title: Dec1 and Dec2 expression is disrupted in the suprachiasmatic nuclei of Clock mutant mice.
abstract: DEC1 and DEC2 are basic helix-loop-helix transcription factors that functionally resemble negative feedback components of the mammalian circadian clock. The genes Dec1 and Dec2 are expressed rhythmically in the rat suprachiasmatic nuclei, and Dec1 expression is stimulated by light in a time-dependent manner with the kinetics of an immediate early gene. DEC1 and DEC2 can inhibit CLOCK:BMAL1 transactivation of the clock gene Per1, suggesting that these transcription factors may help regulate circadian timing. The authors present data on the expression pattern of Dec1 and Dec2 in wild-type and homozygous Clock mutant mice. In the suprachiasmatic nuclei, the Clock mutation significantly reduces the expression of Dec1 and Dec2. Dec1 becomes arrhythmic; Dec2 remains weakly rhythmic in a 12L:12D light-dark cycle but is arrhythmic in constant darkness. A robust attenuation of the Dec1 and Dec2 signals in Clock mutant mice was detected in all brain areas examined. These data point to up-regulation of Dec1 and Dec2 by Clock in vivo.
authors.affiliation: Department of Physiology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
authors.forename: Matthew Preston
authors.initials: MP
authors.lastname: Butler
authors.forename: Sato
authors.initials: S
authors.lastname: Honma
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fukumoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawamoto
authors.forename: Katsumi
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Mitsuhide
authors.initials: M
authors.lastname: Noshiro
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kato
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Honma
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D001921:Brain / Q000378:metabolism; D056926:CLOCK Proteins; D005786:Gene Expression Regulation; D005838:Genotype; D018398:Homeodomain Proteins / Q000096:biosynthesis*; D017403:In Situ Hybridization; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D009154:Mutation; D012333:RNA, Messenger / Q000378:metabolism; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*; D013997:Time Factors; D015534:Trans-Activators / Q000096:biosynthesis* / Q000235:genetics*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; C470968:Bhlhb3 protein, mouse; C491539:Bhlhe40 protein, mouse; C491538:Bhlhe40 protein, rat; C538944:Clock protein, mouse; C538945:Clock protein, rat