| First Author | Sato S | Year | 2020 |
| Journal | Proc Natl Acad Sci U S A | Volume | 117 |
| Issue | 43 | Pages | 26996-27003 |
| PubMed ID | 33046651 | Mgi Jnum | J:303333 |
| Mgi Id | MGI:6471269 | Doi | 10.1073/pnas.2009164117 |
| Citation | Sato S, et al. (2020) Rhodopsin-mediated light-off-induced protein kinase A activation in mouse rod photoreceptor cells. Proc Natl Acad Sci U S A 117(43):26996-27003 |
| abstractText | Light-induced extrasynaptic dopamine release in the retina reduces adenosine 3',5'-cyclic monophosphate (cAMP) in rod photoreceptor cells, which is thought to mediate light-dependent desensitization. However, the fine time course of the cAMP dynamics in rods remains elusive due to technical difficulty. Here, we visualized the spatiotemporal regulation of cAMP-dependent protein kinase (PKA) in mouse rods by two-photon live imaging of retinal explants of PKAchu mice, which express a fluorescent biosensor for PKA. Unexpectedly, in addition to the light-on-induced suppression, we observed prominent light-off-induced PKA activation. This activation required photopic light intensity and was confined to the illuminated rods. The estimated maximum spectral sensitivity of 489 nm and loss of the light-off-induced PKA activation in rod-transducin-knockout retinas strongly suggest the involvement of rhodopsin. In support of this notion, rhodopsin-deficient retinal explants showed only the light-on-induced PKA suppression. Taken together, these results suggest that, upon photopic light stimulation, rhodopsin and dopamine signals are integrated to shape the light-off-induced cAMP production and following PKA activation. This may support the dark adaptation of rods. |
