title: Smt3 is required for Drosophila melanogaster metamorphosis.
abstract: Sumoylation, the covalent attachment of the small ubiquitin-related modifier SUMO to target proteins, regulates different cellular processes, although its role in the control of development remains unclear. We studied the role of sumoylation during Drosophila development by using RNAi to reduce smt3 mRNA levels in specific tissues. smt3 knockdown in the prothoracic gland, which controls key developmental processes through the synthesis and release of ecdysteroids, caused a 4-fold prolongation of larval life and completely blocked the transition from larval to pupal stages. The reduced ecdysteroid titer of smt3 knockdown compared with wild-type larvae explains this phenotype. In fact, after dietary administration of exogenous 20-hydroxyecdysone, knockdown larvae formed pupal cases. The phenotype is not due to massive cell death or degeneration of the prothoracic glands at the time when puparium formation should occur. Knockdown cells show alterations in expression levels and/or the subcellular localisation of enzymes and transcription factors involved in the regulation of ecdysteroid synthesis. In addition, they present reduced intracellular channels and a reduced content of lipid droplets and cholesterol, which could explain the deficit in steroidogenesis. In summary, our study indicates that Smt3 is required for the ecdysteroid synthesis pathway at the time of puparium formation.
authors: Functional Genomics Unit, CIC bioGUNE, Technology Park, Building 801-A, 48160 DERIO, Bizkaia, Spain.
authors: Ana
authors: A
authors: Talamillo
authors: Jonatan
authors: J
authors: Sánchez
authors: Rafael
authors: R
authors: Cantera
authors: Coralia
authors: C
authors: Pérez
authors: David
authors: D
authors: Martín
authors: Eva
authors: E
authors: Caminero
authors: Rosa
authors: R
authors: Barrio
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002784:Cholesterol / Q000096:biosynthesis; D003593:Cytoplasm / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D004331:Drosophila melanogaster / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D026461:Ecdysteroids / Q000096:biosynthesis*; D004441:Ecdysterone / Q000494:pharmacology; D007814:Larva / Q000254:growth & development / Q000502:physiology; D008055:Lipids / Q000096:biosynthesis; D008675:Metamorphosis, Biological / Q000502:physiology; D011679:Pupa / Q000254:growth & development / Q000502:physiology; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D025841:Small Ubiquitin-Related Modifier Proteins
chemical_list: D029721:Drosophila Proteins; D026461:Ecdysteroids; D008055:Lipids; D012097:Repressor Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; C490960:smt3 protein, Drosophila; D004441:Ecdysterone; D002784:Cholesterol