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Updated: Jan 8, 2026

Two Peeling Methods for the Isolation of Photoreceptor Cell Compartments in the Mouse Retina for Protein Analysis
Published on: December 7, 2021
A Mouse Photoreceptor Proteome Resource Identifies PALS2/MPP6 as a Novel Pan-Cone Photoreceptor Marker
Uwe Thorsten Lux1, Kerstin Reim2, Johannes Leonhard Krupp1
1Department of Biology, Division of Animal Physiology/Neurobiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
Purpose:
To generate a quantitative proteome expression resource of rod and cone photoreceptors from the mouse retina that allows the exploration of cell type-specific proteomic landscapes.
Methods:
Fluorescence-activated cell sorting of rod and cone photoreceptors was followed by in-solution digestion with trypsin using filter-aided sample preparation. Mass spectrometry analysis was performed using data-independent acquisition (DIA).
Results:
Demonstrating the potential of our proteome resource, we identified PALS2 (protein associated with LIN7 2), also known as MPP6 (membrane palmitoylated protein 6), as a protein present in cone photoreceptors but absent in rod photoreceptors. We established PALS2/MPP6 as a novel pan-cone photoreceptor marker. Importantly, the high protein sequence coverage of DIA mass spectrometry allows one to gain deeper insights into photoreceptor type-specific protein isoforms. We show this with examples of PALS2/MPP6 and different synaptic proteins.
Conclusions:
Our quantitative proteome resource provides comprehensive details on the protein composition of mouse rod and cone photoreceptors and identifies PALS2/MPP6 as a novel pan-cone photoreceptor marker.

