(d) HeLa cells were co-transfected with vectors encoding for ubiquitin Lys-63-HA alone or in combination with AMBRA1. Protein extracts were immunoprecipitated using an anti-ULK1 antibody or with IgG as a negative control and Ub-Lys-63-HA, ULK1 and AMBRA1 were analysed by western blotting. 