Deubiquitinating enzyme USP37 regulating oncogenic function of 14-3-3γ

Abstract

14-3-3 is a family of highly conserved protein that is involved in a number of cellular processes. In this study, we identified that the high expression of 14-3-3γ in various cancer cell lines correlates with the invasiveness of the cancer cells. Overexpression of 14-3-3γ causes changes to the morphologic characteristics of cell transformation, and promotes cell migration and invasion. The cells overexpressed with 14-3-3γ have been shown to stimulate foci and tumor formation in SCID-NOD mice in concert with signaling components as reported with the 14-3-3β. In our previous study, we demonstrated that 14-3-3γ inhibits apoptotic cell death and mediates the promotion of cell proliferation in immune cell lines. Earlier, binding partners for 14-3-3γ were defined by screening. We found that USP37, one of deubiquitinating enzymes (DUBs), belongs to this binding partner group. Therefore, we investigated whether 14-3-3γ mediates proliferation in cancer cells, and 14-3-3γ by USP37 is responsible for promoting cell proliferation. Importantly, we found that USP37 regulates the stability of ubiquitin-conjugated 14-3-3γ through its catalytic activity. This result implies that the interactive behavior between USP37 and 14-3-3γ could be involved in the regulation of 14-3-3γ degradation. When all these findings are considered together, USP37 is shown to be a specific DUB that prevents 14-3-3γ degradation, which may contribute to malignant transformation via MAPK signaling pathway, possibly providing a new target for therapeutic objectives of cancer.

Regulation of USP37 Expression by REST-Associated G9a-Dependent Histone Methylation

“…The retinoic acid receptor alpha (RARA) and the promyelocytic leukemia zinc finger (PLZF) fusion protein is a target of USP37 and the stabilization of PLZF and oncogenic transformation of acute promyelocytic leukemia cells has been attributed to USP37 (16). USP37 activity is believed to underlie the overexpression of 14-3-3γ protein and the consequent increase in proliferation of leukemia cells, providing support for an oncogenic role for USP37 (44). …”

Role of Deubiquitinases in Human Cancers: Potential Targeted Therapy

“…The E3 ligases participate at almost every phase, indicating the importance of ubiquitination and deubiquitination in regulating the cell cycle [20,21]. 14-3-3γ [97] The ability to advance through different stages of the cell cycle regardless of inhibitory signals is one of the hallmarks of cancer. A large number of DUBs have been found to play roles in cell cycle control of cancers via the regulation of different cell cycle checkpoints.…”

RNPS1 is modulated by ubiquitin‐specific protease 4

“…Protein was successfully eluted from beads by boiling with 2 9 SDS buffer followed by western blotting using an anti-Myc antibody (mouse monoclonal; dilution 1 : 1000; Santa Cruz Biotechnology) [40,41]. Escherichia coli BL21 (DE3) cells transformed with an expression vector for GST-RNPS1 were grown until A 600 of 0.6-0.8 was reached and induced with 0.2 mM isopropyl thio-b-D-galactoside and 0.01% EtOH at 18°C for 22 h. Purified GST-RNPS1 protein from E. coli BL21 cells was incubated with GST-Bind Agarose Beads (ElpisBio, Daejeon, Korea) for 4 h at 18°C.…”

“…The beads were then washed with a washing buffer (0.1 M Tris-HCl at pH 7.4, 0.5 M NaCl, 20 mM imidazole at pH 7.4). Protein was successfully eluted from beads by boiling with 2 9 SDS buffer followed by western blotting using an anti-Myc antibody (mouse monoclonal; dilution 1 : 1000; Santa Cruz Biotechnology) [40,41].…”