title: Identification of factors that function in Drosophila salivary gland cell death during development using proteomics.
abstract: Proteasome inhibitors induce cell death and are used in cancer therapy, but little is known about the relationship between proteasome impairment and cell death under normal physiological conditions. Here, we investigate the relationship between proteasome function and larval salivary gland cell death during development in Drosophila. Drosophila larval salivary gland cells undergo synchronized programmed cell death requiring both caspases and autophagy (Atg) genes during development. Here, we show that ubiquitin proteasome system (UPS) function is reduced during normal salivary gland cell death, and that ectopic proteasome impairment in salivary gland cells leads to early DNA fragmentation and salivary gland condensation in vivo. Shotgun proteomic analyses of purified dying salivary glands identified the UPS as the top category of proteins enriched, suggesting a possible compensatory induction of these factors to maintain proteolysis during cell death. We compared the proteome following ectopic proteasome impairment to the proteome during developmental cell death in salivary gland cells. Proteins that were enriched in both populations of cells were screened for their function in salivary gland degradation using RNAi knockdown. We identified several factors, including trol, a novel gene CG11880, and the cop9 signalsome component cop9 signalsome 6, as required for Drosophila larval salivary gland degradation.
authors.affiliation: Department of Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: C K
authors.initials: CK
authors.lastname: McPhee
authors.forename: B M
authors.initials: BM
authors.lastname: Balgley
authors.forename: C
authors.initials: C
authors.lastname: Nelson
authors.forename: J H
authors.initials: JH
authors.lastname: Hill
authors.forename: Y
authors.initials: Y
authors.lastname: Batlevi
authors.forename: X
authors.initials: X
authors.lastname: Fang
authors.forename: C S
authors.initials: CS
authors.lastname: Lee
authors.forename: E H
authors.initials: EH
authors.lastname: Baehrecke
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D000075686:COP9 Signalosome Complex; D053938:DNA Fragmentation; D004330:Drosophila / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism*; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000378:metabolism; D046912:Multiprotein Complexes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D020543:Proteome / Q000378:metabolism; D040901:Proteomics; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D012469:Salivary Glands / Q000166:cytology / Q000378:metabolism*; D014452:Ubiquitins / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D019812:Heparan Sulfate Proteoglycans; D046912:Multiprotein Complexes; D020543:Proteome; D034741:RNA, Small Interfering; D014452:Ubiquitins; C472788:trol protein, Drosophila; D010447:Peptide Hydrolases; D000075686:COP9 Signalosome Complex; D046988:Proteasome Endopeptidase Complex