RETRACTION
The publisher hereby retracts the manuscript posted on MCB Accepts as doi: 10.1128/MCB.01170-13. After the manuscript was published online, this article was found to have multiple images that were unacceptably manipulated or duplicated (Fig. 1A, 2A, and 3A, B, and F). Since the integrity of the data as presented was compromised, this publication is retracted in its entirety. We apologize to the readers of Molecular and Cellular Biology and regret any inconvenience that this causes.