How inositol pyrophosphates control cellular phosphate homeostasis?
Phosphorus in his phosphate PO(4)(3-) configuration is an essential constituent of all life forms. Phosphate diesters are at the core of nucleic acid structure, while phosphate monoester transmits information under the control of protein kinases and phosphatases. Due to these fundamental roles in biology it is not a surprise that phosphate cellular homeostasis is under tight control. Inositol pyrophosphates are organic molecules with the highest proportion of phosphate groups, and they are capable of regulating many biological processes, possibly by controlling energetic metabolism and adenosine triphosphate (ATP) production. Furthermore, inositol pyrophosphates influence inorganic polyphosphates (polyP) synthesis. The polymer polyP is solely constituted by phosphate groups and beside other known functions, it also plays a role in buffering cellular free phosphate [Pi] levels, an event that is ultimately necessary to generate ATP and inositol pyrophosphate. Although it is not yet clear how inositol pyrophosphates regulate cellular metabolism, understanding how inositol pyrophosphates influence phosphates homeostasis will help to clarify this important link. In this review I will describe the recent literature on this topic, with in the hope of inspiring further research in this fascinating area of biology.
Cell Biology Unit, Medical Research Council Laboratory for Molecular Cell Biology, Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK. dmcbado@ucl.ac.uk
Adolfo
A
Saiardi
D017766:Acid Anhydride Hydrolases / Q000378:metabolism; D000818:Animals; D006706:Homeostasis; D006801:Humans; D007295:Inositol Phosphates / Q000502:physiology*; D008954:Models, Biological; D010710:Phosphates / Q000378:metabolism*; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000378:metabolism; D011122:Polyphosphates / Q000378:metabolism; D011755:Pyrophosphatases / Q000378:metabolism; D000096964:Nudix Hydrolases
D017766:Acid Anhydride Hydrolases; D007295:Inositol Phosphates; D010710:Phosphates; D017856:Phosphotransferases (Phosphate Group Acceptor); D011122:Polyphosphates; D011755:Pyrophosphatases; D000096964:Nudix Hydrolases; C407349:diphosphoinositol pentakisphosphate kinase; C116368:diphosphoinositol polyphosphate phosphohydrolase