Resolution of a signal transfer region from a general binding domain in G beta for stimulation of phospholipase C-beta 2

Signaling by guanine nucleotide-binding proteins (G proteins) involves sequ ential protein-protein interactions. G protein-beta gamma subunit (G beta g amma) interactions with phospholipase C-beta 2 (PLC-beta 2) were studied to determine if all G beta contacts are required for signaling. A peptide enc oding G beta amino acid residues 86 to 105 stimulated PLC-beta 2. Six resid ues (96 to 101) within this sequence could transfer signals and thus consti tute a core signal transfer region. Another peptide, encoding G beta amino acid residues 115 to 135, did not substantially stimulate PLC-beta 2 by its elf but inhibited G beta gamma stimulation, indicating that residues 115 to 135 constitute a general binding domain. Resolution of signal transfer reg ions from general binding domains indicates that all protein-protein contac ts are not required for signal transfer and that it may be feasible to synt hesize agonists and antagonists that regulate intracellular signal flaw.