Jiefei Geng and Daniel J. Klionsky

Jiefei Geng

Daniel J. Klionsky

Corresponding author: klionsky@umich.edu
Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, and Department of Biological Chemistry; University of Michigan; Ann Arbor, MI USA

In macroautophagy (hereafter autophagy), a morphological hallmark is the formation of double-membrane vesicles called autophagosomes that sequester and deliver cytoplasmic components to the lysosome/vacuole for degradation. This process begins with an initial sequestering compartment, the phagophore, which expands into the mature autophagosome. A tremendous amount of work has been carried out to elucidate the mechanism of how the autophagosome is formed. However, an important missing piece in this puzzle is where the membrane comes from. Independent lines of evidence have shown that pre-existing organelles may continuously supply lipids to support autophagosome formation. In our analysis, we identified several components of the late stage secretory pathway that may redirect Golgi-derived membrane to autophagosome formation in response to starvation conditions.

Punctum to: Geng J, Nair U, Yasumura-Yorimitsu K, Klionsky DJ. Post-Golgi Sec2 proteins are required for autophagy in Saccharomyces cerevisiae. Mol Biol Cell 2010; 21:2257-69; PMID: 20444978; DOI: 10.1091/mbc.E09-11-0969.
PMID: 20444978 DOI: 10.1091/mbc.E09-11-0