Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2022 May 17;50(10):5635–5651. doi: 10.1093/nar/gkac375

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2022. Published by Oxford University Press on behalf of Nucleic Acids Research.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

PMC Copyright notice

Figure 4. — The kinase activity of DNA-PK_cs promotes the accumulation of RECQL4 at DSBs. (A) Inhibition of DNA-PK_cs attenuates accumulation of RECQL4 at laser-induced DSBs. U2OS RECQL4 Knockout cells stably expressing GFP-tagged RECQL4 were pretreated either with DMSO or 10 μM NU7441 for 2 h, and subsequently laser micro-irradiation assays were performed. Relative fluorescent intensity of GFP-tagged RECQL4 following micro-irradiation are presented as mean ± standard error of the mean (SEM). Samples analyzed were 15 for DMSO-treated and 16 NU7441-treated cells. Student's t-test (two-sided) was performed to assess statistical significance (*** P< 0.001). (B) Inhibition of DNA-PK_cs reduces the recruitment of RECQL4 to the chromatin fraction following IR. U2OS cells were pretreated with 10 μM NU7441 or DMSO for 2 h, mock-treated or irradiated with a dose of 10 Gy, and allowed to recover for 10 min. Subsequently, cytoplasmic, soluble nuclear and chromatin fractions were isolated for immunoblotting to examine the recruitment of proteins listed in the figure to the chromatin after irradiation. (C) Accumulation of GFP-tagged RECQL4 in HCT116 DNA-PK_cs kinase-dead (KD/–) cells is reduced compared to that in control DNA-PK_cs^+/– cells (+/–). Relative fluorescent intensity of GFP-tagged RECQL4 following micro-irradiation are presented as mean ± standard error of the mean (SEM). Samples analyzed were 8 for +/– and 8 for KD/– cells. Student's t-test (two-sided) was performed to assess statistical significance (*** P< 0.001). (D) Recruitment of RECQL4 to the chromatin fraction is decreased in KD/– cells compared to +/– cells. KD/– and +/– cells were mock-treated or irradiated with a dose of 10 Gy and allowed to recover for 10 minutes. Subsequently, cytoplasmic, soluble nuclear and chromatin fractions were isolated for immunoblotting to examine the recruitment of proteins listed in the figure to the chromatin after irradiation.