SPOP
Speckle-type POZ protein (SPOP) functions as an E3 ubiquitin ligase adaptor that mediates substrate-specific ubiquitination and proteasomal degradation[1]. Mechanistically, SPOP targets proteins such as FADD and GLI3, regulating NF-κB and Sonic hedgehog (SHH) signaling pathways, respectively, which influence cancer cell proliferation and migration[2][3]. In hepatoblastoma, SPOP acts as a tumor suppressor by modulating SLC7A1 stability and arginine metabolism through the PI3K/Akt pathway[4]. The MATH domain of SPOP is critical for recognizing diverse substrates, facilitating the orchestration of multiple cellular processes and maintaining protein homeostasis[1]. Compared with related isoforms or mutants, SPOP exhibits substrate specificity that determines differential signaling outcomes in various disease contexts[2][3]. Small molecules targeting post-translational modification (PTM) isoforms of SPOP and other ubiquitin ligases provide opportunities for isoform-selective modulation and precision therapeutic design[5]. In experimental applications, SPOP overexpression reduces tumor growth, induces apoptosis, and modulates immune signaling, highlighting its utility as a functional biomarker and therapeutic target in cancer research[6]. These findings collectively emphasize the biological relevance of SPOP in regulating protein degradation, isoform-specific pathway modulation, and its potential exploitation in experimental and therapeutic strategies[2][4][6][1][3][5].
References:
- [1]. Niu Y, et al. SPOP enhances FADD degradation and decreases the activeness of the NF-κB signaling pathway in prostate cancer: an in vitro study. Transl Androl Urol. 2024 Dec 31;13(12):2787-2800. [Content Brief]
- [2]. He W, et al. S119N Mutation of the E3 Ubiquitin Ligase SPOP Suppresses SLC7A1 Degradation to Regulate Hepatoblastoma Progression. Mol Ther Oncolytics. 2020 Oct 4;19:149-162. [Content Brief]
- [3]. Wang Y, et al. Integrative Multi-Omics Analysis and Experimental Validation Identify SPOP as a Prognostic Biomarker and Immune Regulator in Lung Adenocarcinoma. J Cancer. 2025 Jun 23;16(9):2984-2996. [Content Brief]
- [4]. Diop A, et al. Biophysical Characterization of the Binding Mechanism between the MATH Domain of SPOP and Its Physiological Partners. Int J Mol Sci. 2023 Jun 14;24(12):10138. [Content Brief]
- [5]. Burleson M, et al. GLI3 Is Stabilized by SPOP Mutations and Promotes Castration Resistance via Functional Cooperation with Androgen Receptor in Prostate Cancer. Mol Cancer Res. 2022 Jan;20(1):62-76. [Content Brief]
- [6]. Meng F, et al. Drug design targeting active posttranslational modification protein isoforms. Med Res Rev. 2021 May;41(3):1701-1750. [Content Brief]
