Fig. 1: Detection of an active 4EBP1/2 pool under basal conditions. | Cell Death & Disease

Fig. 1: Detection of an active 4EBP1/2 pool under basal conditions.

From: 4EBP1/2 are active under standard cell culture conditions to regulate the translation of specific mRNAs

Fig. 1

a The indicated cells were grown in normal cell culture media, treated or not with 1 μM of the mTOR inhibitor KU-0063794 (KU) for 4h, were lysed and incubated with m7GTP coated beads. When indicated, cell lysates were pre-incubated with free m7GTP (shSCR+m7GTP) to detect nonspecific binding. Eluted and total proteins were analyzed by immunoblot using the indicated antibodies. Protein levels of m7GTP bound eIF4G and eIF4E were quantified using ImageJ and presented in a bar graph; *p < 0.05. b Scheme of the bicistronic Luciferase reporter; Rluc is driven by cap-dependent mRNA translation through an artificial 5′UTR, Fluc is produced by cap-independent mRNA translation through a poliovirus IRES (POLIRES). HEK293 shSCR and sh4EBPs transfected with pcDNA3-RLUC-POLIRES-FLUC bicistronic vector were grown in normal media. 24h post-transfection, cells were lysed and levels of Rluc and Fluc were sequentially measured. Results are expressed as Rluc/FLuc ratio (n = 3 biologically independent experiments). Data are reported as means ± SD with indicated significance (*p < 0.05). c HEK293 shSCR and sh4EBPs cells were lysed, separated on non-linear sucrose gradients and polysome profiles were generated by measuring absorbance at 260 nm. Polysomal fractions, highlighted in grey, were collected together with total mRNA. mRNA was then extracted and sequenced. Heat map representation of transcripts whose TE is significantly different between the HEK293 shSCR and sh4EBPs cells, highlighting the three biological replicates.

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