Page last updated: 2024-10-24

N-terminal protein myristoylation

Definition

Target type: biologicalprocess

The covalent attachment of a myristoyl group to the N-terminal amino acid residue of a protein. [GOC:mah]

N-terminal protein myristoylation is a type of lipid modification that plays a crucial role in cellular signaling and membrane association. It involves the covalent attachment of myristate, a 14-carbon saturated fatty acid, to the N-terminal glycine residue of a protein. The process is catalyzed by N-myristoyltransferase (NMT), a highly conserved enzyme present in all eukaryotic organisms.

Myristoylation typically occurs co-translationally, meaning it happens while the protein is being synthesized. The N-terminal glycine residue of the nascent polypeptide chain is exposed as the ribosome translocates the mRNA. NMT recognizes a specific amino acid sequence motif, often referred to as a "myristoylation signal," near the N-terminus of the protein. This motif typically consists of a glycine residue followed by a small hydrophobic amino acid, such as alanine, serine, or cysteine.

Once NMT binds to the target protein, it catalyzes the transfer of myristate from myristoyl-CoA, a coenzyme, to the N-terminal glycine residue. This reaction forms an amide bond between the carboxyl group of myristate and the amino group of glycine. The myristoylated protein is then released from NMT and can associate with cellular membranes.

Myristoylation is a highly specific and irreversible modification. It is essential for the proper function of a wide range of proteins, including:

* **Signal transduction proteins:** Myristoylation often targets proteins involved in signal transduction pathways, such as Src kinases and Ras GTPases. Myristate anchors these proteins to the plasma membrane, bringing them into close proximity with their signaling partners.
* **Membrane-associated proteins:** Many proteins that function at the cell membrane, such as G-protein coupled receptors and ion channels, are myristoylated. Myristoylation helps these proteins to associate with the lipid bilayer and perform their roles.
* **Viral proteins:** Some viral proteins, including the matrix protein of HIV-1, are myristoylated. This modification is essential for viral assembly and budding from host cells.

Myristoylation plays a critical role in regulating protein localization, activity, and interactions. It is a dynamic process that can be influenced by various cellular factors, including phosphorylation, ubiquitination, and other post-translational modifications. The study of N-terminal protein myristoylation continues to reveal important insights into the diverse functions of this lipid modification in cellular processes.'
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Proteins (3)

ProteinDefinitionTaxonomy
Glycylpeptide N-tetradecanoyltransferase 1A glycylpeptide N-tetradecanoyltransferase 1 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P30419]Homo sapiens (human)
Protein phosphatase 1AA protein phosphatase 1A that is encoded in the genome of human. [PRO:DNx, UniProtKB:P35813]Homo sapiens (human)
Protein phosphatase 1BA protein phosphatase 1B that is encoded in the genome of human. [PRO:DNx, UniProtKB:O75688]Homo sapiens (human)

Compounds (7)

CompoundDefinitionClassesRoles
cantharidincantharidin : A monoterpenoid with an epoxy-bridged cyclic dicarboxylic anhydride structure secreted by many species of blister beetle, and most notably by the Spanish fly, Lytta vesicatoria. Natural toxin inhibitor of protein phosphatases 1 and 2A.

Cantharidin: A toxic compound, isolated from the Spanish fly or blistering beetle (Lytta (Cantharis) vesicatoria) and other insects. It is a potent and specific inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A). This compound can produce severe skin inflammation, and is extremely toxic if ingested orally.
cyclic dicarboxylic anhydride;
monoterpenoid
EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor;
herbicide
cyanoginosin lrcyanoginosin LR: cyclic heptapeptide from cyanobacterium Microcystis aeruginosa

microcystin-LR : A microcystin consisting of D-alanyl, L-leucyl, (3S)-3-methyl-D-beta-aspartyl,L-arginyl, 2S,3S,4E,6E,8S,9S)-3-amino-4,5,6,7-tetradehydro-9-methoxy-2,6,8-trimethyl-10-phenyldecanoyl, D-gamma-glutamyl, and 2,3-didehydro-N-methylalanyl residues joined into a 25-membered macrocycle. Produced by the cyanobacterium Microcystis aeruginosa, it is the most studied of the microcystins.
microcystinbacterial metabolite;
EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor;
environmental contaminant;
xenobiotic
sc 58272SC 58272: inhibits myristoyl-CoA:protein N-myristoyltransferase; structure given in first source
maleic acid anilidemaleic acid anilide: structure given in first source
cyanoginosin-lacyanoginosin-LA: from cyanobacterium Microcystis aeruginosapeptide
demethylcantharidindemethylcantharidin: has antineoplastic activity; structure in first source
ddd 85646DDD 85646: a trypanocidal agent for treating African sleeping sickness; structure in first source