About the Authors
Department of Cell Biochemistry, University of Groningen, Haren, the Netherlands
The author has declared that no competing interests exist.
Conceived and designed the experiments: PJMVH. Performed the experiments: PJMVH. Analyzed the data: PJMVH. Contributed reagents/materials/analysis tools: PJMVH. Wrote the paper: PJMVH.