Scientific Reports 5: Article number: 12210; published online: 20 July 2015; updated: 30 October 2015

Marlies A. Lambrecht was omitted from the author list in the original version of this Article.

This has been corrected in the PDF and HTML versions of the Article.

The Author Contributions section now reads:

Conceived and designed the experiments: I.R. and B.L. Conducted the experiments: I.R., B.L., K.A.S., M.A.L. Analyzed the results: I.R. Contributed reagents/materials/analysis tools: P.K. and J.A.D. Wrote the paper: I.R. Reviewed the manuscript: I.R., B.L., K.A.S., P.K. and J.A.D.