Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA.
Channels (Austin). 2012 Nov-Dec;6(6):463-7. doi: 10.4161/chan.21939. Epub 2012 Sep 18.
Inorganic polyphosphate (polyP) is a naturally occurring polyanion made of ten to several hundred orthophosphates (P(i)) linked together by phosphoanhydride bonds. PolyP is ubiquitously present in all organisms from bacteria to humans. Specific physiological roles of polyP vary dramatically depending on its size, concentration, tissue and subcellular localization. Recently we reported that mitochondria of ventricular myocytes contain significant amounts (280 ± 60 pmol/mg of protein) of polyP with an average length of 25 orthophosphates, and that polyP is involved in Ca(2+)-dependent activation of the mitochondrial permeability transition pore (mPTP). Here we extend our study to demonstrate the involvement of mitochondrial polyP in cardiac cell death. Furthermore, we show that polyP levels depend on the activity of the respiratory chain and are lower in myocytes from failing hearts. We conclude that polyP is a dynamically regulated macromolecule that plays an important role in mPTP-dependent cell death pathway.
无机多聚磷酸盐（polyP）是一种由十个到几百个通过磷酸酐键连接在一起的正磷酸盐（P(i)）组成的天然多阴离子。多聚磷酸盐普遍存在于从细菌到人类的所有生物体中。多聚磷酸盐的特定生理作用因其大小、浓度、组织和亚细胞定位的不同而有很大差异。最近，我们报道了心室肌细胞的线粒体中含有大量（280 ± 60 pmol/mg 蛋白）多聚磷酸盐，其平均长度为 25 个正磷酸盐，并且多聚磷酸盐参与了钙（Ca(2+)）依赖性的线粒体通透性转换孔（mPTP）的激活。在这里，我们扩展了我们的研究，以证明线粒体多聚磷酸盐在心脏细胞死亡中的作用。此外，我们还表明，多聚磷酸盐的水平取决于呼吸链的活性，并且在衰竭心脏的肌细胞中较低。我们的结论是，多聚磷酸盐是一种动态调节的大分子，在 mPTP 依赖性细胞死亡途径中发挥重要作用。
