Cell-Based Biosensors Based on Intein-Mediated Protein Engineering for Detection of Biologically Active Signaling Molecules

Anal Chem. 2018 Aug 21;90(16):9779-9786. doi: 10.1021/acs.analchem.8b01481. Epub 2018 Aug 3.

Abstract

Live-cell-based biosensors have emerged as a useful tool for biotechnology and chemical biology. Genetically encoded sensor cells often use bimolecular fluorescence complementation or fluorescence resonance energy transfer to build a reporter unit that suffers from nonspecific signal activation at high concentrations. Here, we designed genetically encoded sensor cells that can report the presence of biologically active molecules via fluorescence-translocation based on split intein-mediated conditional protein trans-splicing (PTS) and conditional protein trans-cleavage (PTC) reactions. In this work, the target molecules or the external stimuli activated intein-mediated reactions, which resulted in activation of the fluorophore-conjugated signal peptide. This approach fully valued the bond-making and bond-breaking features of intein-mediated reactions in sensor construction and thus eliminated the interference of false-positive signals resulting from the mere binding of fragmented reporters. We could also avoid the necessity of designing split reporters to refold into active structures upon reconstitution. These live-cell-based sensors were able to detect biologically active signaling molecules, such as Ca2+ and cortisol, as well as relevant biological stimuli, such as histamine-induced Ca2+ stimuli and the glucocorticoid receptor agonist, dexamethasone. These live-cell-based sensing systems hold large potential for applications such as drug screening and toxicology studies, which require functional information about targets.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Biosensing Techniques / methods*
  • Calcium / analysis*
  • Calmodulin / genetics
  • Cell Engineering / methods
  • Exteins / genetics
  • Exteins / physiology
  • HeLa Cells
  • Hormones / analysis*
  • Humans
  • Inteins / genetics
  • Inteins / physiology*
  • Luminescent Proteins / chemistry
  • Luminescent Proteins / genetics
  • Protein Engineering / methods
  • Protein Sorting Signals / genetics
  • Protein Splicing*
  • Red Fluorescent Protein

Substances

  • Calmodulin
  • Hormones
  • Luminescent Proteins
  • Protein Sorting Signals
  • Calcium