Project/Area Number |
07309020
|
Research Category |
Grant-in-Aid for Scientific Research (A)
|
Allocation Type | Single-year Grants |
Section | 総合 |
Research Field |
広領域
|
Research Institution | The University of Tokyo |
Principal Investigator |
FUKUDA Yoshitaka Univ. Tokyo, Grad. Sch. Sci., Prof., 大学院・理学系研究科, 教授 (80165258)
|
Co-Investigator(Kenkyū-buntansha) |
TOMIOKA Kenji Yamaguchi Univ., Fac. Sci., Prof., 理学部, 教授 (30136163)
KAWAMURA Satoru Osaka Univ., Grad. Sch. Sci., Prof., 大学院・理学研究科, 教授 (80138122)
TSUDA Motoyuki Himeji Inst. Tech., Prof., 理学部, 教授 (60045458)
TOKUNAGA Fumio Osaka Univ., Grad. Sch. Sci., Prof., 大学院・理学研究科, 教授 (80025452)
TSUKAHARA Yasuo Tohoku Univ., Grad. Sch.Info. Sci., Prof., 大学院・情報科学研究科, 教授 (60004587)
|
Project Period (FY) |
1995 – 1996
|
Project Status |
Completed (Fiscal Year 1996)
|
Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1996: ¥6,200,000 (Direct Cost: ¥6,200,000)
|
Keywords | Pineal Organ / Rod / Cone / Photoreceptor / G-protein / Calcium ion / Circadian Rhythm / Photon-Signal Transduction |
Research Abstract |
Animals respond to light in a wide rage of time scale. A photon signalis transduced in the retinal photoreceptor in a sub-second time scale for vision, while the light signal is utilized for resetting the phase of circadian clock which controls the daily change of animal physiology. This project aimed at comparative studies on the photon-signal transduction processes in the two types of photoresponses for the vision and the biological clock. <Retinal phototransduction pathways> To see the molecular mechanism that underlies the physiological difference in photoresponse between rod and cone photoreceptors, rhodopsin and cone pigment mutants were expressed in the cultured cells and affinity-purified. Spectrophotometric studies pinpointed a single amino acid residue that determines whether the photoreceptive molecule is rod-or cone-type. S-modulin and a novel S-modulin-like calcium-binding protein, termed s26 protein, were biochemically characterized to reveal how the calcium ion modulates
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a photosensitivity of vertebrate rod and cone photoreceptors. A rhodopsin kinase of invertebrate photoreceptors was also characterized to show that it is similar to vertebrate rhodopsin kinase and also to beta-adrenergic receptor kinase in non-retinal tissues. <Biological clock and pineal photoreception> The neural pathways involved in mutual interactions between the paired pacemakers in the optic lobes of the cricket were determined by electric recording of the neural activity. In fishes, temperature-signal as well as light-signal was shown to be able to drive the melatonin rhythm. The photoreceptor cells in the lamprey pineal gland were classified into several groups by using specific antibodies to serotonin and retinal opsins. Immunocytochemistry of the chicken pineal gland also revealed the presence of a novel type of photoreceptive cells with long ciliary structure in the periphery of the follicles in addition to the follicular pinealocytes having photoreceptive molecule (s) in the regressed outer segments. In the course of these studies, the 15 team investigators in the research areas of vision and chronobiology have made a fruitful collaboration, and understand the important interactions between these areas in Japan. Less
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