retinol O-fatty-acyltransferase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: acyl-CoA + retinol = CoA + retinyl ester. [EC:2.3.1.76, MetaCyc:RETINOL-O-FATTY-ACYLTRANSFERASE-RXN]

Retinol O-fatty-acyltransferase (ROFAT) activity is a crucial enzymatic process involved in the esterification of retinol (vitamin A) with fatty acids. This reaction results in the formation of retinyl esters, which are the primary storage form of vitamin A in the body.

ROFAT enzymes catalyze the transfer of a fatty acyl group from a fatty acyl-CoA donor to the hydroxyl group of retinol. This process occurs in various tissues, including the liver, intestines, and adipose tissue.

The molecular function of ROFAT activity plays a vital role in maintaining vitamin A homeostasis:

1. **Storage and mobilization of vitamin A:** Retinyl esters produced by ROFAT activity are stored in lipid droplets, primarily within the liver. When retinol levels are low, these esters are hydrolyzed by retinyl ester hydrolases, releasing retinol for utilization.

2. **Absorption and transport of vitamin A:** ROFAT enzymes in the intestinal mucosa are essential for the absorption and transport of dietary retinol. After dietary retinol is absorbed, it is rapidly esterified by ROFAT, which facilitates its packaging into chylomicrons and subsequent transport to the liver.

3. **Tissue-specific distribution of vitamin A:** ROFAT activity also contributes to the specific distribution of retinoids to different tissues. For instance, in the retina, ROFAT activity is involved in the production of 11-cis-retinal, the light-absorbing chromophore essential for vision.

4. **Regulation of vitamin A metabolism:** The activity of ROFAT enzymes is tightly regulated by various factors, including retinol levels, hormonal signals, and dietary fatty acid composition. This ensures that vitamin A levels are maintained within a safe and functional range.

In summary, retinol O-fatty-acyltransferase activity plays a critical role in maintaining vitamin A homeostasis by facilitating its storage, mobilization, absorption, transport, and tissue-specific distribution. It is a crucial enzymatic process that ensures adequate availability of this essential nutrient for various physiological functions.'
"

Proteins (2)

Compounds (6)