Mechanosensitivity is an essential component of phototransduction in vertebrate rods

Ulisse Bocchero; Fabio Falleroni; Simone Mortal; Yunzhen Li; Dan Cojoc; Trevor Lamb; Vincent Torre

doi:10.1371/journal.pbio.3000750

Mechanosensitivity is an essential component of phototransduction in vertebrate rods

PLoS Biol. 2020 Jul 15;18(7):e3000750. doi: 10.1371/journal.pbio.3000750. eCollection 2020 Jul.

Authors

Ulisse Bocchero¹, Fabio Falleroni¹, Simone Mortal¹, Yunzhen Li¹, Dan Cojoc², Trevor Lamb³, Vincent Torre^{1

4

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Affiliations

¹ Neurobiology Department, International School for Advanced Studies, Trieste, Italy.
² Institute of Materials, National Research Council of Italy (CNR), Trieste, Italy.
³ Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australia.
⁴ Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Zhejiang, China.
⁵ Center of Systems Medicine, Chinese Academy of Medical Sciences, Suzhou Institute of Systems Medicine, Suzhou Industrial Park, Suzhou, China.

Abstract

Photoreceptors are specialized cells devoted to the transduction of the incoming visual signals. Rods are able also to shed from their tip old disks and to synthesize at the base of the outer segment (OS) new disks. By combining electrophysiology, optical tweezers (OTs), and biochemistry, we investigate mechanosensitivity in the rods of Xenopus laevis, and we show that 1) mechanosensitive channels (MSCs), transient receptor potential canonical 1 (TRPC1), and Piezo1 are present in rod inner segments (ISs); 2) mechanical stimulation-of the order of 10 pN-applied briefly to either the OS or IS evokes calcium transients; 3) inhibition of MSCs decreases the duration of photoresponses to bright flashes; 4) bright flashes of light induce a rapid shortening of the OS; and 5) the genes encoding the TRPC family have an ancient association with the genes encoding families of protein involved in phototransduction. These results suggest that MSCs play an integral role in rods' phototransduction.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Calcium / metabolism
Fluorescence
Light
Light Signal Transduction* / radiation effects
Mechanotransduction, Cellular* / radiation effects
Multigene Family
Photic Stimulation
Retinal Rod Photoreceptor Cells / metabolism*
Retinal Rod Photoreceptor Cells / radiation effects
TRPC Cation Channels / genetics
Xenopus Proteins / genetics
Xenopus laevis / metabolism*

Substances

TRPC Cation Channels
TRPC1 protein, Xenopus
Xenopus Proteins
Calcium

Grants and funding

The entire study was funded by the International School for Advanced Studies. VT received the funding. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.