Catalytic domain of metazoan phospholipase C related, but catalytically inactive protein
This family corresponds to the catalytic domain present in metazoan phospholipase C related, but catalytically inactive proteins (PRIP), which belong to a group of novel Inositol 1,4,5-trisphosphate (InsP3) binding protein. PRIP has a primary structure and domain architecture, incorporating a pleckstrin homology (PH) domain, an array of EF hands, a PLC catalytic core domain with highly conserved X- and Y-regions split by a linker sequence, and a C-terminal C2 domain, similar to phosphoinositide-specific phospholipases C (PI-PLC, EC 184.108.40.206)-delta isoforms. Due to replacement of critical catalytic residues, PRIP do not have PLC enzymatic activity. PRIP consists of two subfamilies, PRIP-1(previously known as p130 or PLC-1), which is predominantly expressed in the brain, and PRIP-2 (previously known as PLC-2), which exhibits a relatively ubiquitous expression. Experiments show both, PRIP-1 and PRIP-2, are involved in InsP3-mediated calcium signaling pathway and GABA(A)receptor-mediated signaling pathway. In addition, PRIP-2 acts as a negative regulator of B-cell receptor signaling and immune responses.