How a RING finger protein and a steroid hormone control autophagy

Autophagy. 2006 Oct-Dec;2(4):321-2. doi: 10.4161/auto.3091. Epub 2006 Oct 14.

Abstract

Previous work in our laboratory has indicated that the steroid hormone ecdysone triggers programmed autophagy in the fat body of Drosophila larvae by downregulating the class I phosphoinositide 3-kinase (PI3K) pathway. We recently found evidence that Deep orange (Dor), a Drosophila RING finger protein implicated in late-endosomal trafficking, controls ecdysone signaling as well as autolysosome fusion, thus exerting a dual regulation of autophagy. We found that dor mutants are defective in programmed autophagy. The mutant larvae showed impaired upregulation of ecdysone signaling during development, accompanied by a failure to downregulate the PI3K pathway. Downregulation of the PI3K pathway could be restored by feeding the dor mutants with ecdysone. Even though ecdysone signaling and autophagy were impaired in the dor mutants, we detected an accumulation of autophagosomes in dor mutant fat bodies. This could probably be attributed to the failure of autophagosomes to fuse with lysosomes. In this Addendum we review these findings and provide some speculations about how Dor may control both ecdysone signalling and autolysosomal fusion.

Publication types

  • Review

MeSH terms

  • Animals
  • Autophagy / physiology*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / physiology*
  • Ecdysone / metabolism*
  • Gene Expression Regulation, Developmental
  • Insect Proteins / genetics
  • Insect Proteins / metabolism
  • Larva / anatomy & histology
  • Larva / physiology
  • Lysosomes / metabolism
  • Signal Transduction / physiology*
  • Zinc Fingers

Substances

  • DNA-Binding Proteins
  • DOR protein, Drosophila
  • Drosophila Proteins
  • Insect Proteins
  • Ecdysone