CD8

Studies have shown that a chimeric CD8A containing the TMH of another protein, such as the interleukin-2 receptor, exhibits a significantly reduced dimeric form.

Together with a Zn²⁺ ion and two cysteines (Cys20 and Cys23) from Lck, these residues help position the kinase near the TCR to phosphorylate the ITAM regions of CD3 subunits.

Palmitoylation is crucial for targeting proteins to specialized membrane regions, including lipid rafts and immunological synapses.

For CD8, palmitoylation facilitates the recruitment of Lck bound to CD8 to the immunological synapse, enhancing proximity to the ITAM regions of CD3 and promoting efficient TCR signaling.

[4] The first crystal structure of the deglycosylated IgV domain of the CD8A molecule was published by Leahy, DJ, Axel, R, and Hendrickson, WA in 1992.

[2] The extracellular immunoglobulin-like domain of CD8 monomers adopts a typical IgV fold, composed of two beta sheets (strands ABED and A'G'GFCC'C'').

The cytoplasmic tail of the CD8 co-receptor bind Lck (lymphocyte-specific protein tyrosine kinase) via common Cys4-Zn finger.