Circadian expression of hnRNP U, a nuclear multi-potent regulatory protein, in the murine suprachiasmatic nucleus.
Heterogeneous ribonuclear protein U (hnRNP U/SAF-A) is a nuclear multi-potent regulatory protein. We investigated whether hnRNP U protein and transcript levels undergo circadian changes by immunoblot and quantitative RT-PCR analyses. In the suprachiasmatic nucleus (SCN), hnRNP U immunoreactivity (ir) changed in a robust circadian pattern as it showed a peak at late nighttime in both light/dark and constant dark conditions. hnRNP U transcript levels in the SCN changed in a similar circadian pattern. In the hippocampus, hnRNP transcript levels also showed a peak at late nighttime but hnRNP U-ir showed an opposite pattern as it peaked at late daytime. These findings suggest that hnRNP U participates in nuclear regulatory events that are involved in mammalian central and peripheral circadian clocks.
Tamaru
Teruya
T
Department of Physiology, Toho University School of Medicine, 5-21-16 Ohmori-nishi, Ohta-ku, 143-8540, Tokyo, Japan. tetamaru@med.toho-u.ac.jp
Isojima
Yasushi
Y
Nagai
Katsuya
K
Takamatsu
Ken
K
D000818:Animals; D015153:Blotting, Western; D002940:Circadian Rhythm / Q000502:physiology*; D005786:Gene Expression Regulation; D034722:Heterogeneous-Nuclear Ribonucleoprotein U / Q000235:genetics / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*
D034722:Heterogeneous-Nuclear Ribonucleoprotein U; D012333:RNA, Messenger