General and versatile autoinhibition of PLC isozymes
Hicks, S.N., Jezyk, M.R., Gershburg, S., Seifert, J.P., Harden, T.K., Sondek, J.(2008) Mol Cell 31: 383-394
- PubMed: 18691970 
- DOI: https://doi.org/10.1016/j.molcel.2008.06.018
- Primary Citation of Related Structures:  
2ZKM - PubMed Abstract: 
Phospholipase C (PLC) isozymes are directly activated by heterotrimeric G proteins and Ras-like GTPases to hydrolyze phosphatidylinositol 4,5-bisphosphate into the second messengers diacylglycerol and inositol 1,4,5-trisphosphate. Although PLCs play central roles in myriad signaling cascades, the molecular details of their activation remain poorly understood. As described here, the crystal structure of PLC-beta2 illustrates occlusion of the active site by a loop separating the two halves of the catalytic TIM barrel. Removal of this insertion constitutively activates PLC-beta2 without ablating its capacity to be further stimulated by classical G protein modulators. Similar regulation occurs in other PLC members, and a general mechanism of interfacial activation at membranes is presented that provides a unifying framework for PLC activation by diverse stimuli.
Organizational Affiliation: 
Department of Pharmacology, The University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.