Rabbit Anti-Human WIPI2 Polyclonal antibody

The conserved Ser/Thr kinase Atg1/ULK1 plays a crucial role in the regulation of autophagy. However, only very few Atg1 targets have been identified, impeding elucidation of the mechanisms by which Atg1 regulates autophagy. In our study, we determined the Saccharomyces cerevisiae Atg1 consensus phosphorylation sequence using a peptide array-based approach. Among proteins containing this sequence we identified Atg9, another essential component of the autophagic machinery. We showed that phosphorylation of Atg9 by Atg1 is required for phagophore elongation, shedding light on the mechanism by which Atg1 regulates early steps of autophagy.

ISG15 is an interferon-stimulated, ubiquitin-like protein, with anti-viral and anti-bacterial activity. Here, we map the endogenous in vivo ISGylome in the liver following Listeria monocytogenes infection by combining murine models of reduced or enhanced ISGylation with quantitative proteomics. Our method identifies 930 ISG15 sites in 434 proteins and also detects changes in the host ubiquitylome. The ISGylated targets are enriched in proteins which alter cellular metabolic processes, including upstream modulators of the catabolic and antibacterial pathway of autophagy. Computational analysis of substrate structures reveals that a number of ISG15 modifications occur at catalytic sites or dimerization interfaces of enzymes. Finally, we demonstrate that animals and cells with enhanced ISGylation have increased basal and infection-induced autophagy through the modification of mTOR, WIPI2, AMBRA1, and RAB7. Taken together, these findings ascribe a role of ISGylation to temporally reprogram organismal metabolism following infection through direct modification of a subset of enzymes in the liver.