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Updated: Nov 12, 2025

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Published on: March 9, 2012
α-Arrestin ARRDC3 tumor suppressor function is linked to GPCR-induced TAZ activation and breast cancer metastasis
Aleena K S Arakaki1,2,3, Wen-An Pan1, Helen Wedegaertner1,2
1Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
Abstract:
The α-arrestin domain containing protein 3 (ARRDC3) is a tumor suppressor in triple-negative breast carcinoma (TNBC), a highly metastatic subtype of breast cancer that lacks targeted therapies. Thus, understanding the mechanisms and targets of ARRDC3 in TNBC is important. ARRDC3 regulates trafficking of protease-activated receptor 1 (PAR1, also known as F2R), a G-protein-coupled receptor (GPCR) implicated in breast cancer metastasis. Loss of ARRDC3 causes overexpression of PAR1 and aberrant signaling. Moreover, dysregulation of GPCR-induced Hippo signaling is associated with breast cancer progression. However, the mechanisms responsible for Hippo dysregulation remain unknown. Here, we report that the Hippo pathway transcriptional co-activator TAZ (also known as WWTR1) is the major effector of GPCR signaling and is required for TNBC migration and invasion. Additionally, ARRDC3 suppresses PAR1-induced Hippo signaling via sequestration of TAZ, which occurs independently of ARRDC3-regulated PAR1 trafficking. The ARRDC3 C-terminal PPXY motifs and TAZ WW domain are crucial for this interaction and are required for suppression of TNBC migration and lung metastasis in vivo. These studies are the first to demonstrate a role for ARRDC3 in regulating GPCR-induced TAZ activity in TNBC and reveal multi-faceted tumor suppressor functions of ARRDC3. This article has an associated First Person interview with the first author of the paper.
Insights
Alpha-arrestin domain containing protein 3 (ARRDC3) suppresses triple-negative breast cancer (TNBC) metastasis by sequestering TAZ, a key effector of G-protein-coupled receptor signaling. This interaction inhibits tumor cell migration and invasion, highlighting ARRDC3 as a potential therapeutic target.
Area of Science:
- Oncology
- Molecular Biology
- Cell Biology
Background:
- Triple-negative breast carcinoma (TNBC) is a highly metastatic breast cancer subtype lacking targeted therapies.
- Alpha-arrestin domain containing protein 3 (ARRDC3) acts as a tumor suppressor in TNBC.
- Dysregulation of G-protein-coupled receptor (GPCR) signaling and the Hippo pathway is linked to breast cancer progression.
Purpose of the Study:
- To elucidate the mechanisms by which ARRDC3 suppresses TNBC metastasis.
- To investigate the role of ARRDC3 in regulating GPCR-induced Hippo signaling.
- To identify the key molecular interactions underlying ARRDC3's tumor suppressor function.
Main Methods:
- Investigated the interaction between ARRDC3 and TAZ (WWTR1), a transcriptional co-activator of the Hippo pathway.
- Assessed the role of ARRDC3 in regulating protease-activated receptor 1 (PAR1) signaling.
- Utilized in vivo models to evaluate the impact of ARRDC3 on TNBC cell migration, invasion, and lung metastasis.
Main Results:
- TAZ is identified as a major effector of GPCR signaling required for TNBC migration and invasion.
- ARRDC3 suppresses PAR1-induced Hippo signaling by sequestering TAZ, independent of PAR1 trafficking.
- The interaction between ARRDC3's PPXY motifs and TAZ's WW domain is critical for suppressing TNBC metastasis in vivo.
Conclusions:
- ARRDC3 plays a multifaceted role in suppressing TNBC by regulating GPCR-induced TAZ activity.
- Targeting the ARRDC3-TAZ interaction presents a potential therapeutic strategy for TNBC.
- This study reveals novel mechanisms of tumor suppression by ARRDC3 in metastatic breast cancer.
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