glycerol-3-phosphate O-acyltransferase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: acyl-CoA + sn-glycerol 3-phosphate = CoA + 1-acyl-sn-glycerol 3-phosphate. [EC:2.3.1.15]

Glycerol-3-phosphate O-acyltransferase (GPAT) activity is a critical step in the synthesis of triglycerides, the major form of energy storage in animals. GPAT catalyzes the transfer of a fatty acyl group from a fatty acyl-CoA molecule to sn-glycerol 3-phosphate (G3P), forming lysophosphatidic acid (LPA). This reaction is the first committed step in glycerolipid biosynthesis, and it occurs in the endoplasmic reticulum (ER) of cells.

GPAT activity is highly regulated, and it is influenced by factors such as the availability of substrates, the hormonal environment, and dietary factors. Different isoforms of GPAT exist in various tissues and subcellular compartments, each with its own unique substrate specificity and regulatory mechanisms.

The molecular mechanism of GPAT activity involves the following steps:

1. **Binding of substrates**: GPAT binds to both G3P and a fatty acyl-CoA molecule. The binding site for G3P is typically located near the active site, while the binding site for fatty acyl-CoA can be located at a different site.
2. **Formation of a reactive intermediate**: The fatty acyl group is transferred from the fatty acyl-CoA molecule to a cysteine residue in the active site of GPAT.
3. **Acyl transfer to G3P**: The fatty acyl group attached to the cysteine residue in the active site is transferred to the sn-1 position of G3P, forming LPA.
4. **Release of products**: LPA and CoA are released from the enzyme, completing the reaction cycle.

GPAT activity is essential for the synthesis of triglycerides, which play a vital role in energy storage, membrane structure, and lipid signaling. Dysregulation of GPAT activity has been implicated in various diseases, including obesity, diabetes, and cardiovascular disease.'
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Proteins (1)

Compounds (3)