This article has been retracted at the request of the editors.
Molecular Cell is retracting this article. In response to concerns raised by a reader, we contacted the corresponding author for original data and investigated the issues. The Research Integrity Office at Saint Louis University also investigated the matter. Both investigations determined that data in two figures had been inappropriately manipulated. In Figure 4A, a section from one part of the image was duplicated and placed over another part of the image. In this instance the authors could not locate the original data; thus we cannot determine whether the alteration obscured any relevant, underlying data. In Figure 5B there is a splice between lanes 2 and 3. While the splice in itself does not necessarily indicate inappropriate manipulation, the investigations found that what is depicted in lane 3 is not what appears in the original data image. Additionally, in Figure 5B, one of the lanes (labeled “alphas”) was inappropriately manipulated to remove blemishes. Given these issues, we are retracting the paper. The authors do not agree to the Retraction.