In particular, an insomniac-Gal4 reporter is expressed in regions of the Drosophila brain that are implicated in regulating sleep, including the mushroom bodies and the pars intercerebralis ( Pitman et al., 2006, Joiner et al., 2006 and Foltenyi et al., 2007), although driving insomniac expression in these areas individually does not rescue the sleep defect of insomniac mutants, with the exception of a weak rescue provided by the pars-intercerebralis-specific Mai301-Gal4 driver. Further manipulations of insomniac within the nervous system are necessary to understand the neuroanatomical basis by which it regulates sleep. Several lines of

evidence indicate that insomniac exerts its effects on sleep by a mechanism functionally distinct from the circadian clock. The circadian clock is intact in insomniac mutants, and insomniac expression is not regulated in a circadian fashion. Furthermore, the expression

of insomniac Carfilzomib price this website in clock neurons is unable to restore normal sleep patterns in insomniac mutant backgrounds. Consistent with these data, daily sleep profiles indicate that the circadian control of sleep is intact in insomniac mutants. As is the case for wild-type animals, the highest probability of sleep during the dark phase is observed soon after the onset of darkness, with a decreasing sleep drive as the dark phase proceeds. The profile of sleep probability during the light phase is similarly intact. The principal alteration of sleep in insomniac animals is a reduced likelihood of sleeping throughout the day and night, consistent with the inference that insomniac may contribute to homeostatic

mechanisms that regulate sleep need. Cullins are scaffold proteins that assemble multisubunit E3 ubiquitin ligase complexes that ubiquitinate and degrade a variety of protein substrates in diverse only biological contexts (Petroski and Deshaies, 2005). The C termini of cullins interact with RING-domain ubiquitin ligases, while the N termini interact with adaptor proteins that recruit substrates for ubiquitination. Cul3 complexes utilize proteins of the BTB superfamily as their adaptors (Pintard et al., 2003, Xu et al., 2003 and Geyer et al., 2003), including members of the nonchannel KCTD subfamily (Chen et al., 2009 and Canettieri et al., 2010). In addition to the KCTD proteins that are known to function as Cul3 adaptors, more than half of the non-channel KCTD proteins, including the three vertebrate orthologs of Insomniac, are candidate Cul3 adaptors, as they copurify specifically with Cul3, but not with other cullins (Bennett et al., 2010). For several of these candidate adaptors, including KCTD5 and TAG-303, the C. elegans ortholog of Insomniac, independent biochemical evidence confirms their ability to associate physically with Cul3 ( Xu et al., 2003, Bayón et al., 2008 and De Smaele et al., 2011).