TY - JOUR
T1 - Dictyostelium differentiation-inducing factor-3 activates glycogen synthase kinase-3β and degrades cyclin D1 in mammalian cells
AU - Takahashi-Yanaga, Fumi
AU - Taba, Yoji
AU - Miwa, Yoshikazu
AU - Kubohara, Yuzuru
AU - Watanabe, Yutaka
AU - Hirata, Masato
AU - Morimoto, Sachio
AU - Sasaguri, Toshiyuki
PY - 2003/3/14
Y1 - 2003/3/14
N2 - In search of chemical substances applicable for the treatment of cancer and other proliferative disorders, we studied the signal transduction of Dictyostelium differentiation-inducing factors (DIFs) in mammalian cells mainly using HeLa cells. Although DIF-1 and DIF-3 both strongly inhibited cell proliferation by inducing G0/G1 arrest, DIF-3 was more effective than DIF-1. DIF-3 suppressed cyclin D1 expression at both mRNA and protein levels, whereas the overexpression of cyclin D1 overrode DIF-3-induced cell cycle arrest. The DIF-3-induced decrease in the amount of cyclin D1 protein preceded the reduction in the level of cyclin D1 mRNA. The decrease in cyclin D1 protein seemed to be caused by accelerated proteolysis, since it was abrogated by N-acetyl-Leu-Leu-norleucinal, a proteasome inhibitor. DIF-3-induced degradation of cyclin D1 was also prevented by treatment with lithium chloride, an inhibitor of glycogen synthase kinase-3β (GSK-3β), suggesting that DIF-3 induced cyclin D1 proteolysis through the activation of GSK-3β. Indeed, DIF-3 dephosphorylated Ser9 and phosphorylated tyrosine on GSK-3β, and it stimulated GSK-3β activity in an in vitro kinase assay. Moreover, DIF-3 was revealed to induce the nuclear translocation of GSK-3β by immunofluorescent microscopy and immunoblotting of subcellular protein fractions. These results suggested that DIF-3 activates GSK-3β to accelerate the proteolysis of cyclin D1 and that this mechanism is involved in the DIF-3-induced G0/G1 arrest in mammalian cells.
AB - In search of chemical substances applicable for the treatment of cancer and other proliferative disorders, we studied the signal transduction of Dictyostelium differentiation-inducing factors (DIFs) in mammalian cells mainly using HeLa cells. Although DIF-1 and DIF-3 both strongly inhibited cell proliferation by inducing G0/G1 arrest, DIF-3 was more effective than DIF-1. DIF-3 suppressed cyclin D1 expression at both mRNA and protein levels, whereas the overexpression of cyclin D1 overrode DIF-3-induced cell cycle arrest. The DIF-3-induced decrease in the amount of cyclin D1 protein preceded the reduction in the level of cyclin D1 mRNA. The decrease in cyclin D1 protein seemed to be caused by accelerated proteolysis, since it was abrogated by N-acetyl-Leu-Leu-norleucinal, a proteasome inhibitor. DIF-3-induced degradation of cyclin D1 was also prevented by treatment with lithium chloride, an inhibitor of glycogen synthase kinase-3β (GSK-3β), suggesting that DIF-3 induced cyclin D1 proteolysis through the activation of GSK-3β. Indeed, DIF-3 dephosphorylated Ser9 and phosphorylated tyrosine on GSK-3β, and it stimulated GSK-3β activity in an in vitro kinase assay. Moreover, DIF-3 was revealed to induce the nuclear translocation of GSK-3β by immunofluorescent microscopy and immunoblotting of subcellular protein fractions. These results suggested that DIF-3 activates GSK-3β to accelerate the proteolysis of cyclin D1 and that this mechanism is involved in the DIF-3-induced G0/G1 arrest in mammalian cells.
UR - http://www.scopus.com/inward/record.url?scp=0037646484&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037646484&partnerID=8YFLogxK
U2 - 10.1074/jbc.M205768200
DO - 10.1074/jbc.M205768200
M3 - Article
C2 - 12522140
AN - SCOPUS:0037646484
VL - 278
SP - 9663
EP - 9670
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 11
ER -