Involvement of GSK-3β and DYRK1B in Differentiation-inducing Factor-3-induced Phosphorylation of Cyclin D1 in HeLa Cells

Sachio Morimoto,Toshiyuki Sasaguri,Yoshikazu Miwa,Jun Mori,Fumi Takahashi-Yanaga,Masato Hirata,Etsuko Matsuzaki,Yutaka Watanabe

doi:10.1074/jbc.m605205200

Sachio Morimoto, Toshiyuki Sasaguri + Show 6 more

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https://doi.org/10.1074/jbc.m605205200

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Abstract

Differentiation-inducing factors (DIFs) are putative morphogens that induce cell differentiation in Dictyostelium discoideum. We previously reported that DIF-3 activates glycogen synthase kinase-3beta (GSK-3beta), resulting in the degradation of cyclin D1 in HeLa cells. In this study, we investigated the effect of DIF-3 on cyclin D1 mutants (R29Q, L32A, T286A, T288A, and T286A/T288A) to clarify the precise mechanisms by which DIF-3 degrades cyclin D1 in HeLa cells. We revealed that T286A, T288A, and T286A/T288A mutants were resistant to DIF-3-induced degradation compared with wild-type cyclin D1, indicating that the phosphorylation of Thr(286) and Thr(288) were critical for cyclin D1 degradation induced by DIF-3. Indeed, DIF-3 markedly elevated the phosphorylation level of cyclin D1, and mutations introduced to Thr(286) and/or Thr(288) prevented the phosphorylation induced by DIF-3. Depletion of endogenous GSK-3beta and dual-specificity tyrosine phosphorylation regulated kinase 1B (DYRK1B) by RNA interference attenuated the DIF-3-induced cyclin D1 phosphorylation and degradation. The effect of DIF-3 on DYRK1B activity was examined and we found that DIF-3 also activated this kinase. Further, we found that not only GSK-3beta but also DYRK1B modulates cyclin D1 subcellular localization by the phosphorylation of Thr(288). These results suggest that DIF-3 induces degradation of cyclin D1 through the GSK-3beta- and DYRK1B-mediated threonine phosphorylation in HeLa cells.

Highlights

We found that GSK-3␤ and dual-specificity tyrosine phosphorylation regulated kinase 1B (DYRK1B) modulates cyclin D1 subcellular localization by the phosphorylation of Thr288. These results suggest that Differentiation-inducing factors (DIFs)-3 induces degradation of cyclin D1 through the GSK-3␤- and DYRK1B-mediated threonine phosphorylation in HeLa cells
The samples were incubated at 30 °C T288A, and T286A/T288A mutations significantly reduced the for 30 min, and the reaction was terminated by adding 10 ␮l of effect of DIF-3 (Fig. 1B)
We found that both residues play important roles in DIF-3-induced cyclin D1 degradation

Summary

Introduction

Science and Technology (a grant-in-aid for Scientific Research). The costs of publication of this article were defrayed in part by the payment of page charges. Depletion of endogenous GSK-3␤ and dual-specificity tyrosine phosphorylation regulated kinase 1B (DYRK1B) by RNA interference attenuated the DIF-3-induced cyclin D1 phosphorylation and degradation. These results suggest that DIF-3 induces degradation of cyclin D1 through the GSK-3␤- and DYRK1B-mediated threonine phosphorylation in HeLa cells.

Results

Conclusion