Secretion of a recombinant protein without a signal peptide by the exocrine glands of transgenic rabbits

PLoS One. 2017 Oct 27;12(10):e0187214. doi: 10.1371/journal.pone.0187214. eCollection 2017.

Abstract

Transgenic rabbits carrying mammary gland specific gene constructs are extensively used for excreting recombinant proteins into the milk. Here, we report refined phenotyping of previously generated Venus transposon-carrying transgenic rabbits with particular emphasis on the secretion of the reporter protein by exocrine glands, such as mammary, salivary, tear and seminal glands. The Sleeping Beauty (SB) transposon transgenic construct contains the Venus fluorophore cDNA, but without a signal peptide for the secretory pathway, driven by the ubiquitous CAGGS (CAG) promoter. Despite the absence of a signal peptide, the fluorophore protein was readily detected in milk, tear, saliva and seminal fluids. The expression pattern was verified by Western blot analysis. Mammary gland epithelial cells of SB-CAG-Venus transgenic lactating does also showed Venus-specific expression by tissue histology and fluorescence microscopy. In summary, the SB-CAG-Venus transgenic rabbits secrete the recombinant protein by different glands. This finding has relevance not only for the understanding of the biological function of exocrine glands, but also for the design of constructs for expression of recombinant proteins in dairy animals.

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Exocrine Glands / metabolism*
  • Protein Sorting Signals*
  • Rabbits
  • Recombinant Proteins / metabolism

Substances

  • Protein Sorting Signals
  • Recombinant Proteins

Grants and funding

This work was supported by (OTKA) National Research, Development and Innovation Office (NKFIH) NN grant no. 108921 to ZB, grant no. PD 120870 to LN and grant no. NN 113162 to LH. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.