Nature 446, 690–694 (2007)

It has come to our attention that some of the control lanes in Fig. 2a (Kai1 and Mkk4 control lanes) may have been inadvertently duplicated during figure assembly; the other control lanes and the experimental Maspin lanes are correct. We have therefore repeated the experiments and obtained the same results as those in the published figure. The primary data from this experiment can be found in Supplementary Information.