In the version of the article initially published, the genetic background labels at the top of Fig. 5f and g were mistakenly deleted during production and have now been reinstated; in the grey section of Fig. 5h, the second from left label was “PtdIns3P (3,4,5)P 3 ” but should have been “PtdIns3P”, the second from right label was “PtdIns3P (3,5)P 2 ” but should have been “PtdIns (3,5)P 2 ”, and the far right label was “More PtdIns (3,4,5)P 3 ” but should have been “More PtdIns3P”. These corrections have been made to the HTML and PDF versions of the article.