脂质磷酸二酯酶 2 通过静电氢键开关机制与磷酸化无关结合磷酸酰基。
Lipin 2 binds phosphatidic acid by the electrostatic hydrogen bond switch mechanism independent of phosphorylation.
机构信息
From the Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908.
the Department of Genome Sciences, University of Washington, Seattle, Washington 98105.
出版信息
J Biol Chem. 2014 Jun 27;289(26):18055-66. doi: 10.1074/jbc.M114.547604. Epub 2014 May 8.
Lipin 2 is a phosphatidic acid phosphatase (PAP) responsible for the penultimate step of triglyceride synthesis and dephosphorylation of phosphatidic acid (PA) to generate diacylglycerol. The lipin family of PA phosphatases is composed of lipins 1-3, which are members of the conserved haloacid dehalogenase superfamily. Although genetic alteration of LPIN2 in humans is known to cause Majeed syndrome, little is known about the biochemical regulation of its PAP activity. Here, in an attempt to gain a better general understanding of the biochemical nature of lipin 2, we have performed kinetic and phosphorylation analyses. We provide evidence that lipin 2, like lipin 1, binds PA via the electrostatic hydrogen bond switch mechanism but has a lower rate of catalysis. Like lipin 1, lipin 2 is highly phosphorylated, and we identified 15 phosphosites. However, unlike lipin 1, the phosphorylation of lipin 2 is not induced by insulin signaling nor is it sensitive to inhibition of the mammalian target of rapamycin. Importantly, phosphorylation of lipin 2 does not negatively regulate either membrane binding or PAP activity. This suggests that lipin 2 functions as a constitutively active PA phosphatase in stark contrast to the high degree of phosphorylation-mediated regulation of lipin 1. This knowledge of lipin 2 regulation is important for a deeper understanding of how the lipin family functions with respect to lipid synthesis and, more generally, as an example of how the membrane environment around PA can influence its effector proteins.
脂联素 2 是一种磷酸脂酶 (PAP),负责甘油三酯合成的倒数第二步,以及将磷酸脂酸 (PA) 去磷酸化生成二酰基甘油。PA 磷酸酶的脂联素家族由脂联素 1-3 组成,它们是保守的卤酸脱卤酶超家族的成员。尽管已知人类 LPIN2 的遗传改变会导致 Majeed 综合征,但对其 PAP 活性的生化调节知之甚少。在这里,我们试图更好地了解脂联素 2 的生化性质,进行了动力学和磷酸化分析。我们提供的证据表明,脂联素 2 像脂联素 1 一样,通过静电氢键开关机制结合 PA,但催化速率较低。与脂联素 1 一样,脂联素 2 高度磷酸化,我们鉴定了 15 个磷酸化位点。然而,与脂联素 1 不同,胰岛素信号不会诱导脂联素 2 的磷酸化,也不会对哺乳动物雷帕霉素靶蛋白的抑制敏感。重要的是,脂联素 2 的磷酸化不会负调节膜结合或 PAP 活性。这表明,脂联素 2 作为一种组成性活性的 PA 磷酸酶发挥作用,与脂联素 1 的高度磷酸化介导的调节形成鲜明对比。对脂联素 2 调节的了解对于更深入地了解脂联素家族在脂质合成方面的功能以及更普遍地了解 PA 周围膜环境如何影响其效应蛋白的功能非常重要。
相似文献
Prog Lipid Res. 2013-4-17
Biochem Pharmacol. 2024-4
Proc Natl Acad Sci U S A. 2012-12-24
引用本文的文献
Biochim Biophys Acta Mol Cell Biol Lipids. 2024-12
Lipids Health Dis. 2023-11-14
Nat Commun. 2021-8-5
Nat Commun. 2020-3-11
本文引用的文献
Prog Lipid Res. 2013-4-17
Proc Natl Acad Sci U S A. 2012-8-20
BMC Biol. 2011-12-2