TY - JOUR
T1 - Activin A stimulates mitogenesis in Swiss 3T3 fibroblasts without activation of mitogen-activated protein kinases
AU - Sakurai, Takeshi
AU - Abe, Yoichiro
AU - Kasuya, Yoshitoshi
AU - Takuwa, Noriko
AU - Shiba, Reiko
AU - Yamashita, Takayuki
AU - Endo, Takeshi
AU - Goto, Katsutoshi
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1994/5/13
Y1 - 1994/5/13
N2 - Activin A stimulated DNA synthesis and transient c-fos expression in quiescent Swiss 3T3 fibroblasts. The activin A-induced DNA synthesis was dose-dependent with a half-maximal effect obtained at 0.3 nM. The maximal response obtained at 10 nM was comparable with that induced by 5 ng/ml basic fibroblast growth factor, Swiss 3T3 fibroblasts expressed abundant high affinity binding sites for 125I-labeled activin A with a K(d) value of 0.63 nM and the number of binding sites at 24,000/cell. Northern blot analysis revealed that Swiss 3T3 fibroblasts express a high level of type II activin receptor mRNA. In an attempt to elucidate the mechanism of mitogenic action of activin A2 we examined the effect of activin A on mitogen- activated protein kinase activation. Unexpectedly, however, activin A did not induce kinase activation under conditions in which basic fibroblast growth factor and endothelin-I at similar or even less potent mitogenic concentrations did. Furthermore, activin A did not induce phosphorylation of the Erk2 species of mitogen-activated protein kinase. These observations strongly suggest that the activation of mitogen-activated protein kinase is not a necessary step for activin A-induced DNA synthesis in Swiss 3T3 fibroblasts.
AB - Activin A stimulated DNA synthesis and transient c-fos expression in quiescent Swiss 3T3 fibroblasts. The activin A-induced DNA synthesis was dose-dependent with a half-maximal effect obtained at 0.3 nM. The maximal response obtained at 10 nM was comparable with that induced by 5 ng/ml basic fibroblast growth factor, Swiss 3T3 fibroblasts expressed abundant high affinity binding sites for 125I-labeled activin A with a K(d) value of 0.63 nM and the number of binding sites at 24,000/cell. Northern blot analysis revealed that Swiss 3T3 fibroblasts express a high level of type II activin receptor mRNA. In an attempt to elucidate the mechanism of mitogenic action of activin A2 we examined the effect of activin A on mitogen- activated protein kinase activation. Unexpectedly, however, activin A did not induce kinase activation under conditions in which basic fibroblast growth factor and endothelin-I at similar or even less potent mitogenic concentrations did. Furthermore, activin A did not induce phosphorylation of the Erk2 species of mitogen-activated protein kinase. These observations strongly suggest that the activation of mitogen-activated protein kinase is not a necessary step for activin A-induced DNA synthesis in Swiss 3T3 fibroblasts.
UR - http://www.scopus.com/inward/record.url?scp=0028358168&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028358168&partnerID=8YFLogxK
M3 - Article
C2 - 8188692
AN - SCOPUS:0028358168
VL - 269
SP - 14118
EP - 14122
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 19
ER -