PLC-gamma1 plays an important role in transducing the external signal in to second messengers by hydrolysing PIP2. PLC-gamma1 contains an N-term PH domain, a catalytic domain 'X' followed by two SH2 domains and an SH3 domain, a C-term catalytic domain 'Y' and a C2 domain (Ca++ binding). PLC-gamma1 interacts with both SLP-76 aswell as LAT. It interacts with its SH3 domain to the proline rich sequence of SLP-76. This interaction aids in localizing PLC-gamma1 to the membrane. This recruitment of PLC-gamma1 to LAT and SLP-76 is essential for its TCR induced tyrosine phosphorylation and activation.