Multicellular organisms use chemical messengers to\r<br />transmit signals among organelles and to other cells. Relatively small hydrophobic molecules such as lipids\r<br />are excellent candidates for this signaling purpose. In most proteins, palmitic\r<br />acid and other saturated and some unsaturated fatty acids are esterified to the\r<br />free thiol of cysteines and to the N-amide terminal. This palmitoylation\r<br />process enhances the surface hydrophobicity and membrane affinity of protein\r<br />substrates and plays important roles in modulating proteins’ trafficking, stability, and sorting\r<br />etc. Protein palmitoylation has been involved in numerous cellular processes,\r<br />including signaling, apoptosis, and neuronal transmission. The palmitoylation\r<br />process is involved in multiple diseases such as Huntington’s disease, various\r<br />cardiovascular and T-cell mediated immune disorders, as well as cancer. Protein\r<br />palmitoylation through the thioester (S-acylation) is unique in that it is the only\r<br />reversible lipid modification. Our study on lipopolysaccharide (LPS) and\r<br />deoxynivalenol (DON) treatment to rats provides some insights to the complex role of protein palmitoylation in\r<br />chemical and microbial toxicity. In contrast, myrisoylated proteins\r<br />contain the 14-carbon fatty acid myristate attached via amide linkage to the\r<br />N-terminal glycine residue of protein, and occur cotranslationally. The\r<br />bacterial outer membrane enzyme lipid A palmitoyltransferase (PagP) confers\r<br />resistance to host immune defenses by transferring a palmitate chain from a\r<br />phospholipid to the lipid A component of LPS. PagP is sensitive to cationic\r<br />antimicrobial peptides (CAMP) which are included among the products of the\r<br />Toll-like receptor 4 (TLR4) signal transduction pathway. This modification of\r<br />lipid A with a palmitate appears to both and protects the pathogenic bacteria\r<br />from host immune defenses and attenuates the activation of those same defenses\r<br />through the TLR4 signal transduction pathway.
Kim, C. S., & Ross, I. A. (2013). Regulatory Role of Free Fatty Acids (FFAs)—Palmitoylation and Myristoylation. Food and Nutrition Sciences, 04(09), 202–211. https://doi.org/10.4236/fns.2013.49a1028