Article abstract


Nature Neuroscience 11, 923 - 931 (2008)
Published online: 20 July 2008 | doi:10.1038/nn.2160

Pikachurin, a dystroglycan ligand, is essential for photoreceptor ribbon synapse formation

Shigeru Sato1,2,3, Yoshihiro Omori1, Kimiko Katoh1, Mineo Kondo4, Motoi Kanagawa5, Kentaro Miyata4, Kazuo Funabiki6, Toshiyuki Koyasu4, Naoko Kajimura7, Tomomitsu Miyoshi8, Hajime Sawai8, Kazuhiro Kobayashi5, Akiko Tani1, Tatsushi Toda5, Jiro Usukura9, Yasuo Tano2, Takashi Fujikado2,3 & Takahisa Furukawa1


Exquisitely precise synapse formation is crucial for the mammalian CNS to function correctly. Retinal photoreceptors transfer information to bipolar and horizontal cells at a specialized synapse, the ribbon synapse. We identified pikachurin, an extracellular matrix–like retinal protein, and observed that it localized to the synaptic cleft in the photoreceptor ribbon synapse. Pikachurin null-mutant mice showed improper apposition of the bipolar cell dendritic tips to the photoreceptor ribbon synapses, resulting in alterations in synaptic signal transmission and visual function. Pikachurin colocalized with both dystrophin and dystroglycan at the ribbon synapses. Furthermore, we observed direct biochemical interactions between pikachurin and dystroglycan. Together, our results identify pikachurin as a dystroglycan-interacting protein and demonstrate that it has an essential role in the precise interactions between the photoreceptor ribbon synapse and the bipolar dendrites. This may also advance our understanding of the molecular mechanisms underlying the retinal electrophysiological abnormalities observed in muscular dystrophy patients.

Top
  1. Department of Developmental Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka, 565-0874, Japan.
  2. Department of Ophthalmology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
  3. Department of Visual Science, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
  4. Department of Ophthalmology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, 466-8550, Japan.
  5. Division of Clinical Genetics, Department of Medical Genetics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
  6. Department of Systems Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka, 565-0874, Japan.
  7. Research Center for Ultrahigh-Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
  8. Department of Physiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
  9. Department of Materials Physics and Engineering, Nagoya University Graduate School of Engineering, 1-1 Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan.

Correspondence to: Takashi Fujikado2,3 e-mail: furukawa@obi.or.jp



MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.

REVIEWS

Parallel processing in the mammalian retina

Nature Reviews Neuroscience Review (01 Oct 2004)

See all 13 matches for Reviews

NEWS AND VIEWS

Unraveling the ribbon synapse

Nature Neuroscience News and Views (01 Aug 2008)

Long-distance signaling via presynaptic glutamate transporters

Nature Neuroscience News and Views (01 Nov 2006)