title: Proteomic analysis of day-night variations in protein levels in the rat pineal gland.
abstract: The pineal gland secretes the hormone melatonin. This secretion exhibits a circadian rhythm with a zenith during night and a nadir during day. We have performed proteome analysis of the superficial pineal gland in rats during daytime and nighttime. The proteins were extracted and subjected to 2-DE. Of 1747 protein spots revealed by electrophoresis, densitometric analysis showed the up-regulation of 25 proteins during nighttime and of 35 proteins during daytime. Thirty-seven of the proteins were identified by MALDI-TOF MS. The proteins up-regulated during the night are involved in the Krebs cycle, energy transduction, calcium binding, and intracellular transport. During the daytime, enzymes involved in glycolysis, electron transport, and also the Krebs cycle were up-regulated as well as proteins taking part in RNA binding and RNA processing. Our data show a prominent day-night variation of the protein levels in the rat pineal gland. Some proteins are up-regulated during the night concomitant with the melatonin secretion of the gland. Other proteins are up-regulated during the day indicating a pineal metabolism not related to the melatonin synthesis.
authors.affiliation: Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark. morten.m@mai.ku.dk
authors.forename: Morten
authors.initials: M
authors.lastname: Møller
authors.forename: Thomas
authors.initials: T
authors.lastname: Sparre
authors.forename: Nicolai
authors.initials: N
authors.lastname: Bache
authors.forename: Peter
authors.initials: P
authors.lastname: Roepstorff
authors.forename: Henrik
authors.initials: H
authors.lastname: Vorum
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D008297:Male; D010870:Pineal Gland / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D020543:Proteome