Immunoreceptor tyrosine-based inhibitory motif

An immunoreceptor tyrosine-based inhibition motif (ITIM), is a conserved sequence of amino acids (S/I/V/LxYxxI/V/L) that is found in the cytoplasmic tails of many inhibitory receptors of the immune system. After ITIM-possessing inhibitory receptors interact with their ligand, their ITIM motif becomes phosphorylated by enzymes of the Src kinase family, allowing them to recruit other enzymes such as the phosphotyrosine phosphatases SHP-1 and SHP-2, or the inositol-phosphatase called SHIP. These phosphatases decrease the activation of molecules involved in cell signaling.^[1] A list of human candidate ITIM-containing proteins has been generated by proteome-wide scans. ^[2]

References

1. Barrow A, Trowsdale J (2006). "You say ITAM and I say ITIM, let's call the whole thing off: the ambiguity of immunoreceptor signaling". Eur J Immunol 36 (7): 1646–53. doi:10.1002/eji.200636195. PMID 16783855.
2. Staub E, Rosenthal A, Hinzmann B (2004). "Systematic identification of immunoreceptor tyrosine-based inhibitory motifs in the human proteome". Cell Signal 16 (4): 435–456. doi:10.1016/j.cellsig.2003.08.013. PMID 14709333.