Figure 4
From: Rational design of phase separating peptides based on phase separating protein sequence of p53
Size-dependent uptake of p53 oligomers into designed peptide droplets and enhanced uptake of high-order oligomers upon elongation of the linker. (A) Fluorescence images of Alexa488-labeled p53 oligomers and Alexa488 in non-labeled designed peptide droplet solution. The solution contained designed peptides with the concentration range of 0.9–1.8 mM and 0.1 µM of labeled p53 oligomers or Alexa488 in the absence of salt at pH 7.0. (B) Enrichment index of Alexa488-labeled p53 oligomers and Alexa488 in the designed peptide droplets. Error bars denote the standard errors. (C) Proposed models of size-dependent uptake of p53 oligomers into the droplets of two representative designed peptides with GSGS- and (GGGS)3-linkers. The droplet (dashed grey circle) is formed by designed peptides (grey). As shown in the left panel, uptake of p53 dimer and tetramer was limited compared to that of p53 monomer, likely owing to the small droplet voids of GSGS-linker peptides. As shown in the middle panel, p53 tetramers may be localized onto the droplet surface due to their exclusion from droplets and interaction between designed peptides and p53. As shown in the right panel, the uptake of p53 dimer and tetramer into (GGGS)3-linker peptide droplets was enhanced since the linker elongation seemed to increase droplet voids. Solid and dashed arrows represent the major and minor events for the uptake inside the droplets or the localization on droplet surfaces, respectively. Red, green, black, yellow, and blue represent N-terminal IDR, core domain, linker, tetramerization domain, and C-terminal IDR of p53, respectively.
