Molecular clock regulates daily α1-2-fucosylation of the neural cell adhesion molecule (NCAM) within mouse secondary olfactory neurons.
The circadian clock regulates various behavioral and physiological rhythms in mammals. Circadian changes in olfactory functions such as neuronal firing in the olfactory bulb (OB) and olfactory sensitivity have recently been identified, although the underlying molecular mechanisms remain unknown. We analyzed the temporal profiles of glycan structures in the mouse OB using a high-density microarray that includes 96 lectins, because glycoconjugates play important roles in the nervous system such as neurite outgrowth and synaptogenesis. Sixteen lectin signals significantly fluctuated in the OB, and the intensity of all three that had high affinity for α1-2-fucose (α1-2Fuc) glycan in the microarray was higher during the nighttime. Histochemical analysis revealed that α1-2Fuc glycan is located in a diurnal manner in the lateral olfactory tract that comprises axon bundles of secondary olfactory neurons. The amount of α1-2Fuc glycan associated with the major target glycoprotein neural cell adhesion molecule (NCAM) varied in a diurnal fashion, although the mRNA and protein expression of Ncam1 did not. The mRNA and protein expression of Fut1, a α1-2-specific fucosyltransferase gene, was diurnal in the OB. Daily fluctuation of the α1-2Fuc glycan was obviously damped in homozygous Clock mutant mice with disrupted diurnal Fut1 expression, suggesting that the molecular clock governs rhythmic α1-2-fucosylation in secondary olfactory neurons. These findings suggest the possibility that the molecular clock is involved in the diurnal regulation of olfaction via α1-2-fucosylation in the olfactory system.
From the Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, the Department of Basic Veterinary Medicine, Laboratory of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555.
Daisuke
D
Kondoh
the Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568.
Hiroaki
H
Tateno
the Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568.
Jun
J
Hirabayashi
From the Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, the Department of Applied Biological Science, Graduate School of Science and Technology, Tokyo University of Science, Noda 278-8510, and.
Yuki
Y
Yasumoto
From the Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566.
Reiko
R
Nakao
From the Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, the Department of Applied Biological Science, Graduate School of Science and Technology, Tokyo University of Science, Noda 278-8510, and the Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan k-ooishi@aist.go.jp.
Katsutaka
K
Oishi
D000818:Animals; D019002:CD56 Antigen / Q000378:metabolism*; D056926:CLOCK Proteins / Q000235:genetics*; D002940:Circadian Rhythm; D005643:Fucose / Q000378:metabolism; D005647:Fucosyltransferases / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation; D006031:Glycosylation; D008297:Male; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D009832:Olfactory Nerve / Q000166:cytology; D018034:Olfactory Receptor Neurons / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D000097631:Galactoside 2-alpha-L-fucosyltransferase
D019002:CD56 Antigen; D056926:CLOCK Proteins; D005643:Fucose; D005647:Fucosyltransferases; D000097631:Galactoside 2-alpha-L-fucosyltransferase; C501063:Ncam1 protein, mouse; C538944:Clock protein, mouse
Circadian Rhythm; Clock Gene; Glycosylation; Lectin; Olfaction