PIP2 and Proteins: Interactions, Organization, and Information Flow

Stuart McLaughlin, Jiyao Wang, Alok Gambhir, Diana Murray
2002 Annual Review of Biophysics and Biomolecular Structure  
Key Words phosphatidylinositol 4,5-bisphosphate, phosphoinositides, signal transduction, second messengers s Abstract We review the physical properties of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) that determine both its specific interactions with protein domains of known structure and its nonspecific electrostatic sequestration by unstructured domains. Several investigators have postulated the existence of distinct pools of PIP 2 within the cell to account for the myriad functions of this
more » ... d functions of this lipid. Recent experimental work indicates certain regions of the plasma membrane-membrane ruffles and nascent phagosomes-do indeed concentrate PIP 2 . We consider two mechanisms that could account for this phenomenon: local synthesis and electrostatic sequestration. We conclude by considering the hypothesis that proteins such as MARCKS bind a significant fraction of the PIP 2 in a cell, helping to sequester it in lateral membrane domains, then release this lipid in response to local signals such as an increased concentration of Ca ++
doi:10.1146/annurev.biophys.31.082901.134259 pmid:11988466 fatcat:sqg5xcgiajhuhii6yy5h7e76qq