Inositolpolyphosphates and their binding proteins--a short review.
Since 1983, when it was discovered that inositol 1,4,5-trisphosphate can act as second messenger to release Ca2+ from the endoplasmic reticulum, widespread research has focused on the phosphatidylinositol signalling transduction pathway and the host of inositolphosphates formed intracellularly after stimulation therof. Although the polyphosphates, inositoltetrakisphosphate (InsP4) and inositolhexakisphosphate (InsP6), have received their share of attention, a definite physiological role has not been ascribed to them as yet. Different binding proteins for these two polyphosphates have been demonstrated, especially in brain tissue, indicating their possible importance in the cell. InsP6 is known as one of nature's most powerful antioxidants and has already been demonstrated to possess the abilities to be of use in the industry as well as in the medical profession. As its natural actions are poorly understood and its possible side-effects have not been widely investigated, basic research regarding its cellular and subcellular activities is urgently called for.
Huisamen
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Department of Medical Physiology and Biochemistry, Faculty of Medicine, University of Stellenbosch, Tygerberg; Republic of South Africa.
Lochner
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D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use; D000975:Antioxidants; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology*; D002352:Carrier Proteins / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D003110:Colonic Neoplasms / Q000517:prevention & control; D019204:GTP-Binding Proteins / Q000502:physiology; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D010833:Phytic Acid / Q000378:metabolism* / Q000627:therapeutic use; D011941:Receptors, Adrenergic / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology*; D015290:Second Messenger Systems; D015398:Signal Transduction
D016588:Anticarcinogenic Agents; D000975:Antioxidants; D015220:Calcium Channels; D002352:Carrier Proteins; C506926:ITPR1 protein, human; D053496:Inositol 1,4,5-Trisphosphate Receptors; D011941:Receptors, Adrenergic; D018160:Receptors, Cytoplasmic and Nuclear; D010833:Phytic Acid; D015544:Inositol 1,4,5-Trisphosphate; D019204:GTP-Binding Proteins; D002118:Calcium