1
|
Shimizu T, Nakamura T, Inaba H, Iwasa H, Maruyama J, Arimoto-Matsuzaki K, Nakata T, Nishina H, Hata Y. The RAS-interacting chaperone UNC119 drives the RASSF6-MDM2-p53 axis and antagonizes RAS-mediated malignant transformation. J Biol Chem 2020; 295:11214-11230. [PMID: 32554467 DOI: 10.1074/jbc.ra120.012649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 06/16/2020] [Indexed: 11/06/2022] Open
Abstract
The gene encoding the proto-oncogene GTPase RAS is frequently mutated in human cancers. Mutated RAS proteins trigger antiapoptotic and cell-proliferative signals and lead to oncogenesis. However, RAS also induces apoptosis and senescence, which may contribute to the eradication of cells with RAS mutations. We previously reported that Ras association domain family member 6 (RASSF6) binds MDM2 and stabilizes the tumor suppressor p53 and that the active form of KRAS promotes the interaction between RASSF6 and MDM2. We also reported that Unc-119 lipid-binding chaperone (UNC119A), a chaperone of myristoylated proteins, interacts with RASSF6 and regulates RASSF6-mediated apoptosis. In this study, using several human cancer cell lines, quantitative RT-PCR, RNAi-based gene silencing, and immunoprecipitation/-fluorescence and cell biology assays, we report that UNC119A interacts with the active form of KRAS and that the C-terminal modification of KRAS is required for this interaction. We also noted that the hydrophobic pocket of UNC119A, which binds the myristoylated peptides, is not involved in the interaction. We observed that UNC119A promotes the binding of KRAS to RASSF6, enhances the interaction between RASSF6 and MDM2, and induces apoptosis. Conversely, UNC119A silencing promoted soft-agar colony formation, migration, and invasiveness in KRAS-mutated cancer cells. We conclude that UNC119A promotes KRAS-mediated p53-dependent apoptosis via RASSF6 and may play a tumor-suppressive role in cells with KRAS mutations.
Collapse
Affiliation(s)
- Takanobu Shimizu
- Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takeshi Nakamura
- Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hironori Inaba
- Department of Cell Biology, Graduate School of Medical and Dental Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hiroaki Iwasa
- Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Junichi Maruyama
- Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kyoko Arimoto-Matsuzaki
- Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takao Nakata
- Department of Cell Biology, Graduate School of Medical and Dental Science, Tokyo Medical and Dental University, Tokyo, Japan.,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hiroshi Nishina
- Department of Developmental and Regenerative Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yutaka Hata
- Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan .,Center for Brain Integration Research, Tokyo Medical and Dental University, Tokyo, Japan
| |
Collapse
|