There was an error published in J. Cell Sci. 122, 727-735.

The affiliation of Vladimir A. Lizunov was incorrect in the original version of this paper. The correct affiliation details of all authors are shown above.

The authors also wish to acknowledge that the research was supported in part by the Intramural Research Program of the NIH, NIDDK and NICHD.

The authors apologise for these mistakes.