Work

USP7 Is a Suppressor of PCNA Ubiquitination and Oxidative-Stress-Induced Mutagenesis in Human Cells

Year: 2015

Type: article

Abstract: Mono-ubiquitinated PCNA activates error-prone DNA polymerases; therefore, strict regulation of PCNA mono-ubiquitination is crucial in avoiding undesired mutagenesis. In this study, we used an in vitro assay system to identify USP7 as a deubiquitinating enzyme of mono-ubiquitinated PCNA. Suppression of USP1, a previously identified PCNA deubiquitinase, or USP7 increased UV- and H2O2-induced PCNA mono-ubiquitination in a distinct and additive manner, suggesting that USP1 and USP7 make different contributions to PCNA deubiquitination in human cells. Cell-cycle-synchronization analyses revealed that USP7 suppression increased H2O2-induced PCNA ubiquitination throughout interphase, whereas USP1 suppression specifically increased ubiquitination in S-phase cells. UV-induced mutagenesis was elevated in USP1-suppressed cells, whereas H2O2-induced mutagenesis was elevated in USP7-suppressed cells. These results suggest that USP1 suppresses UV-induced mutations produced in a manner involving DNA replication, whereas USP7 suppresses H2O2-induced mutagenesis involving cell-cycle-independent processes such as DNA repair.

Source: Cell Reports

DOI: 10.1016/j.celrep.2015.11.014

Authors: Shu-ichiro Kashiwaba, Rie Kanao, Yuji Masuda, Rika Kusumoto-Matsuo, Fumio Hanaoka, Chikahide Masutani

Institutions: Research Institute of Environmental Medicine, Nagoya University, Nagoya University, Gakushuin University

Language: English

Topic: Ubiquitin and proteasome pathways

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $5,620