Post-translational regulation of phosphatidylglycerolphosphate synthase in response to inositol
Post-translational regulation of phosphatidylglycerolphosphate synthase in response to inositol
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DOI：
10.1111/j.1365-2958.2004.04202.x
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发表时间：
2004-08-01
影响因子：
3.6
通讯作者：
Greenberg, ML
中科院分区：
文献类型：
--
作者：
He, Q;Greenberg, ML
磷脂酰甘油磷酸合酶（Pgs1p）催化心磷脂（CL）合成中的关键步骤。这是CL合成中唯一受肌醇调节的步骤。我们以前已经表明，Pgs1p酶活性在补充肌醇后几分钟内下降，但PGS1表达没有改变。我们利用表位标记的Pgs1p来确定肌醇后活性的快速降低是否是由于蛋白质的降解或失活。在这份报告中，我们表明，在响应肌醇，CL含量和PGS 1P酶活性的降低与PGS 1P的磷酸化增加，但不与降解或蛋白质的错误定位。这是磷脂生物合成酶磷酸化对肌醇的反应的第一个证据，并确定了肌醇介导的调节的新机制。
Phosphatidylglycerolphosphate synthase (Pgs1p) catalyses the committed step in the synthesis of cardiolipin (CL). This is the only step of CL synthesis that is regulated by inositol. We have shown previously that Pgs1p enzyme activity is decreased within minutes after supplementation with inositol, but PGS1 expression is unaltered. We utilized an epitope-tagged Pgs1p to determine if the rapid decrease in activity following inositol was because of degradation or inactivation of the protein. In this report, we show that, in response to inositol, the decrease in CL content and Pgs1p enzyme activity are associated with increased phosphorylation of Pgs1p, but not with degradation or mislocalization of the protein. This is the first evidence of phosphorylation of a phospholipid biosynthetic enzyme in response to inositol and identifies a new mechanism of inositol-mediated regulation.