Alexa fluor 488 goat anti mouse ab150117

All cell lines were cultured in DMEM medium with 10% fetal bovine serum, 100 U/ml penicillin and 100 mg/ml streptomycin (Millipore-Sigma) in a humidified incubator with 5% CO₂ at 37 °C.
Initial experiments were performed on primary MEFs derived from 13.5 days NM1 WT and KO embryos^{46 (link)}. In other experiments were used immortalized MEFs (ATCC® CRL-2752) or cell lines derived from these immortalized cells.
The antibodies against H3K9me3 (ab8898), H3K27ac (ab4729), H3K4me1 (ab8895), H3K4me3 (ab8580), H3K9ac (ab10812), H3 (ab1791), γH2AX (ab2893), p53-K370 (ab183544), PCAF (ab12188), Set1 (ab70378), GAPDH (ab8245), and nonspecific rabbit IgG isotype control (ab37415) were purchased from Abcam (Cambridge, MA, USA). The antibody against NM1 has been previously characterized^{2 (link)}. Alexa Fluor 555 Goat Anti-Rabbit (ab150078) and Alexa Fluor 488 Goat Anti-Mouse (ab150117) were used as secondary antibodies for immunofluorescence, and horseradish peroxidase (HRP)-fused Goat Anti-Rabbit (ab6721) and Rabbit Anti-Mouse (ab6728) secondary antibodies for western blottings were purchased from Abcam. Hoechst 43222 (H1399) and ProLong Gold Antifade Mountant with 4′,6-diamidino-2-phenylindole (DAPI; P36931) were purchased from Invitrogen, Waltham, MA, USA. All antibodies have been used according to the manufacturers’ protocols.

HeLa cells (ATCC^® CCL-2) were cultured in DMEM with high glucose, 10% fetal bovine serum, 100 U/mL penicillin and 100 mg/mL streptomycin (all from Millipore-Sigma, Burlington, MA, USA), in a humidified incubator with 5% CO₂ at 37 °C. For peptide treatment, 5 × 10⁵ cells were seeded in 6-well plates with 2 mL of full-DMEM medium 24 h before the treatment. Next day, the medium was exchanged with pre-warmed DMEM medium supplemented with respective peptides and incubated for defined times. As a negative control, HeLa cells were incubated with pre-warmed DMEM medium supplemented with 1× PBS without any of the CPPs.
Antibodies against fibrillarin (ab4566), coilin (ab87913), Sc35 (ab11826), tubulin (ab195883), 58K (ab27043) and M6PR (ab124767) were all purchased from Abcam (Cambridge, MA, USA). Alexa Fluor 555 Goat Anti-Rabbit (ab150078) and Alexa Fluor 488 Goat Anti-Mouse (ab150117), used as secondary antibodies, were also purchased from Abcam. Hoechst 43222 (H1399) were purchased from Invitrogen (Waltham, MA, USA).

Cryosections of mouse eyes were fixed by 1% paraformaldehyde (PFA, Electron Microscopy Sciences, Hatfield, PA, USA) for 15 min at room temperature, washed in phosphate buffered saline (PBS, Sigma Aldrich, Meick KGaA, Darmstadt, Germany) 4 times, and incubated in blocking buffer (PBS containing 10% goat serum (Sigma Aldrich, Meick KGaA, Darmstadt, Germany), 1% bovine serum albumin (BSA, Thermo Fisher Scientific, Waltham, MA, USA), and 0.4% Triton X-100 (Sigma Aldrich, Meick KGaA, Darmstadt, Germany) for 1 h at room temperature. The cells were incubated with primary antibody (K14: MA5-11599, 1:500 dilution, Thermo Fisher Scientific, Waltham, MA, USA; p63: 13109S, 1:200 dilution, Cell Signaling Technology, Danvers, MA, USA) in blocking buffer for 2 h at room temperature. Excess antibody with non-specific binding was washed away by PBST (PBS containing 0.025% Triton X-100). Secondary antibodies (Alexa Fluor 488 goat anti mouse, ab150117, 1:1000 dilution, Abcam, Cambridge, MA, USA; Alexa Fluor 555 goat anti rabbit, A21428, 1:1000 dilution, Thermo Fisher, Waltham, MA, USA) were used in blocking buffer for 1h at room temperature, followed by PBST wash 3 times. Nuclei were counterstained by Hoechst 33342 (3570, Thermo Fisher Scientific, Inc., Waltham, MA, USA). Images were taken by Olympus IX81 (Olympus, Center Valley, PA, USA).