title: The E3 ubiquitin ligase CTRIP controls CLOCK levels and PERIOD oscillations in Drosophila.
abstract: In the Drosophila circadian clock, the CLOCK/CYCLE complex activates the period and timeless genes that negatively feedback on CLOCK/CYCLE activity. The 24-h pace of this cycle depends on the stability of the clock proteins. RING-domain E3 ubiquitin ligases have been shown to destabilize PERIOD or TIMELESS. Here we identify a clock function for the circadian trip (ctrip) gene, which encodes a HECT-domain E3 ubiquitin ligase. ctrip expression in the brain is mostly restricted to clock neurons and its downregulation leads to long-period activity rhythms in constant darkness. This altered behaviour is associated with high CLOCK levels and persistence of phosphorylated PERIOD during the subjective day. The control of CLOCK protein levels does not require PERIOD. Thus, CTRIP seems to regulate the pace of the oscillator by controlling the stability of both the activator and the repressor of the feedback loop.
authors.affiliation: Institut de Neurobiologie Alfred Fessard, CNRS UPR3294, F-91190 Gif-sur-Yvette, France.
authors.forename: Angélique
authors.initials: A
authors.lastname: Lamaze
authors.forename: Annie
authors.initials: A
authors.lastname: Lamouroux
authors.forename: Carine
authors.initials: C
authors.lastname: Vias
authors.forename: Hsiu-Cheng
authors.initials: HC
authors.lastname: Hung
authors.forename: Frank
authors.initials: F
authors.lastname: Weber
authors.forename: François
authors.initials: F
authors.lastname: Rouyer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001683:Biological Clocks / Q000235:genetics; D001921:Brain / Q000378:metabolism; D056926:CLOCK Proteins / Q000378:metabolism*; D015536:Down-Regulation; D004330:Drosophila / Q000201:enzymology* / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D023061:Gene Order; D008297:Male; D008969:Molecular Sequence Data; D009043:Motor Activity / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D056950:Period Circadian Proteins / Q000378:metabolism*; D055550:Protein Stability; D034622:RNA Interference; D044767:Ubiquitin-Protein Ligases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D056926:CLOCK Proteins; D044767:Ubiquitin-Protein Ligases