ATAD5 functions as a regulatory platform for Ub-PCNA deubiquitination
Eunjin Ryu1,2, Juyeong Yoo1,2, Mi-Sun Kang1
1Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea.
Abstract:
Ubiquitination status of proliferating cell nuclear antigen (PCNA) is crucial for regulating DNA lesion bypass. After the resolution of fork stalling, PCNA is subsequently deubiquitinated, but the underlying mechanism remains undefined. We found that the N-terminal domain of ATAD5 (ATAD5-N), the largest subunit of the PCNA-unloading complex, functions as a scaffold for Ub-PCNA deubiquitination. ATAD5 recognizes DNA-loaded Ub-PCNA through distinct DNA-binding and PCNA-binding motifs. Furthermore, ATAD5 forms a heterotrimeric complex with UAF1-USP1 deubiquitinase, facilitating the deubiquitination of DNA-loaded Ub-PCNA. ATAD5 also enhances the Ub-PCNA deubiquitination by USP7 and USP11 through specific interactions. ATAD5 promotes the distinct deubiquitination process of UAF1-USP1, USP7, and USP11 for poly-Ub-PCNA. Additionally, ATAD5 mutants deficient in UAF1-binding had increased sensitivity to DNA-damaging agents. Our results ultimately reveal that ATAD5 and USPs cooperate to efficiently deubiquitinate Ub-PCNA prior to its release from the DNA in order to safely deactivate the DNA repair process.
Insights
ATAD5 acts as a scaffold to recruit deubiquitinases, enabling the removal of ubiquitin from proliferating cell nuclear antigen (PCNA). This process is essential for safely deactivating DNA repair pathways after DNA damage.
Area of Science:
- Molecular Biology
- DNA Repair Mechanisms
- Ubiquitin-Proteasome System
Background:
- Proliferating cell nuclear antigen (PCNA) ubiquitination is vital for DNA lesion bypass.
- The mechanism of PCNA deubiquitination after DNA fork stalling resolution is not well understood.
Purpose of the Study:
- To elucidate the mechanism of PCNA deubiquitination.
- To identify the factors involved in removing ubiquitin from PCNA.
Main Methods:
- Investigated the role of ATAD5 in PCNA deubiquitination.
- Utilized biochemical assays to study protein-protein interactions and deubiquitination activity.
- Analyzed ATAD5 mutants for sensitivity to DNA-damaging agents.
Main Results:
- The N-terminal domain of ATAD5 (ATAD5-N) functions as a scaffold for Ub-PCNA deubiquitination.
- ATAD5 recognizes DNA-loaded Ub-PCNA via specific DNA-binding and PCNA-binding motifs.
- ATAD5 forms a complex with UAF1-USP1 and enhances deubiquitination by USP7 and USP11.
- ATAD5 mutants lacking UAF1-binding show increased sensitivity to DNA-damaging agents.
Conclusions:
- ATAD5 and USP deubiquitinases cooperate to remove ubiquitin from PCNA.
- This coordinated action is critical for PCNA release from DNA and safe deactivation of DNA repair.
- ATAD5 is a key regulator in the PCNA deubiquitination pathway.
More Related Videos
Related Concept Videos
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein....
The Unfolded Protein Response
Export of Misfolded Proteins out of the ER


