase Src. Treatment of L6 cells with PP2 or SU6656, specific inhibitors of Src family kinases, and transient transfection of dominant-inhibitory Src inhibited the formation of myotubes and expression of myogenin. Moreover, enhanced expression of PTPalpha and activation of Src was detected during myogenesis. Together, these data indicate that PTPalpha is involved in the regulation of L6 myoblast growth and skeletal muscle cell differentiation via an Src-mediated signaling pathway.
U2 - 10.1074/jbc.M209643200
DO - 10.1074/jbc.M209643200
M3 - Journal article
C2 - 12351660
SN - 0021-9258
VL - 277
SP - 46687
EP - 46695
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 48
ER -