Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2006-6-16
pubmed:abstractText
Lysosomal degradation of cytoplasm by way of autophagy is essential for cellular amino acid homeostasis and for tissue remodeling. In insects such as Drosophila, autophagy is developmentally upregulated in the larval fat body prior to metamorphosis. Here, autophagy is induced by the hormone ecdysone through down-regulation of the autophagy-suppressive phosphoinositide 3-kinase (PI3K) signaling pathway. In yeast, Vps18 and other members of the HOPS complex have been found essential for autophagic degradation. In Drosophila, the Vps18 homologue Deep orange (Dor) has previously been shown to mediate fusion of multivesicular endosomes with lysosomes. A requirement of Dor for ecdysone-mediated chromosome puffing has also been reported. In the present report, we have tested the hypothesis that Dor may control programmed autophagy at the level of ecdysone signaling as well as by mediating autophagosome-to-lysosome fusion. We show that dor mutants are defective in programmed autophagy and provide evidence that autophagy is blocked at two levels. First, PI3K activity was not down-regulated correctly in dor larvae, which correlated with a decrease in ecdysone reporter activity. The down-regulation of PI3K activity was restored by feeding ecdysone to the mutant larvae. Second, neither exogenous ecdysone nor overexpression of PTEN, a silencer of PI3K signaling, restored fusion of autophagosomes with lysosomes in the fat body of dor mutants. These results indicate that Dor controls autophagy indirectly, via ecdysone signaling, as well as directly, via autolysosomal fusion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0014-4827
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
312
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2018-27
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
A dual function for Deep orange in programmed autophagy in the Drosophila melanogaster fat body.
pubmed:affiliation
Department of Biochemistry, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't