ABCR Pathway
Under some circumstances, the spent chromophore may leave the opsin molecule prior to its replacement, when it is bound to the ABCR protein, when it is also transformed to all-trans retinol, and then leaves the photoreceptor outer segment via the IRBP chaperone. It then follows the conventional pathway of recycling. It is from this pathway that the presence of opsin without a chromophore can be explained.
Read more about this topic: Bleach And Recycle
Famous quotes containing the word pathway:
“And open field, through which the pathway wound,
And homeward led my steps. Magnificent
The morning rose, in memorable pomp,
Glorious as e’er I had beheld—in front,
The sea lay laughing at a distance; near,
The solid mountains shone, bright as the clouds,
Grain-tinctured, drenched in empyrean light;”
—William Wordsworth (1770–1850)