Shears Stephen B
Inositol Signaling Section, Laboratory of Signal Transduction, NIEHS/NIH/DHSS Research Triangle Park, NC 27709, USA.
Biochem J. 2004 Jan 15;377(Pt 2):265-80. doi: 10.1042/BJ20031428.
This review assesses the extent and the significance of catalytic versatility shown by several inositol phosphate kinases: the inositol phosphate multikinase, the reversible Ins(1,3,4) P (3)/Ins(3,4,5,6) P (4) kinase, and the kinases that synthesize diphosphoinositol polyphosphates. Particular emphasis is placed upon data that are relevant to the situation in vivo. It will be shown that catalytic promiscuity towards different inositol phosphates is not typically an evolutionary compromise, but instead is sometimes exploited to facilitate tight regulation of physiological processes. This multifunctionality can add to the complexity with which inositol signalling pathways interact. This review also assesses some proposed additional functions for the catalytic domains, including transcriptional regulation, protein kinase activity and control by molecular 'switching', all in the context of growing interest in 'moonlighting' (gene-sharing) proteins.
本综述评估了几种肌醇磷酸激酶所表现出的催化多功能性的程度及其重要性，这些激酶包括肌醇磷酸多激酶、可逆的Ins(1,3,4)P₃/Ins(3,4,5,6)P₄激酶以及合成二磷酸肌醇多磷酸的激酶。特别强调了与体内情况相关的数据。结果将表明，对不同肌醇磷酸的催化混杂性通常并非进化上的妥协，相反，有时会利用这种特性来促进对生理过程的严格调控。这种多功能性会增加肌醇信号通路相互作用的复杂性。本综述还在对“兼职”（基因共享）蛋白的兴趣日益浓厚的背景下，评估了催化结构域的一些其他 proposed 功能，包括转录调控、蛋白激酶活性以及通过分子“开关”进行的控制。
