After publication of this work [1], we noted that we inadvertently failed to include the complete list of all coauthors. The full list of authors has now been added and the Authors’ contributions and Competing interests section modified accordingly.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
JL and JW conceived and designed the experiments. MW, LW, QL and PK performed the experiments. MW, LW, QL, PK, JL, JQ and JW analyzed the data. JW wrote the paper. All authors read and approved the final manuscript.