title: Expression and role of TTF-1 in the rat suprachiasmatic nucleus.
abstract: We have previously reported that TTF-1, a homeodomain-containing transcription factor, regulates circadian rhythm of pituitary adenylate cyclase-activating polypeptide gene expression in the rat hypothalamus. In this study we found that TTF-1 mRNA was specifically expressed in the rat suprachiasmatic nucleus (SCN) and colocalized with Period 2 (Per2), a circadian feedback loop controller. Interaction between TTF-1 and Per1 and Per2 was demonstrated by immunoprecipitation and immunoblot assays. Moreover, TTF-1 and Per proteins additively stimulated a transcriptional activity of angiotensinogen (AoGen) gene. TTF-1 also activated in vitro rhythm of AoGen transcription determined by secretary alkaline phosphatase (SEAP) reporter system in the NIH3T3 cells. These results suggest that TTF-1 plays a role in the circadian rhythm regulation of the AoGen gene expression via interacting with Per proteins in the rat SCN.
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, University of Ulsan, San29, Mugeodong, Namgu, Ulsan 680-749, South Korea.
authors.forename: Young June
authors.initials: YJ
authors.lastname: Son
authors.forename: Chang Ho
authors.initials: CH
authors.lastname: Yun
authors.forename: Jae Geun
authors.initials: JG
authors.lastname: Kim
authors.forename: Jeong Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Sung Goo
authors.initials: SG
authors.lastname: Kang
authors.forename: Byung Ju
authors.initials: BJ
authors.lastname: Lee
mesh_terms: D000808:Angiotensinogen / Q000235:genetics*; D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics*; D005786:Gene Expression Regulation; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D056950:Period Circadian Proteins; D051381:Rats; D017207:Rats, Sprague-Dawley; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; C000614416:Nkx2-1 protein, rat; D009687:Nuclear Proteins; C539024:Per1 protein, rat; C513311:Per2 protein, rat; D056950:Period Circadian Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D000808:Angiotensinogen