Tryptophan hydroxylase mRNA levels are regulated by the circadian clock, temperature, and cAMP in chick pineal cells. Brain Res 1996 Oct 28;738(1):1-7
Date
10/28/1996Pubmed ID
8949920DOI
10.1016/0006-8993(96)00743-3Scopus ID
2-s2.0-0030605164 (requires institutional sign-in at Scopus site) 26 CitationsAbstract
Chick pineal cells contain a circadian oscillator that derives rhythmic synthesis and secretion of melatonin even in dispersed cell culture. Here, we demonstrate that the mRNA encoding tryptophan hydroxylase (TPH), the first enzyme in the melatonin synthetic pathway, is expressed rhythmically under the control of the circadian clock. TPH message levels doubled between early day and early night, under both cyclic lightning and constant lightning conditions. The amplitude of the TPH mRNA rhythm was increased to 4-fold by culturing the cells at 43.3 degrees C for 48 h instead of 36.7 degrees C. Addition of forskolin to the cultures in early day produced a modest increase (50%) in TPH message levels but had no effect at other times. Because TPH mRNA are regulated by the endogenous pineal circadian clock, this provides a valuable system in which the molecular mechanism of clock control of gene expression.
Author List
Green CB, Besharse JC, Zatz MMESH terms used to index this publication - Major topics in bold
AnimalsAnimals, Newborn
Cells, Cultured
Chickens
Circadian Rhythm
Colforsin
Cyclic AMP
Light
Pineal Gland
RNA, Messenger
Temperature
Tryptophan Hydroxylase