Cell Signaling & Neuroscience Inositol Phosphates

Slides Programmed Cell Death Activation and Inhibition of Apoptosis Mitochondria in Apoptosis ATM/p53 Signaling Pathway Caspase Cascade Caspase Activation Intrinsic Pathway Granzyme B FAS and Related Proteins Fas Signaling G1, and S Phases G2 and M Phases Regulatory Cascade The p53 Signaling Pathway Cytokines and Growth Factors Structures of Activin and Inhibin Structures of Chemokine Receptors Angiopoietins EGFR Signaling Pathway Transmembrane Precursors of EGF Possible Receptor Combos and Ligand Actions of Flt-3/Flk-2 Hedgehog and BMI1 IGF Regulation of Apoptosis IL-13 and IL-4 receptor IL-18 Production Neurotrophins and Their Receptors TrkA GDNF Family with Receptors PDGF Receptors and Actions TGF-beta Signaling BMP Signaling TNF Signaling TNF-α and TNF-β Proposed Balance Between TNF Superfamily Structure of Receptors VEGF Receptor and Ligands Prolactin Regulation Insulin Pathway Glucocorticoid Receptor Signaling Vascular Endothelial Cell Interactions Integrin Signaling in Cell Survival VEGF Receptor Signaling MMPs and Cytokines Events Leading to Angiogenesis Transcription Factors Nuclear Complex Targeting Jak/Stat Pathway STAT3 PPAR Formation of Nucleosomes DNA Compaction Early Response Events Cell Cycle Checkpoint Linkage between DNA Repair and Chromatin Modification Functions of WRN, BLM and MRE11 mRNP Transport Importinα - Importinβ Pathway Modular Structure of Transcription factors Transcription Activation by Nuclear Receptors Coupled RNA Splicing and Nuclear Export RNA Polyadenylation Mammalian mRNA Polyadenylation RNA Maturation Epigenetic Control Phosphorylation-driven Initiation-Elongation cAMP Metabolism cGMP Metabolism G-Protein Signaling T Cell Receptor B Cell Receptor Monovalent Ion Channels Activation/Inactivation Ligand-Gated Ion Channel Aquaporin Channel Structure Calcium Channel Structure Calcium Channel Pore Region Chloride Channel HCN Channel 2TM Potassium Channel Structure 6TM Potassium Channel Structure Sodium Channel Structure Sodium Channel Pore Region PTEN Pathway Lipids in Cell Signaling Inositol Phosphates Phosphatidic Acid Inositol Phospholipids ABC Transporters ABC-ATPases BSEP MRP1 β-Amyloid Plaques Notch Secretase Second Messenger Systems Limbic Reward Circuit Major Pathways in the CNS Endothelin Signaling NPY and Catecholamines Ascending Pain Pathway Modulation of Pain Transmission Mechanism of Action Fig. A Mechanism of Action Fig. B Drug Activation of Dopaminergic GABAB Receptor Oxidative Stress nNOS eNOS iNOS Nitric Oxide Proteasome/Ubiquitination Formation of Activated 20S Proteasome Ubiquitin Pathway MAP Kinase Cascades AKT Signaling Pathways Activated by VEGF

Inositol Phosphates

Inositol phosphates are important intracellular second messengers in eukaryotic cells. Inositol, a cyclic molecule with six hydroxyl groups, forms the hydrophobic head group of membrane inositol phospholipids. The actions of lipid kinases and phosphatases on the inositol ring of inositol phospholipids generate a variety of phosphoinositol phospholipids. As a result of upstream signaling events, specific phospholipases are activated, cleave phosphoinositol phospholipids, and release intracellular inositol phosphate second messenger molecules. The most studied inositol phosphate second messenger is inositol 1,4,5-trisphosphate (IP₃). IP₃ is released from phosphatidylinositol 4,5-bisphosphate (PIP₂) by the action of phospholipase C-b and is responsible for the release of calcium ions from intracellular stores in the endoplasmic reticulum.

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References:

Irvine, R.F., and Schell, M.J., Back in the water: the return of inositol phosphates. Nat. Rev. Mol. Cell Biol., 2, 327-338 (2001).

Shears, S.B., Assessing the omnipotence of inositol hexakisphosphate. Cell. Signal., 13, 151-158 (2001).