PIP2 phosphatidylinositol

Figure 4 Schematic representation of the Ca2+-transporting systems affecting cellular calcium homeostasis during hormonal stimulation, oq = oq-adrenergic receptor VP = vasopressin receptor PLC = phospholipase C PI = phosphatidylinositol PIP = phospha-tidylinositol-4-phosphate PIP2 = phosphatidylinositol-4,5-biphosphate IP3 = inositol-1,4,5-triphosphate DG = diacylglycerol PKC = protein kinase C. (Modified from Refs. 125 and 285.)...

PIP2 phosphatidylinositol 4,5-bisphosphate SAICAR succinylaminoimidazole carboxamide ribotide... 

Figure 14-3. Signaling through protein kinase C (PKC). Activated phospholipase C cleaves the inositol phospholipid PIP2 to form both soluble (IP3) and membrane-associated (DAG) second messengers. DAG recruits PKC to the membrane, where binding of calcium ions to PKC fully activates it. To accomplish this, IP3 promotes a transient increase of intracellular concentration by binding to a receptor on the endoplasmic reticulum, which opens a channel allowing release of stored calcium ions. PIP2, phosphatidylinositol 4,5-bisphosphate DAG, diacylglycerol PLC, phospholipase C IP3, inositol trisphosphate.

IP3 = 1,4,5-inositol triphosphate PI = phosphatidylinositol PIP = phosphatidylinositol phosphate PIP2 = phosphatidylinositol 4,5-biphosphate PKC = protein kinase C PLC = phosphohpase C R = receptor T = transporter. 

Figure 1.11 Pathways involved in phospholipase C (PLC) cellular signalling. PKA, protein kinase A or cAMP-dependent protein kinases PKC, protein kinase C PI, phosphatidylinositol PIP2, phosphatidylinositol bis-phosphate IP3, inositol triphosphate IP, inositol phosphate DAG, diacylglycerol.

The Ca2+-phosphoinositide signaling pathway. Key proteins include hormone receptors (R), a G protein (G), a phosphoinositide-specific phospholipase C (PLC), protein kinase C substrates of the kinase (S), calmodulin (CaM), and calmodulin-binding enzymes (E), including kinases, phosphodiesterases, etc. (PIP2, phosphatidylinositol-4,5-bisphosphate DAG, diacylglycerol. Asterisk denotes activated state. Open arrows denote regulatory effects.)... 

Effect of lithium on the IP3 and DAG second-messenger system. The schematic diagram shows the synaptic membrane of a neuron. (PIP2, phosphatidylinositol-4,5-bisphosphate PLC, phospholipase-C G, coupling protein EFFECTS, activation of protein kinase C, mobilization of intracellular Ca2+, etc.) Lithium, by inhibiting the recycling of inositol substrates, may cause... 

Abbreviations AA, arachidonic acid LA, linoleic acid OA, oleic acid PA, palmitic acid PC, phosphatidylcholine PE, phosphatidylethanolamine PIP2, phosphatidylinositol 4,5-bisphosphate. 

Fig. 2. Targeted lipidomics of 2-AG metabolism. Postulated pathways for 2-AG metabolism. Abbreviations PLC, phospholipase C DAG, diacylglycerol DGL, diacylglycerol lipase MGL, monoacylglycerol lipase PLA, phospholipase A AT, acyltransferase TAGL, triacylglycerol lipase PIP2, phosphatidylinositol bisphosphate ABHD-6/12 hydrolase lyso-PL, lysophospholipid lyso-PA, lysophosphatidic acid PA, phosphatidic add P, phosphatase COX, cydooxygen-ase LOX, lipoxygenase CYP450, cytochrome P450 CDP, cytidine diphosphate.

Fig. 5.2 Early G-protein signaling events at the AT]R. Phospholipases C and D are sequentially activated by heterotrimeric G-protein subunits to produce important second messengers such as IP3 and DAG. See text for details. ATiR, angiotensin II type 1 receptor DAG, diacylglycerol IP3, inositol 1,4,5-trisphosphate PA, phosphatidic acid PC, phosphatidylcholine PIP2, phosphatidylinositol-4,5-bisphosphate PKC, protein kinase C PLC, phospholipase C PLD, phospholipase D.

Abbreviations [Ca2+]j, intracellular Ca2+ concentration as measured by a Ca2 indicator such as ae-quorin [Ca2+]c, Ca2+ concentration in the bulk cytosol (hypothetical value) [Ca2 f]sm, Ca2 concentration in submembrane domain just beneath the plasma membrane (a hypothetical value) PI, phospha-tidylinositol PIP2, phosphatidylinositol 4,5-bisphosphate PIP, phosphatidylinositol 4-phosphate Insl,4,5,P3, inositol 1,4,5,-trisphosphate Ins 1,3,4,P, inositol 1,3,4-trisphosphate Insl,3,4,5P4, inositol 1,3,4,5-tetrakisphosphate Insl,4P2, inositol 1,4-bisphosphate CaM, calmodulin C-kinase, protein kinase C [cAMP]c, cAMP concentration in the bulk cytosol [cAMP]sm, cAMP concentration in submembrane domain just beneath the plasma membrane. 

Fig. 1. A compact visual summary of the signaling of cytoplasmic/nuclear and cell surface receptors. ER, endoplasmic reticulum M, mitochondrion PIP2, phosphatidylinositol-4,5-diphosphate IP3, inositol triphosphate PK, protein kinase, second messenger.

Fig. 11.1 Products of phospholipase hydrolytic activity on phospholipid substrate. PC, phosphatidylcholine AA, arachidonic acid LPC, lysophosphatidic acid PA, phosphatidic acid PIP2, phosphatidylinositol 4,5-bisphosphate DAG, diacylglycerol IP3, inositol 1,4,5-trisphosphate PLA2, Phospholipase A2 PLC, Phospholipase C PLD, Phospholipase D...

Figure 12 CKR signaling. CKRs preferentially signal via Gai/o proteins and recruit p-arrestin upon receptor activation. Abbreviations AC, adenylyl cyclase ATP, adenosine triphosphate cAMP, cyclic adenosine monophosphate CRE, cAMP-responsive element DAG, diacylglycerol Epac, exchange proteins activated by cAMP GRK, G protein-coupled receptor kinase IP3, inositol 1,4,5-triphosphate NFAT, nuclear factor of activated T-cells PIP2, phosphatidylinositol-4,5-bisphosphate PKA, protein kinase A PKC, protein kinase C PLC-p, phospholipase C-p.

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