Signaling Role of Inositol and its Phosphates

Abstract

Inositol and its phosphates are integral parts of cellular signaling. InsP₆ is plentiful in organisms as diverse as yeast, actinobacteria, mammals and plants. In the plant kingdom, InsP₆ accumulates during seed development; at the time of germination it is broken down into lower inositol phosphates and micronutrients to maintain seedling. InsP₆ is the most abundant of intracellular inositol phosphates in eukaryotes. In mammals InsP₆ maintains homeostasis, stores phosphate and acts as strong antioxidant and neurotransmitter. InsP₆ and other inositol phosphates including the pyrophosphates, play critical roles in cellular pathways involved in signal transduction, control of cell proliferation and differentiation, RNA export, DNA repair, energy transduction, ATP regeneration etc. By enabling communication between nucleus, cytoplasm, and the outside environment, InsP₆ and the other inositol phosphates play a crucial role in many aspects of cell biology.

Keywords: Apoptosis, ATP, auxin, cell proliferation, clathrin, coated pits, differentiation, DNA repair, eukaryote, exocytosis, FGF, MAPK, nuclear pore, PKC, prokaryote, RNA export, signal transduction, syndecan, zinc finger.