Choline metabolism pathway

The **choline metabolism pathway** refers collectively to a network of biochemical reactions involving the uptake, utilization, transformation, and breakdown of choline within cells. This includes three major branches: 1. **Oxidation:** Choline is oxidized to betaine in the liver. Betaine donates methyl groups for remethylation of homocysteine to methionine—critical for S‐adenosylmethionine production and global methylation reactions affecting DNA/RNA/protein modification[1][5]. 2. **Phosphorylation:** Via the Kennedy/CDP-choline pathway and PEMT route, choline is converted into phosphatidylcholine—a key component of cell membranes—and other related lipids essential for lipid transport/packaging (e.g., VLDL assembly), membrane integrity, signaling molecules generation (e.g., diacylglycerol), and cell division[1][3][5]. 3. **Acetylation:** In neurons especially but also non-neuronal cells throughout the body, acetyl-CoA combines with choline via choline acetyltransferase to form acetylcholine—a neurotransmitter vital for muscle control and cognitive function[5]. Abnormalities in this metabolic network are implicated in several diseases—most notably cancer where upregulation of certain enzymes like *chokine kinase alpha* leads to increased membrane precursor pools supporting rapid tumor growth; nonalcoholic fatty liver disease due to impaired lipid export from hepatocytes; cardiovascular risk through altered methyl group balance; emerging links with obesity have also been proposed[2][4]. **Note on Target Validity:** The "choline metabolism pathway" itself is not a single molecular target but rather an umbrella term encompassing multiple distinct enzymatic targets such as *chokine kinase alpha*, *phosphatidylethanolamine N-methyltransferase*, etc.[2]. Therefore, this entry is marked as **is_incorrect = true**, because it does not refer specifically enough to an actionable therapeutic target or molecule. For structured drug discovery or mechanistic studies, it is necessary to specify which enzyme or transporter within this broad metabolic framework is being targeted—for example, "Choline kinase alpha" rather than "Choline metabolism pathway"[2]. Mechanisms of action for drugs are specific to individual enzymes or steps within the pathway (e.g., inhibition of choline kinase alpha impairs phosphocholine production and cell proliferation[2][4]). No drugs directly target the entire "choline metabolism pathway" as a single entity; drugs target specific enzymes in this pathway, such as choline kinase inhibitors. Safety concerns relate to modulation of individual enzymes or metabolites; excessive dietary choline can cause side effects such as fishy body odor, hypotension, and increased TMAO linked to cardiovascular risk[7].

Other names

Choline metabolic pathwayCholine biosynthesis and degradationKennedy pathway (for the CDP-choline branch)PEMT pathway (for phosphatidylethanolamine N-methyltransferase branch)