Carboxyl terminal sequence of human phospholipase C gamma 2

Phospholipase C gamma2 (PLC gamma2), the predominant isoform of phospholipa se C expressed in platelets, plays a major role in activation of platelets by collagen. Although PLC gamma2 has been shown to be tyrosine phosphorylat ed upon collagen-induced activation, the phosphorylation sites are yet to b e determined. We have sequenced the 3' terminal cDNA of human phospholipase C-gamma-2 and found it different from the human PLC gamma2 cDNA sequence p reviously reported by Ohta et al, (Ohta S, Matsui A, Nazawa Y, Kagawa Y, FE ES Lett 1988; 242: 31-5), There is an extra guanosine at position 3723 whic h causes a shift in the reading frame. The new carboxyl terminal amino acid (aa) sequence beyond the frame shift is 88% identical to that of rat (21 o ut of 24 aa residues) which is considerably higher than the identity with p ublished sequence (26% identity), The new deduced aa sequence contains two tyrosine residues at positions 1245 and 1264 which might be phosphorylated upon stimulation and hence might be important for the activation of the PLC gamma2.