The Disease Protein Tulp1 Is Essential for Periactive Zone Endocytosis in Photoreceptor Ribbon Synapses.

TitleThe Disease Protein Tulp1 Is Essential for Periactive Zone Endocytosis in Photoreceptor Ribbon Synapses.
Publication TypeJournal Article
Year of Publication2016
AuthorsWahl S, Magupalli VGiri, Dembla M, Katiyar R, Schwarz K, Köblitz L, Alpadi K, Krause E, Rettig J, Sung C-H, Goldberg AFX, Schmitz F
JournalJ Neurosci
Volume36
Issue8
Pagination2473-93
Date Published2016 Feb 24
ISSN1529-2401
KeywordsAmino Acid Sequence, Animals, Cattle, Endocytosis, Eye Proteins, Female, HEK293 Cells, Humans, Male, Mice, Mice, Knockout, Molecular Sequence Data, Organ Culture Techniques, Photoreceptor Cells, Retina, Synapses
Abstract

Mutations in the Tulp1 gene cause severe, early-onset retinitis pigmentosa (RP14) in humans. In the retina, Tulp1 is mainly expressed in photoreceptors that use ribbon synapses to communicate with the inner retina. In the present study, we demonstrate that Tulp1 is highly enriched in the periactive zone of photoreceptor presynaptic terminals where Tulp1 colocalizes with major endocytic proteins close to the synaptic ribbon. Analyses of Tulp1 knock-out mice demonstrate that Tulp1 is essential to keep endocytic proteins enriched at the periactive zone and to maintain high levels of endocytic activity close to the synaptic ribbon. Moreover, we have discovered a novel interaction between Tulp1 and the synaptic ribbon protein RIBEYE, which is important to maintain synaptic ribbon integrity. The current findings suggest a new model for Tulp1-mediated localization of the endocytic machinery at the periactive zone of ribbon synapses and offer a new rationale and mechanism for vision loss associated with genetic defects in Tulp1.

DOI10.1523/JNEUROSCI.2275-15.2016
Alternate JournalJ. Neurosci.
PubMed ID26911694
PubMed Central IDPMC4764665
Grant ListEY11307 / EY / NEI NIH HHS / United States
EY016805 / EY / NEI NIH HHS / United States
R01 EY016805 / EY / NEI NIH HHS / United States
R01 EY013246 / EY / NEI NIH HHS / United States
EY013246 / EY / NEI NIH HHS / United States
R01 EY011307 / EY / NEI NIH HHS / United States