A Purified Truncated Form of Yeast Gal4 Expressed in Escherichia Coli and Used to Functionalize Poly(lactic Acid) Nanoparticle Surface Is Transcriptionally Active in Cellulo

Protein Expr Purif. 2015 Sep;113:94-101. doi: 10.1016/j.pep.2015.05.009. Epub 2015 May 19.


Gal4/UAS system is a powerful tool for the analysis of numerous biological processes. Gal4 is a large yeast transcription factor that activates genes including UAS sequences in their promoter. Here, we have synthesized a minimal form of Gal4 DNA sequence coding for the binding and dimerization regions, but also part of the transcriptional activation domain. This truncated Gal4 protein was expressed as inclusion bodies in Escherichia coli. A structured and active form of this recombinant protein was purified and used to cover poly(lactic acid) (PLA) nanoparticles. In cellulo, these Gal4-vehicles were able to activate the expression of a Green Fluorescent Protein (GFP) gene under the control of UAS sequences, demonstrating that the decorated Gal4 variant can be delivery into cells where it still retains its transcription factor capacities. Thus, we have produced in E. coli and purified a short active form of Gal4 that retains its functions at the surface of PLA-nanoparticles in cellular assay. These decorated Gal4-nanoparticles will be useful to decipher their tissue distribution and their potential after ingestion or injection in UAS-GFP recombinant animal models.

Keywords: Escherichia coli; Gal4; Inclusion bodies; PLA nanoparticle; UAS–Gal4 system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism*
  • Drosophila melanogaster / physiology
  • Escherichia coli / genetics*
  • Inclusion Bodies
  • Lactic Acid / chemistry
  • Lactic Acid / metabolism*
  • Nanoparticles / chemistry
  • Nanoparticles / metabolism*
  • Polyesters
  • Polymers / chemistry
  • Polymers / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / isolation & purification
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Surface Properties
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*


  • DNA-Binding Proteins
  • GAL4 protein, S cerevisiae
  • Polyesters
  • Polymers
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Lactic Acid
  • poly(lactide)