Journal: International journal of molecular sciences
Article Title: In and out of Replication Stress: PCNA/RPA1-Based Dynamics of Fork Stalling and Restart in the Same Cell.
doi: 10.3390/ijms26020667
Figure Lengend Snippet: Figure 4. Exchange of PCNA and RPA1 at replication foci during unperturbed and stalled replication. (A) Representative timelapse images depicting simultaneous FRAP of RPA1 and residual PCNA co-localized at stalled replication forks under nucleotide depletion. (B) Same as (A), but under conditions of ATR inhibition. (C) Replication timelapse images of PCNA FRAP at replication foci during unperturbed replication (upper panel) or in the presence of ATR inhibitor AZD6738. (D) FRAP curves of PCNA under the following conditions: untreated, HU alone, AZD alone, HU + AZD. The mean intensity is normalized as described in Figure S5. (E) Contribution of distinct PCNA fractions (freely diffusing [F1] and replisome-bound [F2]) to the FRAP curve under nucleotide depletion, as determined via fitting of two single exponential curves. (F) Same as (E), but in the presence of both AZD6738 and HU. (G) Recovery of the replisome-bound fraction of PCNA under HU treatment, as derived based on (E). (H) Recovery of the replisome-bound fraction of PCNA under HU treatment, as derived based on (F). (I) Comparison of PCNA recovery under the following conditions: untreated, AZD alone, HU alone, HU + AZD. The contribution of freely diffusing PCNA has been subtracted from the HU and HU + AZD curves, as per (G,H). (J) Number of PCNA complexes at a single replication fork, recovered after photobleaching. (K) Enlarged view of HU and HU + AZD curves from (J). (L) FRAP curves of RPA1 at replication foci under HU alone and HU + AZD. (M) Number of RPA complexes at a single replication fork recovered after photobleaching under HU alone and HU + AZD. For HU: n = 11 cells; for HU + AZD: n = 16 cells; for AZD (PCNA only): n = 13 cells; untreated (PCNA only): n = 15 cells. Abbreviations: HU: hydroxyurea; AZD: AZD6738.
Article Snippet: After blocking, membranes were incubated with mouse primary antibodies against PCNA (PC10) (sc-56, Santa Cruz Biotechnology, Dallas, TX, USA) and RPA70/RPA1 (MBS600132, MyBioSource, San Diego, CA, USA) overnight at 4 ◦C, followed by incubation with an IRDye® 800CW Goat anti-Mouse IgG Secondary Antibody (926-32210, LICORbio, Lincoln, NE, USA) at room temperature for 1 h. Bands were visualized using an Odyssey Infrared Imaging System (LICORbio) and saved as TIF images.
Techniques: Inhibition, Derivative Assay, Comparison