Autophagy under construction: insights from in vitro reconstitution of autophagosome nucleation.

Macroautophagy/autophagy is a complex process that involves over 40 proteins in Saccharomyces cerevisiae. How these proteins are organized, and their activities orchestrated to facilitate an efficient autophagic mechanism remain elusive. Sawa-Makarsha et al. reconstitute the initial steps of autophagosome biogenesis during selective autophagy using autophagy factors purified from yeast. Their results show that Atg9 vesicles serve as platforms for the recruitment of the autophagy machinery, and establish membrane contact sites to initiate lipid transfer for autophagosome biogenesis.Abbreviations: GUV, giant unilamellar vesicles; PAS, phagophore assembly site; PL, proteolipisomes.