Palmitoyl acyltransferase is a group of

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

s that transfer palmityl group to -SH group on

cysteine Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. When present as a deprotonated catalytic residue, sometime ...

on a protein. This modification increases the hydrophobicity of the protein, thereby increasing the association to plasma membrane or other intramembraneous compartments.

Domain structure

The palmitoyl acyltransferase was isolated and identified in 1999. The catalytic domain of the protein has aspartate-histidine-histidine-cysteine (DHHC) in the core and therefore is called

DHHC domain In molecular biology the DHHC domain is a protein domain that acts as an enzyme, which adds a palmitoyl chemical group to proteins in order to anchor them to cell membranes. The DHHC domain was discovered in 1999 and named after a conserved sequ ...

Substrate proteins

The example of substrate includes H-Ras, N-ras, R-Ras, RhoB, Cdc42 inform 2, Rab10, Galpha subunit of trimeric GTP binding proteins, Src family tyrosine kinases, GAP53, eNOS, AMPA receptor subunit GluR1 and GluR2, GABA_A receptor gamma2 subunit, aquaporin, KV1.1, rhodopsin, beta2-adrenergic receptor, and PSD-95. https://swisspalm.org/enzymes

Physiological Functions

The protein palmitoylation is a reversible process. The addition of palmitoyl group increase the membrane association of the substrate protein while the removal by palmitoyl thioesterase decreases the membrane association.

References

* * {{Portal bar, Biology, border=no Post-translational modification Carcinogenesis EC 2.3.1