TCR Signaling Pathway

T cell receptor is a complex of antigen specific alpha and beta chains associated in membrane CD3 gamma and CD3 delta,epsilon and zeta chains .

Each of the cd3 chains have at lest one copy of signaling motif immunoreceptor tyrosine activation motif or ITAMs in the cytoplasmic domain .various short family tyrosine kinase will associate with cytoplasmic domains in the Tcell receptor complex.

Fyn along with other short kinase family members are important for t cell activation,other molecules involved in T cell activation includes CD45 whose cytoplasmic domain contains tyrosine phosphatase enzyme and the T cell co receptor either CD4 or CD8.In this example the co receptor is CD4 ,the co receptor molecules have bound to cytoplasmic domains tyrosine kinase Lck,the cytosol enzyme ZAP70 also plays a essential role t cell activation.