Circadian proteomics of the mouse retina.
The circadian clock in the retina regulates a variety of physiological phenomena such as disc shedding and melatonin release. Although these events are critical for retinal functions, it is almost unknown how the circadian clock controls the physiological rhythmicity. To gain insight into the processes, we performed a proteomic analysis using 2-DE to find proteins whose levels show circadian changes. Among 415 retinal protein spots, 11 protein spots showed circadian rhythmicity in their intensities. We performed MALDI-TOF MS and NanoLC-MS/MS analyses and identified proteins contained in the 11 spots. The proteins were related to vesicular transport, calcium-binding, protein degradation, metabolism, RNA-binding, and protein foldings, suggesting the clock-regulation of neurotransmitter release, transportation of the membrane proteins, calcium-binding capability, and so on. We also found a rhythmic phosphorylation of N-ethylmaleimide-sensitive fusion protein and identified one of the amino acid residues modified by phosphorylation. These findings provide a new perspective on the relationship between the physiological functions of the retina and the circadian clock system.
Tsuji
Takahiro
T
Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
Hirota
Tsuyoshi
T
Takemori
Nobuaki
N
Komori
Naoka
N
Yoshitane
Hikari
H
Fukuda
Masafumi
M
Matsumoto
Hiroyuki
H
Fukada
Yoshitaka
Y
D000818:Animals; D001683:Biological Clocks / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D005136:Eye Proteins / Q000032:analysis*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012160:Retina / Q000737:chemistry / Q000502:physiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D005136:Eye Proteins