Drosophila acinusencodes a novel regulator of endocytic and autophagic trafficking

Abstract

SUMMARYEndosomal trafficking affects many cellular pathways from cell signaling to metabolism, but little is known about how these effects are coordinated. In a genetic screen for mutants affecting endosomal trafficking, we identified Drosophila acinus (dacn; hook-like). Its mammalian homolog Acinus has been implicated in RNA processing and chromatin fragmentation during apoptosis. Loss-of-function analysis of dacn revealed two distinct functions. First, dacn is required for stabilization of early endosomes, thus modulating levels of Notch and Egfr signaling. Second, loss of dacn interferes with cellular starvation responses by inhibiting autophagosome maturation. By contrast, overexpression of dacn causes lethality due to enhanced autophagy. We show that this enhanced autophagy is independent of the Tor pathway. Taken together, our data show that dacn encodes a regulator of endosomal and autophagosomal dynamics, modulating developmental signaling and the cellular response to starvation.

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

“…1540,1541 Acinus: A protein that in Drosophila regulates both endocytosis and macroautophagy; the acn mutant is defective in autophagosome maturation, whereas stabilization of endogenous Acn by mutation of its caspase cleavage site, 1542 or overexpression of Acn leads to excessive macroautophagy. 1543 Note that Acn can also induce DNA condensation or fragmentation after its activation by CASP3 in apoptotic cells. ActA: A L. monocytogenes protein that recruits the Arp2/3 complex and other actin-associated components to the cell surface to evade recognition by xenophagy; this effect is independent of bacterial motility.…”

Rab11 facilitates cross-talk between autophagy and endosomal pathway through regulation of Hook localization

“…, 2000) and the Hook-like protein Acinus was described as an important regulator of endosome maturation and autophagic processes (Haberman et al. , 2010).…”

Transcriptome of Tetranychus urticae embryos reveals insights into Wolbachia‐induced cytoplasmic incompatibility

“…High expression of hid may cause drastic induction of programmed cell death resulting in embryonic mortality (Grether et al, 1995). Over-expression of Acinus in Drosophila was reported to be lethal owing to enhanced autophagy (Haberman et al, 2010). In addition, we noticed that two male-specific lethal (MSL) complex genes [maleless (LOC107368317) and msl-2 (LOC107366086)] were up-regulated specifically in CI embryos.…”