Pathway
Activation of the phototransduction cascade
The photoreceptor cascade starts with light isomerization of 11-cis-retinal (11cRAL) of rhodopsin (RHO) to all-trans-retinal (atRAL), inducing a conformational change in RHO to the active, metarhodopsin II (MII) state. MII activates the G protein transducin (Gt) that in turn activates phosphodiesterase 6 (PDE6). Consequently, there is a fall in the intracellular concentration of cGMP that closes cGMP-dependent cation channels (CNG channels) and hyperpolarizes the rod. This has the effect of reducing or stopping glutamate release from synaptic vesicles thus signalling to the surrounding cells how many photons were absorbed.
What the reference databases state
Statements
11 statements
11 statements · 1 reference database · Subject: Activation of the phototransduction cascade · Sources: Reactome
- CNGA1 participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- CNGB1 participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- GNAT1 participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- GNB1 participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- GNGT1 participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- PDE6A participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- PDE6B participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- PDE6G participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- RHO participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- SAG participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only
- SLC24A1 participates in Activation of the phototransduction cascadeProteinReactome R-HSA-2485179Inferred only