Saiardi Adolfo
MRC-LMCB, Department of Cell and Developmental Biology, University College London, Gower Street, WC1E 6BT, London, UK,
Subcell Biochem. 2012;59:413-43. doi: 10.1007/978-94-007-3015-1_14.
Inositol serves as a module for the generation of a high level of molecular diversity through the combinatorial attachment and removal of phosphate groups. The array of potential inositol-containing molecules is further expanded by the generation of diphospho inositol polyphosphates, commonly referred as inositol pyrophosphates. All eukaryotic cells possess inositol pyrophosphates containing one or more diphospho- moieties. The metabolism of this class of molecules is highly dynamic, and the enzymes responsible for their metabolism are evolutionary conserved. This new, exciting class of molecules are uniquely chracterized by a high energetic diphospho- bound that is able to participate in phosphotrasfer reactions thereby generating pyrophosphorylation of protein. However, allosteric mechanisms of action have been also proposed. In the past decade several disparate nuclear and cytoplasmic functions have been attributed to inositol pyrophosphates, ranging from intracellular trafficking to telomere length control and from regulating apoptotic process to stimulating insulin secretion. The extraordinary range of cellular function controlled by inositol pyrophosphate underline their great importance.
肌醇作为一个模块，通过磷酸基团的组合连接和去除来产生高水平的分子多样性。二磷酸肌醇多磷酸（通常称为肌醇焦磷酸）的产生进一步扩大了潜在含肌醇分子的阵列。所有真核细胞都拥有含有一个或多个二磷酸部分的肌醇焦磷酸。这类分子的代谢高度动态，负责其代谢的酶在进化上是保守的。这类新的、令人兴奋的分子的独特特征是具有高能二磷酸键，能够参与磷酸转移反应，从而产生蛋白质的焦磷酸化。然而，也有人提出了变构作用机制。在过去十年中，肌醇焦磷酸被认为具有多种不同的核和细胞质功能，从细胞内运输到端粒长度控制，从调节凋亡过程到刺激胰岛素分泌。肌醇焦磷酸所控制的细胞功能范围之广突显了它们的重要性。
