Journal: bioRxiv
Article Title: Internal Translation of p53 Oncoproteins During Integrated Stress Response Confers Survival Advantage on Cancer Cells
doi: 10.1101/2023.03.03.531004
Figure Lengend Snippet: a , Western blot analyses (WB) of H1299 cells expressing Δ133p53 and treated with DMSO (-) or with ISR activator thapsigargin (Th, 16h) and proteasome inhibitor (MG132, 4h) or translation inhibitor (cycloheximide, CHX, 4h). b , Likelihood of translation initiation from start codons homologous to human TIS (hTIS) 1, 40, 133 and 160 in 6 different mammalian species, as predicted by NetStart 1.0 (top) and ATGpr (bottom). c, d , WB of H1299 cells expressing 5’cap-translation–blocking bicistronic mRNA containing Δ160p53 and its 5’UTR (b-5’Δ160, represented in ( c ), top panel) and treated with DMSO (-) or Th (16h) as indicated. A549 cells endogenously expressing p53 were also analysed for comparison ( c ). P-eIF2α, phosphorylated eIF2α (ISR marker). e , WB of H1299 cells expressing bicistronic Δ133p53 mRNA (b-Δ133) and treated with DMSO (-, 36h), Th (16h) or DNA damaging drug etoposide (Eto, 36h). f , WB of H1299 cells expressing tagged and mutated p53, as indicated, and treated with Th (16h). fs indicates frameshift mutations of one nucleotide at the indicated codon (157 or 130). g-j , Luminescence readings (% increase of Firefly Luciferase / Renilla Luciferase ratio over empty control) of A549, H1299, HCT116 or HeLa cells expressing empty bicistronic dual-luciferase mRNA (b-Luc, represented in ( g )) or b-Luc mRNAs containing the first 432 or 258 nucleotides of Δ160p53 (b-Δ160(432) Luc or b-Δ160(258) Luc, respectively) or 78 nucleotides of the 5’-UTR of Δ160p53 (b-Δ160’s 5’UTR(78) Luc) or the positive control c-myc IRES (b-c-mycIRES Luc), as indicated, and treated or not with Th (16h). Shown are averages ± s.d. of n experiments as indicated or representative data of at least three independent experiments (* P < 0.05, **P < 0.01 and ***P < 0.005 compared to negative control). CM1, polyclonal anti-p53 antibody. The numbers in parenthesis under the WBs specify the amounts of protein for the indicated bands relative to bands showing numbers in bold, according to WB quantifications and normalization against α-tubulin.
Article Snippet: Primary antibodies used for WB were CM-1, Bp53.10, DO12 and MAP4 for p53 isoforms, anti-α-tubulin (Calbiochem DM1A), anti-Flag (Sigma M2), anti-Flag (BioLegend L5), anti-HA (Roche 3F10), anti-Lamin B1 (Santa Cruz Biotechnology A-11), anti-vinculin (Santa Cruz Biotechnology H-10), anti-Phospho-eIF2α (Ser51) (Cell Signaling Technology).
Techniques: Western Blot, Expressing, Blocking Assay, Comparison, Marker, Luciferase, Control, Positive Control, Negative Control