Adv Biol Regul. 2015 Jan;57:203-16. doi: 10.1016/j.jbior.2014.09.015. Epub 2014 Oct 5.
Inositol pyrophosphates: why so many phosphates?
- 1
- Inositol Signaling Group, Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, NIH, DHHS, PO Box 12233, Research Triangle Park, NC 27709, USA. Electronic address: Shears@niehs.nih.gov.
Abstract
The inositol pyrophosphates
(PP-InsPs) are a specialized group of "energetic" signaling molecules
found in yeasts, plants and animals. PP-InsPs boast the most crowded
three dimensional phosphate arrays found in Nature; multiple phosphates
and diphosphates are crammed around the six-carbon, inositol
ring. Yet, phosphate esters are also a major energy currency in cells.
So the synthesis of PP-InsPs, and the maintenance of their levels in the
face of a high rate of ongoing turnover, all requires significant
bioenergetic input. What are the particular properties of PP-InsPs that
repay this investment of cellular energy? Potential answers to that
question are discussed here, against the backdrop of a recent hypothesis
that signaling by PP-InsPs is evolutionarily ancient. The latter idea
is extended herein, with the proposal that the primordial origins of
PP-InsPs is reflected in the apparent lack of isomeric specificity of
certain of their actions. Nevertheless, there are other aspects of
signaling by these polyphosphates that are more selective for a
particular PP-InsP isomer. Consideration of the nature of both specific
and non-specific effects of PP-InsPs can help rationalize why such
molecules possess so many phosphates.
Published by Elsevier Ltd.
KEYWORDS:
Analogs; Cell-signaling; Diphosphoinositol polyphosphates; Inositol pyrophosphates; Kinase; Phosphorylation; Structure- PMID:
- 25453220
- PMCID:
- PMC4291286
- DOI:
- 10.1016/j.jbior.2014.09.015
- [Indexed for MEDLINE]
KOSKA ON INOSITOLIPYROFOSFAATTEJA, on myös INOSITOLIPYROFOSFATAASEJA:
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