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Palmitoylation

S-Palmitoylation is the covalent attachment of fatty acids, such as palmitic acid, to cysteine residues of membrane proteins.[1]

The precise function of palmitoylation depends on the particular protein being considered. Palmitoylation enhances the hydrophobicity of proteins and contributes to their membrane association. Palmitoylation also appears to play a significant role in subcellular trafficking of proteins between membrane compartments, as well as in modulating protein-protein interactions.[2]In contrast to prenylation and myristoylation, palmitoylation is reversible. This allows the cell to dynamically regulate the location of specific proteins.

An example of a protein that undergoes palmitoylation is hemagglutinin, a membrane glycoprotein used by influenza to attach to host cell receptors. [3]

Because S-palmitoylation is a dynamic, post-translational process, it is believed to be employed by the cell to alter the subcellular localization, protein-protein interactions, or binding capacities of a protein.

The palmitoylation cycles of a wide array of enzymes have been characterized in the past few years, including H-Ras, Gsα, the β2-adrenergic receptor, and endothelial nitric oxide synthase (eNOS).

 Palmitoylation in Synaptic Plasticity

Recently, scientists have appreciated the significance of attaching long hydrophobic chains to specific proteins in cell signaling pathways. A good example of its significance is in the clustering of proteins in the synapse. A major mediator of protein clustering in the synapse is the postsynaptic density (95kD) protein, PSD-95. When this protein is palmitoylated it is restricted to the membrane. This restriction to the membrane allows it to bind to and cluster ion channels in the postsynaptic membrane. Also, in the presynaptic neuron, palmitoylation of SNAP-25 allows the SNARE complex to dissociate during vesicle fusion. This provides a role for palmitoylation in regulating neurotransmitter release.[4]

 See also

 References

  1. ^ Linder, M.E., "Reversible modification of proteins with thioester-linked fatty acids," Protein Lipidation, F. Tamanoi and D.S. Sigman, eds., pp. 215-40 (San Diego, CA: Academic Press, 2000).
  2. ^ Basu, J., "Protein palmitoylation and dynamic modulation of protein function," Current Science, Vol. 87, No. 2, pp. 212-17 (25 July 2004), http://www.ias.ac.in/currsci/jul252004/contents.htm
  3. ^ influenza viruses, the encyclopedia of virology, http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B7GG4-4CK7DHD-S&_rdoc=5&_hierId=42642&_refWorkId=141&_explode=42642&_alpha=I&_fmt=full&_orig=na&_docanchor=&_idxType=AR&view=c&_ct=10&_acct=C000011279&_version=1&_urlVersion=0&_userid=5399531&md5=607bbb1a7d18138457365550b9471eb5.
  4. ^ "Molecular Mechanisms of Synaptogenesis." Edited by Alexander Dityatev and Alaa El-Husseini. Springer: New York, NY. 2006. pg. 72-75

 

The content of this section is licensed under the GNU Free Documentation License (local copy). It uses material from the Wikipedia article "Palmitoylation" modified November 23, 2009 with previous authors listed in its history.