Frmpd1 Facilitates Trafficking of G-Protein Transducin and Modulates Synaptic Function in Rod Photoreceptors of Mammalian Retina.

ABSTRACT: Trafficking of transducin (Gα_t) in rod photoreceptors is critical for adaptive and modulatory responses of the retina to varying light intensities. In addition to fine-tuning phototransduction gain in rod outer segments (OSs), light-induced translocation of Gα_t to the rod synapse enhances rod to rod bipolar synaptic transmission. Here, we show that the rod-specific loss of Frmpd1 (FERM and PDZ domain containing 1), in the retina of both female and male mice, results in delayed return of Gα_t from the synapse back to outer segments in the dark, compromising the capacity of rods to recover from light adaptation. Frmpd1 directly interacts with Gpsm2 (G-protein signaling modulator 2), and the two proteins are required for appropriate sensitization of rod-rod bipolar signaling under saturating light conditions. These studies provide insight into how the trafficking and function of Gα_t is modulated to optimize the photoresponse and synaptic transmission of rod photoreceptors in a light-dependent manner.

SUBMITTER: Campla CK 

PROVIDER: S-EPMC9581579 | biostudies-literature | 2022 Sep-Oct

REPOSITORIES: biostudies-literature