Expression and role of TTF-1 in the rat suprachiasmatic nucleus.
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.
Son
Young June
YJ
Department of Biological Sciences, College of Natural Sciences, University of Ulsan, San29, Mugeodong, Namgu, Ulsan 680-749, South Korea.
Yun
Chang Ho
CH
Kim
Jae Geun
JG
Park
Jeong Woo
JW
Kim
Jong Hyun
JH
Kang
Sung Goo
SG
Lee
Byung Ju
BJ
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*
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