GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:17079271

From GONUTS
Jump to: navigation, search
Citation

Vereshchagina, N and Wilson, C (2006) Cytoplasmic activated protein kinase Akt regulates lipid-droplet accumulation in Drosophila nurse cells. Development 133:4731-5

Abstract

The insulin/insulin-like growth factor signalling (IIS) cascade performs a broad range of evolutionarily conserved functions, including the regulation of growth, developmental timing and lifespan, and the control of sugar, protein and lipid metabolism. Recently, these functions have been genetically dissected in the fruit fly Drosophila melanogaster, revealing a crucial role for cell-surface activation of the downstream effector kinase Akt in many of these processes. However, the mechanisms regulating lipid metabolism and the storage of lipid during development are less well characterized. Here, we use the nutrient-storing nurse cells of the fly ovary to study the cellular effects of intracellular IIS components on lipid accumulation. These cells normally store lipid in a perinuclear pool of small neutral triglyceride-containing droplets. We find that loss of the IIS signalling antagonist PTEN, which stimulates cell growth in most developing tissues, produces a very different phenotype in nurse cells, inducing formation of highly enlarged lipid droplets. Furthermore, we show that the accumulation of activated Akt in the cytoplasm is responsible for this phenotype and leads to a much higher expression of LSD2, the fly homologue of the vertebrate lipid-storage protein perilipin. Our work therefore reveals a signalling mechanism by which the effect of insulin on lipid metabolism could be regulated independently of some of its other functions during development and adulthood. We speculate that this mechanism could be important in explaining the well-established link between obesity and insulin resistance that is observed in Type 2 diabetes.

Links

PubMed Online version:10.1242/dev.02659

Keywords

Animals; Animals, Genetically Modified; Drosophila Proteins/genetics; Drosophila Proteins/metabolism; Drosophila melanogaster/cytology; Drosophila melanogaster/genetics; Drosophila melanogaster/growth & development; Drosophila melanogaster/metabolism; Female; Genes, Insect; Insulin/metabolism; Lipid Metabolism; Models, Biological; Mutation; Ovary/cytology; Ovary/metabolism; PTEN Phosphohydrolase/genetics; PTEN Phosphohydrolase/metabolism; Proto-Oncogene Proteins c-akt/metabolism; Signal Transduction; Somatomedins/metabolism

Significance

Annotations

Gene product Qualifier GO ID GO term name Evidence Code with/from Aspect Notes Status


See also

References

See Help:References for how to manage references in GONUTS.