(d) HeLa cells stably interfered for AMBRA1 were transiently transfected with empty vector or AMBRA1 vector; AMBRA1, ULK1, ATG13, p-ATG13 and actin levels were analysed by western blotting. Quantification of ULK1 and pATG13 bands is shown on the right. n = 3 extracts prepared from independent experiments. Data are presented as means±s.d. and significance is P = 0.006 for ULK1 and P = 0.044 and P = 0.011 for pATG13. 