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Published on: October 5, 2012
Ubiquitin-Specific Protease 49 Interacts with Bax to Modulate Apoptosis.
Hae-Seul Choi1, Soo-Yeon Kim2, So-Ra Kim2
1Department of Bioconvergence, Graduate School, CHA University, Seongnam 13488, Republic of Korea.
International Journal of Molecular Sciences
|May 13, 2026
Summary
Ubiquitin-specific protease 49 (USP49) deubiquitinates the apoptosis protein Bax, enhancing its mRNA levels and promoting cell death. USP49 regulates Bax via K29/K33/K63 linkages, not proteasomal degradation, acting as a stress-responsive apoptosis modulator.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Bax is a crucial protein in the Bcl-2 family, essential for initiating mitochondrial apoptosis.
- Understanding Bax regulation is key to controlling cell death pathways in diseases like cancer.
Purpose of the Study:
- To identify proteins interacting with Bax.
- To elucidate the functional role of ubiquitin-specific protease 49 (USP49) in Bax regulation and apoptosis.
Main Methods:
- Yeast two-hybrid screening to identify Bax-interacting proteins.
- Immunoprecipitation and GST pull-down assays to confirm protein interactions.
- Ubiquitination assays, RT-qPCR, and apoptosis assays to assess USP49 function.
Main Results:
- USP49 directly binds to Bax.
- USP49 reduces Bax polyubiquitination, particularly K11, K29, K33, and K63 linkages, without affecting K48-linked ubiquitination or protein stability.
- USP49 overexpression upregulates Bax mRNA levels, enhancing apoptosis, especially under DNA damage conditions.
Conclusions:
- USP49 regulates Bax through non-proteasomal ubiquitination (K29/K33/K63) and transcriptional upregulation.
- USP49 acts as a stress-responsive apoptosis modulator.
- USP49 is a potential therapeutic target for cancer treatment.
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