The present invention relates to a binding motif of a receptor. In particular, the binding motif is a cytoplasmic domain associated with stimulation of receptor mediated activities. The present invention further contemplates methods of using the motif in particular for mediating activities of receptors. In one aspect of the present invention, there is provided a binding motif of a receptor capable of binding a cytoplasmic protein, said binding motif comprising an amino acid sequence wherein at least one amino acid is serine/threonine preferably there are at least two serines to indicate the cytoplasmic binding motif. Preferably the binding motif comprises an amino acid sequence including the sequence: -S-X-S/T- wherein the X is any amino acid.