A differential response of two putative mammalian circadian regulators, mper1 and mper2, to light.
A mouse gene, mper1, having all the properties expected of a circadian clock gene, was reported recently. This gene is expressed in a circadian pattern in the suprachiasmatic nucleus (SCN). mper1 maintains this pattern of circadian expression in constant darkness and can be entrained to a new light/dark cycle. Here we report the isolation of a second mammalian gene, mper2, which also has these properties and greater homology to Drosophila period. Expression of mper1 and mper2 is overlapping but asynchronous by 4 hr. mper1, unlike period and mper2, is expressed rapidly after exposure to light at CT22. It appears that mper1 is the pacemaker component which responds to light and thus mediates photic entrainment.
Albrecht
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Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030, USA.
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Eichele
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Lee
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D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000235:genetics / Q000528:radiation effects*; D018076:DNA, Complementary / Q000737:chemistry; D015870:Gene Expression / Q000528:radiation effects; D008027:Light; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000528:radiation effects*; D056950:Period Circadian Proteins; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D009687:Nuclear Proteins; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D014157:Transcription Factors