Evolution of KIPPIS as a versatile platform for evaluating intracellularly functional peptide aptamers

Sci Rep. 2021 Jun 3;11(1):11758. doi: 10.1038/s41598-021-91287-z.

Abstract

Chimeric proteins have been widely used to evaluate intracellular protein-protein interactions (PPIs) in living cells with various readouts. By combining an interleukin-3-dependent murine cells and chimeric proteins containing a receptor tyrosine kinase c-kit, we previously established a c-kit-based PPI screening (KIPPIS) system to evaluate and select protein binders. In the KIPPIS components, proteins of interest are connected with a chemically inducible helper module and the intracellular domain of the growth-signaling receptor c-kit, which detects PPIs based on cell proliferation as a readout. In this system, proteins of interest can be incorporated into chimeric proteins without any scaffold proteins, which would be advantageous for evaluating interaction between small peptides/domains. To prove this superiority, we apply KIPPIS to 6 peptide aptamer-polypeptide pairs, which are derived from endogenous, synthetic, and viral proteins. Consequently, all of the 6 peptide aptamer-polypeptide interactions are successfully detected by cell proliferation. The detection sensitivity can be modulated in a helper ligand-dependent manner. The assay results of KIPPIS correlate with the activation levels of Src, which is located downstream of c-kit-mediated signal transduction. Control experiments reveal that KIPPIS clearly discriminates interacting aptamers from non-interacting ones. Thus, KIPPIS proves to be a versatile platform for evaluating the binding properties of peptide aptamers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Peptide / chemistry
  • Aptamers, Peptide / metabolism*
  • Humans
  • Ligands
  • Peptides / chemistry
  • Peptides / metabolism
  • Protein Binding
  • Protein Engineering / methods
  • Protein Interaction Mapping / methods*
  • Proto-Oncogene Proteins c-kit / chemistry
  • Proto-Oncogene Proteins c-kit / metabolism*

Substances

  • Aptamers, Peptide
  • Ligands
  • Peptides
  • Proto-Oncogene Proteins c-kit