lecithin:11-cis retinol acyltransferase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: an 11-cis retinol-[cellular-retinol-binding-protein] + a phosphatidylcholine = a cellular-retinol-binding protein + an 11-cis-retinyl ester + a 1-lysophosphatidylcholine. [EC:2.3.1.135, GOC:pz]

Lecithin:11-cis retinol acyltransferase activity is a critical enzyme involved in the visual cycle, specifically in the regeneration of the visual pigment rhodopsin. This enzyme catalyzes the transfer of a fatty acid, typically palmitic acid, from a phospholipid molecule, phosphatidylcholine (lecithin), to the 11-cis retinol molecule. This process converts 11-cis retinol into 11-cis retinyl ester, which is a storage form of vitamin A.

The reaction occurs within the photoreceptor cells of the retina. Following light absorption by rhodopsin, the protein undergoes a series of conformational changes, ultimately leading to the release of 11-cis retinal from rhodopsin. This release triggers a cascade of signaling events that ultimately lead to visual perception.

The 11-cis retinal is then transported to the retinal pigment epithelium (RPE), where lecithin:11-cis retinol acyltransferase activity comes into play. The enzyme facilitates the esterification of 11-cis retinol to 11-cis retinyl ester. This esterified form is then transported back to the photoreceptor cells, where it can be reconverted to 11-cis retinal by another enzyme, retinol dehydrogenase.

In summary, lecithin:11-cis retinol acyltransferase activity plays a crucial role in the visual cycle by facilitating the regeneration of 11-cis retinal, ensuring continuous photoreceptor cell function and vision.'
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Proteins (1)

Compounds (2)