How to Learn Protein N-Myristoylation: From NMT1/NMT2 and Myristoyl-CoA to Membrane Targeting, Myristoyl Switches and Lipidation Proteomics

Quick Read. N-myristoylation is a lipid modification that attaches a 14-carbon myristoyl group to selected proteins, usually at an exposed N-terminal glycine. The modification is installed by N-myristoyltransferases NMT1 and NMT2 using myristoyl-CoA. It often helps proteins associate with membranes, but the important idea is not “fat makes proteins sticky.” Myristate is one part of a conditional targeting system that can work together with electrostatics, protein conformation, phosphorylation, partner binding and proteolysis.

One-sentence answer: learn N-myristoylation as a sequence — expose the right amino group → load myristoyl-CoA into NMT → transfer myristate → combine the lipid with other molecular signals → test whether localisation and function actually change.

Wait, what? A tiny lipid can change where a protein lives

A protein can contain hundreds of amino acids, yet adding one small lipid near its beginning can change which membrane it approaches, which partners it meets and which signals it can transmit. That sounds disproportionate until you remember that cells are spatial machines. A reaction that happens on the plasma membrane is not equivalent to the same reaction in the cytosol. Location changes access.

This is why N-myristoylation is best learned as a routing modification, not as a decorative chemical detail. The lipid does not usually determine the destination by itself. Instead it changes the probability that a protein will occupy particular membrane environments, especially when a second signal — often a cluster of basic residues, a conformational switch or another lipid modification — helps stabilise the interaction.

Stage 1 — Beginner: what is being attached?

Myristic acid is a saturated 14-carbon fatty acid. During N-myristoylation, the myristoyl group is covalently attached through an amide bond to an amino group on a protein. The classic case is the alpha-amino group of glycine at the protein’s N-terminus. In many proteins, the initiator methionine is removed first, exposing Gly2 as the new N-terminal residue.

The donor is not free myristic acid. Cells use myristoyl-CoA. The CoA thioester activates the acyl group so that NMT can transfer it to the substrate. This immediately connects the topic to Coenzyme A metabolism and compartmentation: lipid modification depends on the cell having the right activated acyl donor in the right biochemical context.

Stage 2 — Secondary to pre-university: the enzyme reads more than one amino acid

A common beginner mistake is to memorise “glycine at position 2 means myristoylation.” It does not. An N-terminal glycine is often necessary for conventional N-myristoylation, but it is not sufficient. NMT recognises a short sequence and three-dimensional chemical environment around the N-terminus. Different neighbouring residues make a candidate better or worse as a substrate.

Human cells contain two related enzymes, NMT1 and NMT2. Both transfer myristate, but they are not simply interchangeable copies. Their expression, localisation, substrate preferences and biological contributions can differ. NMT1 is especially important in many basal cellular contexts, while NMT2 can contribute distinct substrate relationships. Current structural work has also sharpened our understanding of how human NMT engages the translation machinery during co-translational modification.

The most useful reaction map is:

• an appropriate N-terminus becomes available;
• NMT binds myristoyl-CoA;
• the substrate peptide enters the catalytic site;
• the myristoyl group is transferred;
• CoA and the myristoylated protein leave;
• the modified protein enters a new localisation and interaction landscape.

Stage 3 — Advanced learning: co-translational and post-translational routes

Most textbook explanations emphasise co-translational N-myristoylation. The nascent chain emerges from the ribosome, the initiator methionine is removed when the sequence permits, Gly2 is exposed and NMT modifies the young protein while translation is still in progress.

But N-myristoylation can also occur post-translationally. Proteolysis can expose an internal glycine that becomes a new N-terminus. Caspase cleavage during apoptosis provides classic examples. BID, actin, gelsolin and PAK2 illustrate the broader principle: proteolysis can reveal a hidden lipidation site, converting cleavage into a localisation switch.

This gives an important reasoning chain:

protease cleavage → new N-terminus → possible NMT substrate → lipidation → changed membrane access → changed signalling consequence

That chain is more useful than memorising individual examples because it transfers to unfamiliar proteins.

The myristoyl switch: why the lipid is often conditional

One myristoyl chain provides limited membrane-binding energy. Many proteins therefore use a second control. In a myristoyl switch, the lipid can be more exposed or more buried depending on protein conformation, ligand binding, nucleotide state, calcium binding or phosphorylation. A protein can therefore carry the same covalent lipid while changing how strongly that lipid participates in membrane binding.

This corrects another misconception: covalent modification does not mean fixed behaviour. The lipid is permanent on that protein molecule, but its functional accessibility can be regulated.

Membrane targeting is a two-factor problem

Many myristoylated proteins combine the lipid with electrostatic attraction. Negatively charged phospholipids in a membrane can interact with positively charged amino-acid clusters on the protein. The myristate inserts into the bilayer while basic residues help hold the protein near the surface. This is sometimes called a “myristoyl-electrostatic switch.”

