ARAM motif

The T and B cell antigen receptors do not have any intrinsic protein tyrosine kinase activity. Rather, antigen binding leads to recruitment and activation of protein tyrosine kinases on the cytoplasmic side of the receptor. Probably, coupling of the tyrosine kinase takes place via the ARAM motif directly. 

In this reaction chain, ZAP kinase performs an essential function. Tlie phosphorylated ARAM motives recruit ZAP70 kinase to the T cell receptor complex and mediate high affinity binding to the kinase. The two SH2 domains of ZAP70 kinase bind in tandem fashion to the twice-phosphorylated ARAM motif ZAP70 kinase shows a complex pattern of Tyr phosphorylation, including phosphorylations with an inhibitory effect. 

ARAM motif antigen recognition and activation motif... 

Fig. 11.9. Subunit structure of the T cell receptors. The figure shows the different subunits of T cell receptors in a highly simplified representation. The stoichiometry of the subunits in the complete receptor is not clear. The aP chains are also known as the TiaP complex the ye and 8e chains together form the CDS complex. ARAM antigen recognition activation motif...

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