Angiotensin Il-Induced binding of the at₁ receptor with phospholipast1 C-γ

Angiotensin II (Ang II), acting via its G protein-linked AT₁, receptor, induces the tyrosine phosphorylation and activation of phospholipase (PLC)-yl- In this study we show that both the AT, receptor itself and a glutathione S-transferase (GST) fusion protein containing the cytoplasmic, carboxyl-termina) 54 amino acids of the AT, receptor physically binds to PLC-yl in an Ang Il-dependent manner. Amino acid dcletional analysis and peptide competition experiments show that this association is dependent on tyrosine residue J1Y and the "''YIPP motif in the carboxyl-terminal tail of the AT, receptor and the carboxyl-terminal SH2 domain of PLC-yl. These results support the concept that G protein-linked receptors can physically associate with intracellular proteins, creating membrane-delimited signal transduction complexes in a manner similar to that observed with classic growth factor receptors.