This connects directly to phosphoinositides and membrane identity. A protein does not merely ask “is there a membrane?” It effectively encounters a membrane with a particular lipid composition, charge, curvature and set of binding partners.

Professional level — the modification is broader than the classic rule

The mature professional model needs two caveats. First, NMT biology includes more than alpha-amino myristoylation of glycine. Structural and biochemical studies have shown that mammalian NMTs can also catalyse lysine myristoylation in particular contexts, including ARF6 regulation. Second, the mere presence of a chemically plausible site does not establish physiological modification. Sequence prediction must be tested against experiments.

That distinction matters because modern proteomics can produce long candidate lists. A strong claim should separate: predicted site, chemically detected modification, enzyme dependence, stoichiometry, localisation consequence and organism-level function.

How scientists know: evidence ladder

• Biochemistry: purified NMT, myristoyl-CoA and substrate peptides establish catalytic capability.
• Structural biology: enzyme–substrate structures reveal how donor and peptide are positioned.
• Metabolic labelling: myristate analogues can be incorporated into proteins and enriched using click chemistry.
• Mass spectrometry: modified peptides can be identified and mapped.
• Genetics: NMT depletion or substrate Gly-to-Ala mutation tests enzyme/site dependence.
• Cell imaging: localisation can be compared before and after loss of myristoylation.
• Functional rescue: the strongest experiments ask whether restoring the modification restores the phenotype.

Proteomic approaches using clickable myristate analogues are powerful, but they have limits. Labelling efficiency, metabolic conversion, abundance, extraction and mass-spectrometric detectability can bias the observed “myristoylome.” Absence from a dataset is therefore not proof that a protein is never myristoylated.

Current evidence and freshness check

This topic was reviewed against current sources through September 2026. A 2026 structural study in Nature Communications reported new detail on the structural basis of co-translational N-myristoylation in humans, strengthening the ribosome-coupled model. Clinical interest is also active: a 2024 first-in-human phase I study of the dual NMT1/NMT2 inhibitor zelenirstat reported tolerability and early antitumour signals, while antiviral work has continued into 2025. These findings are useful as evidence that NMT is biologically and pharmacologically important, but they do not mean NMT inhibition is an established general cancer or antiviral treatment.

Misconceptions to remove

• “Every Gly2 protein is myristoylated.” False. Local sequence, structure, enzyme access and cell context matter.
• “Myristoylation anchors proteins permanently to membranes.” Often false. Membrane association can remain dynamic and conditional.
• “It only happens while proteins are being made.” False. Protease-generated N-termini can be post-translationally myristoylated.
• “The lipid alone tells you which membrane.” Usually false. Charge, partner proteins and membrane composition contribute.
• “A predicted site proves modification.” False. Prediction is a hypothesis, not a measurement.

Model limits: what a simple diagram hides

A simple diagram showing “protein + myristate = membrane protein” hides at least five variables: substrate sequence, NMT isoform, myristoyl-CoA supply, accessibility of the lipid after modification, and membrane composition. It also ignores competition between membrane binding and soluble partners. At professional level, think probabilistically: myristoylation shifts the energy landscape and interaction possibilities rather than assigning one irreversible address.

Transfer checks

• A protein has Gly2 but remains cytosolic after expression. Give three reasons why.
• A caspase exposes a new glycine during apoptosis. What evidence would show that the cleavage product is post-translationally myristoylated?
• A Gly-to-Ala mutation removes membrane localisation. Why is that suggestive but not yet complete proof of mechanism?
• A myristoylated protein moves off the membrane after phosphorylation. Explain how this can happen without removing the lipid.
• Why might two cell types show different localisation for the same myristoylated protein?

Beginner-to-professional learning route

Beginner: know myristate, Gly2, NMT and membrane association. Intermediate: add myristoyl-CoA, methionine removal, sequence specificity and two-factor membrane binding. Advanced: compare co-translational and post-translational routes, myristoyl switches and proteomic evidence. Professional: analyse enzyme isoforms, structural mechanism, non-classical lysine myristoylation, pharmacology, assay bias and causal evidence.

Evidence sources for further study

• Structural basis of co-translational N-myristoylation in humans (2026)
• Protein lipidation in health and disease: molecular basis, physiological function and pathological implication
• NMT1 and NMT2 are lysine myristoyltransferases regulating the ARF6 GTPase cycle
• First-in-human phase I trial of zelenirstat
• Posttranslational N-myristoylation of BID

The strongest understanding comes when you can predict what evidence would change your mind. In N-myristoylation, chemistry, localisation and function are connected, but they are not the same claim. Learn to test each link separately.