VOLUME 286 (2011) PAGES 15440–15457
This article has been withdrawn by the authors. After reviewing the data, the corresponding author learned that there was duplication of data in Figs. 1A, 2D, 4A, 5, 6, 8C, 8D, S4F, and S4G. The authors wish to withdraw the article in the interests of maintaining their publication standards, while also respecting the highest standards of transparency and reliability of their research and of the JBC. Replica data sets for each of the figures in question that the authors state fully validate the findings and conclusions of the published article are available. A revised version of the manuscript with those replica data sets can be obtained by contacting the corresponding author.