Matches in SemOpenAlex for { <https://semopenalex.org/work/W36155295> ?p ?o ?g. }
Showing items 1 to 71 of
71
with 100 items per page.
- W36155295 abstract "The molecular mechanism underlying circadian rhythms is conserved among organisms and consists of feedback loops where a transcriptional activating complex (the CLOCK (CLK)/CYCLE (CYC) heterodimer in Drosophila) drives the expression of the repressors of its activity (the period (per) and timeless (tim) genes and proteins in Drosophila). Importantly, the pace of the oscillator largely depends on post-transcriptional mechanisms that regulate the accumulation and activity of both the positive and negative components of the loop. A number of interacting partners that modify core clock components have already been isolated, but more are expected. Looking for new clock components, we set up a behavioral screen based on targeted expression of RNAi transgenes directed to half of the Drosophila genome. 54 putative new clock genes have been identified. Among them, some were independently reported to function within the fruit fly molecular clock, thus validating the screen. In this work, I investigated the circadian role of additional “positive” genes, selected for the strong behavioral defect induced by the expression of the corresponding RNAi. The CG12082 gene codes for the fruit fly ortholog of the human Ubiquitin-specific protease 5 (USP5). Downregulation of USP5 in clock cells lengthens the period of locomotor activity of flies as well as PER protein oscillations in clock neurons. High molecular weight forms of PER and TIM proteins accumulate during the morning after USP5 knockdown, while these forms are degraded in controls. In addition, TIM is not stabilized in the absence of PER, while PER still accumulate in the absence of TIM. Therefore, USP5 directly participates in the degradation of the PER protein and, later, of the TIM protein at the end of the cycle. Being a deubiquitinylase enzyme, USP5 may directly deubiquitinate PER. However, accordingly to the role described for the human ortholog, USP5 likely controls protein degradation through the disassembling of the unanchored polyubiquitin chains present in the cell that could compete with ubiquitinated-PER for proteasome recognition and subsequent breakdown.The majority of the work has focused on an unknown gene isolated in the screen, that, accordingly to the human homolog, we named STRIP. We show that STRIP interacts with Connector of Kinase to AP-1 (CKA), a novel regulatory subunit for the PP2A phosphatase holoenzyme, both in insect S2 cells and in fly head extracts. Downregulation of both STRIP and/or CKA causes long-period behavioral phenotypes and high molecular weight forms of the CLK protein to accumulate in the morning. Perturbation of general PP2A activities also produces hyper-phosphorylated CLK in the morning indicating that, through CKA/STRIP, PP2A complexes controls CLK dephosphorylation at the end of the cycle. Hyper-phosphorylated CLK forms are transcriptionally inactive. Accordingly, transcription of the tim and vrille (vri) CLK targets is strongly reduced in Cka-RNAi fly head extracts. PP2A complexes containing the Widerborst (WDB) regulatory subunits were already shown to affect CLK stability in insect S2 cells (Kim and Edery, 2006). We show that WDB downregulation also affects the stability of CLK in fly head extracts, but has no apparent effects on CLK phosphorylation. Therefore, we could describe two different PP2A complexes acting on the CLK protein: PP2A/CKA/STRIP complex controls CLK dephosphorylation and reactivation, while PP2A/WDB affects CLK stability independently or after PP2A/CKA functions. Moreover, STRIP, but not CKA, downregulation affects the stability of PER, indicating that STRIP possesses some functions unrelated to CKA. In conclusion, this work has allowed the isolation of new components of the Drosophila molecular clock. In particular, we give evidence for a double role for the PP2A phosphatase in modulating the activity and stability of the CLK protein, the regulation of which is not well understood yet." @default.
- W36155295 created "2016-06-24" @default.
- W36155295 creator A5065812865 @default.
- W36155295 date "2013-12-13" @default.
- W36155295 modified "2023-09-26" @default.
- W36155295 title "Analysis of new genes controlling Drosophila melanogaster rest-activity rhythms" @default.
- W36155295 hasPublicationYear "2013" @default.
- W36155295 type Work @default.
- W36155295 sameAs 36155295 @default.
- W36155295 citedByCount "0" @default.
- W36155295 crossrefType "dissertation" @default.
- W36155295 hasAuthorship W36155295A5065812865 @default.
- W36155295 hasConcept C104317684 @default.
- W36155295 hasConcept C121446783 @default.
- W36155295 hasConcept C144543706 @default.
- W36155295 hasConcept C150194340 @default.
- W36155295 hasConcept C158448853 @default.
- W36155295 hasConcept C166703698 @default.
- W36155295 hasConcept C169760540 @default.
- W36155295 hasConcept C173396325 @default.
- W36155295 hasConcept C184738001 @default.
- W36155295 hasConcept C2778880379 @default.
- W36155295 hasConcept C2780104201 @default.
- W36155295 hasConcept C38606739 @default.
- W36155295 hasConcept C54355233 @default.
- W36155295 hasConcept C67705224 @default.
- W36155295 hasConcept C86803240 @default.
- W36155295 hasConcept C95444343 @default.
- W36155295 hasConceptScore W36155295C104317684 @default.
- W36155295 hasConceptScore W36155295C121446783 @default.
- W36155295 hasConceptScore W36155295C144543706 @default.
- W36155295 hasConceptScore W36155295C150194340 @default.
- W36155295 hasConceptScore W36155295C158448853 @default.
- W36155295 hasConceptScore W36155295C166703698 @default.
- W36155295 hasConceptScore W36155295C169760540 @default.
- W36155295 hasConceptScore W36155295C173396325 @default.
- W36155295 hasConceptScore W36155295C184738001 @default.
- W36155295 hasConceptScore W36155295C2778880379 @default.
- W36155295 hasConceptScore W36155295C2780104201 @default.
- W36155295 hasConceptScore W36155295C38606739 @default.
- W36155295 hasConceptScore W36155295C54355233 @default.
- W36155295 hasConceptScore W36155295C67705224 @default.
- W36155295 hasConceptScore W36155295C86803240 @default.
- W36155295 hasConceptScore W36155295C95444343 @default.
- W36155295 hasLocation W361552951 @default.
- W36155295 hasOpenAccess W36155295 @default.
- W36155295 hasPrimaryLocation W361552951 @default.
- W36155295 hasRelatedWork W1540772015 @default.
- W36155295 hasRelatedWork W1982268494 @default.
- W36155295 hasRelatedWork W2023651881 @default.
- W36155295 hasRelatedWork W2044288080 @default.
- W36155295 hasRelatedWork W2052426890 @default.
- W36155295 hasRelatedWork W2052531367 @default.
- W36155295 hasRelatedWork W2056046790 @default.
- W36155295 hasRelatedWork W2066718019 @default.
- W36155295 hasRelatedWork W2094214035 @default.
- W36155295 hasRelatedWork W2133605119 @default.
- W36155295 hasRelatedWork W2142292113 @default.
- W36155295 hasRelatedWork W2154076545 @default.
- W36155295 hasRelatedWork W2157066823 @default.
- W36155295 hasRelatedWork W2158680198 @default.
- W36155295 hasRelatedWork W2169368064 @default.
- W36155295 hasRelatedWork W2169950401 @default.
- W36155295 hasRelatedWork W2327389097 @default.
- W36155295 hasRelatedWork W2539791934 @default.
- W36155295 hasRelatedWork W2916780225 @default.
- W36155295 hasRelatedWork W3192993898 @default.
- W36155295 isParatext "false" @default.
- W36155295 isRetracted "false" @default.
- W36155295 magId "36155295" @default.
- W36155295 workType "dissertation" @default.