Nicotinic acetylcholine receptors mediate fast synaptic transmission by fluxing ions across the membrane in response to neurotransmitter binding. We show here that during affinity purification of the nicotinic acetylcholine receptor from Torpedo, phosphatidic acid, but not other anionic or zwitterionic phospholipids, is hydrolyzed to diacylglycerol. The phospholipase C activity elutes with the ...

Bazooka (Par-3) is a conserved polarity regulator that organizes molecular networks in a wide range of cell types. In epithelia, it functions as a plasma membrane landmark to organize the apical domain. Bazooka is a scaffold protein that interacts with proteins through its three PDZ (postsynaptic density 95, discs large, zonula occludens-1) domains and other regions. In addition, Bazooka has be...

PDZGEF is a guanine nucleotide exchange factor for the small G protein Rap. It was recently found that PDZGEF contributes to establishment of intestinal epithelial polarity downstream of the kinase Lkb1. By binding to phosphatidic acid enriched at the apical membrane, PDZGEF locally activates Rap2a resulting in induction of brush border formation via a pathway that includes the polarity players...

Recent studies suggest that signal-dependent formation of phosphatidic acid by phospholipase D-catalyzed hydrolysis of phosphatidylcholine is a novel trans-membrane signaling pathway in mammalian cells. We here demonstrate that sphingosine, as well as some other long chain bases, activates phospholipase D in neural-derived NG108-15 cells. Sphingosine potently stimulated phosphatidic acid and, i...

1. The presence of palmitoyl-CoA-l-glycerol 3-phosphate palmitoyltransferase (EC 2.3.1.15) has been demonstrated in a particulate fraction of mammary tissue from lactating guinea pigs. 2. Cell-free preparations also catalysed the activation of palmitate and oleate, and the conversion of enzymically formed phosphatidic acid into glycerides, in accord with the Kennedy pathway of glyceride formati...

“Light” nerve endings from guinea pig cerebral cortex were incubated with [32P]orthophosphate, myo[3H]inositol, [3H]glycerol, or [3H]glucose in the presence or absence of cholinergic agents. Acetylcholine and carbamylcholine increased incorporation of “Pi into phosphatidic acid 100% and into various classes of phosphatidylinositol 20 to 70%. These agents also stimulated the labeling of phosphat...

The calmodulin antagonist trifluoperazine inhibits many responses of human platelets to stimuli such as thrombin. We have now demonstrated that trifluoperazine inhibits the production of all arachidonic acid metabolites, by both cyclooxygenase and lipoxygenase pathways, in thrombin-stimulated platelets. The metabolism of exogenously supplied arachidonlc acid was not affected by trifluoperazine....

The structural and functional properties of reconstituted nicotinic acetylcholine receptor membranes composed of phosphatidyl choline either with or without cholesterol and/or phosphatidic acid have been examined to test the hypothesis that receptor conformational equilibria are modulated by the physical properties of the surrounding lipid environment. Spectroscopic and chemical labeling data i...

Timely activation of Aurora kinase A (AURA, also known as AURKA) is vital for centrosome formation and the progression of mitosis. Nonetheless, it is still unclear if and when other cellular functions are activated by AURA. We report here that Src phosphorylates and activates AURA at T288, and AURA also activates focal adhesion kinase (FAK, also known as PTK2), leading to initiation of cell mov...