Presynaptic localization of GluK5 in rod photoreceptors suggests a novel function of high affinity glutamate receptors in the mammalian retina

Iris Haumann; Dirk Junghans; Max Anstötz; Michael Frotscher

doi:10.1371/journal.pone.0172967

Presynaptic localization of GluK5 in rod photoreceptors suggests a novel function of high affinity glutamate receptors in the mammalian retina

PLoS One. 2017 Feb 24;12(2):e0172967. doi: 10.1371/journal.pone.0172967. eCollection 2017.

Authors

Iris Haumann¹, Dirk Junghans², Max Anstötz¹, Michael Frotscher³

Affiliations

¹ Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
² Institute of Embryology and Stem Cell Biology, Department of Biomedicine, University of Basel, Basel, Switzerland.
³ Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

Abstract

Kainate receptors mediate glutamatergic signaling through both pre- and presynaptic receptors. Here, we studied the expression of the high affinity kainate receptor GluK5 in the mouse retina. Double-immunofluoresence labeling and electron microscopic analysis revealed a presynaptic localization of GluK5 in the outer plexiform layer. Unexpectedly, we found GluK5 almost exclusively localized to the presynaptic ribbon of photoreceptor terminals. Moreover, in GluK5-deficient mutant mice the structural integrity of synaptic ribbons was severely altered pointing to a novel function of GluK5 in organizing synaptic ribbons in the presynaptic terminals of rod photoreceptors.

MeSH terms

Alcohol Oxidoreductases
Animals
Co-Repressor Proteins
DNA-Binding Proteins / metabolism
Mice, 129 Strain
Mice, Inbred C57BL
Mice, Knockout
Organ Specificity
Phosphoproteins / metabolism
Presynaptic Terminals / metabolism*
Protein Transport
Receptors, Kainic Acid / metabolism*
Retina / metabolism
Retina / ultrastructure
Retinal Rod Photoreceptor Cells / metabolism*
Retinal Rod Photoreceptor Cells / ultrastructure

Substances

Co-Repressor Proteins
DNA-Binding Proteins
Gluk1 kainate receptor
Phosphoproteins
Receptors, Kainic Acid
Alcohol Oxidoreductases
Ctbp2 protein, mouse

Grants and funding

This work was supported by the German Research Foundation (FR 620/14-1 to MF); Landesforschungsförderung by the State of Hamburg (LFF-FV27, project P3) to MF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.