protein-cysteine S-stearoyltransferase activity

Definition

Target type: molecularfunction

Catalysis of the transfer of a stearoyl (systematic name, octadecanoyl) group to a sulfur atom on the cysteine of a protein molecule, in the reaction: octadecanoyl-CoA + L-cysteinyl-[protein] = CoA + S-octadecanoyl-L-cysteinyl-[protein]. [PMID:12681491, PMID:22247542, PMID:22968831, RHEA:59740]

Protein-cysteine S-stearoyltransferase activity is a critical molecular function involved in the covalent attachment of stearic acid, a saturated fatty acid, to cysteine residues within proteins. This process, known as S-stearoylation, is a type of protein palmitoylation, a reversible post-translational modification that plays a crucial role in regulating protein function, localization, and interactions.

The enzymes responsible for this activity are known as S-stearoyltransferases. These enzymes catalyze the transfer of stearic acid from a donor molecule, typically coenzyme A (CoA), to the sulfhydryl group of a cysteine residue within a target protein. The reaction involves the formation of a thioester bond between the stearic acid and the cysteine residue.

S-stearoylation, like other forms of protein palmitoylation, can alter the properties of target proteins in several ways:

- **Localization:** S-stearoylation can promote the association of proteins with membranes, particularly the plasma membrane. This is due to the hydrophobic nature of the stearic acid moiety, which anchors the protein to the lipid bilayer.
- **Stability:** S-stearoylation can enhance the stability of certain proteins, preventing their degradation.
- **Activity:** S-stearoylation can modulate the activity of proteins by influencing their interactions with other molecules, including other proteins, lipids, and signaling molecules.

S-stearoylation is implicated in a wide range of cellular processes, including:

- **Signal transduction:** S-stearoylation regulates the activity of signaling proteins involved in various pathways, such as G protein-coupled receptor signaling and growth factor signaling.
- **Vesicle trafficking:** S-stearoylation plays a role in the targeting and fusion of vesicles, which are membrane-bound sacs that transport molecules within cells.
- **Cell adhesion:** S-stearoylation is involved in the formation and maintenance of cell-cell and cell-matrix junctions, which are essential for tissue structure and function.

Dysregulation of S-stearoylation has been linked to various diseases, including cancer, neurodegenerative disorders, and metabolic diseases. Further research into the mechanisms and functions of S-stearoylation is ongoing, with the aim of developing novel therapeutic strategies targeting this important post-translational modification.'
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Proteins (1)

Compounds (1)