Ubiquitin ligase SMURF2 enhances epidermal growth factor receptor stability and tyrosine-kinase inhibitor resistance.

Autor:	Ray P; Department of Radiation Oncology, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Raghunathan K; Department of Biophysics, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Ahsan A; Department of Radiation Oncology, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Allam US; Department of Radiation Oncology, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Shukla S; Department of Radiation Oncology, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Basrur V; Department of Pathology, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Veatch S; Department of Biophysics, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Lawrence TS; Department of Radiation Oncology, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Nyati MK; Department of Radiation Oncology, The University of Michigan Medical School, Ann Arbor, Michigan, USA., Ray D; Department of Radiation Oncology, The University of Michigan Medical School, Ann Arbor, Michigan, USA dipray@umich.edu.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2020 Sep 04; Vol. 295 (36), pp. 12661-12673. Date of Electronic Publication: 2020 Jul 15.
DOI:	10.1074/jbc.RA120.013519
Abstrakt:	The discovery of activating epidermal growth factor receptor (EGFR) mutations spurred the use of EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib, as the first-line treatment of lung cancers. We previously reported that differential degradation of TKI-sensitive ( e.g. L858R) and resistant (T790M) EGFR mutants upon erlotinib treatment correlates with drug sensitivity. We also reported that SMAD ubiquitination regulatory factor 2 (SMURF2) ligase activity is important in stabilizing EGFR. However, the molecular mechanisms involved remain unclear. Here, using in vitro and in vivo ubiquitination assays, MS, and superresolution microscopy, we show SMURF2-EGFR functional interaction is important for EGFR stability and response to TKI. We demonstrate that L858R/T790M EGFR is preferentially stabilized by SMURF2-UBCH5 (an E3-E2)-mediated polyubiquitination. We identified four lysine residues as the sites of ubiquitination and showed that replacement of one of them with acetylation-mimicking glutamine increases the sensitivity of mutant EGFR to erlotinib-induced degradation. We show that SMURF2 extends membrane retention of EGF-bound EGFR, whereas SMURF2 knockdown increases receptor sorting to lysosomes. In lung cancer cell lines, SMURF2 overexpression increased EGFR levels, improving TKI tolerance, whereas SMURF2 knockdown decreased EGFR steady-state levels and sensitized lung cancer cells. Overall, we propose that SMURF2-mediated polyubiquitination of L858R/T790M EGFR competes with acetylation-mediated receptor internalization that correlates with enhanced receptor stability; therefore, disruption of the E3-E2 complex may be an attractive target to overcome TKI resistance. Competing Interests: Conflict of interest—The authors declare that they have no conflicts of interest with the contents of this article. (© 2020 Ray et al.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu