Arsenault Patrick R, Song Daisheng, Bergkamp Marian, Ravaschiere Andrew M, Navalsky Bradleigh E, Lieberman Paul M, Lee Frank S
Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA.
The Wistar Institute, 3601 Spruce St., Philadelphia, PA, 19104, USA.
Chembiochem. 2016 Dec 14;17(24):2316-2323. doi: 10.1002/cbic.201600493. Epub 2016 Nov 11.
The prolyl hydroxylase domain (PHD) protein:hypoxia inducible factor (HIF) pathway is the main pathway by which changes in oxygen concentration are transduced to changes in gene expression. In mammals, there are three PHD paralogues, and PHD2 has emerged as a particularly critical one for regulating HIF target genes such as erythropoietin (EPO), which controls red cell mass and hematocrit. PHD2 is distinctive among the three PHDs in that it contains an N-terminal MYND-type zinc finger. We have proposed that this zinc finger binds a Pro-Xaa-Leu-Glu (PXLE) motif found in proteins of the HSP90 pathway to facilitate HIF-α hydroxylation. Targeting this motif could provide a means of specifically inhibiting this PHD isoform. Here, we screened a library of chemical compounds for their capacity to inhibit the zinc finger of PHD2. We identified compounds that, in vitro, can inhibit PHD2 binding to a PXLE-containing peptide and induce activation of HIF. Injection of one of these compounds into mice induces an increase in hematocrit. This study offers proof of principle that inhibition of the zinc finger of PHD2 can provide a means of selectively targeting PHD2 to activate the HIF pathway.
脯氨酰羟化酶结构域（PHD）蛋白：缺氧诱导因子（HIF）通路是将氧浓度变化转化为基因表达变化的主要途径。在哺乳动物中，有三种PHD旁系同源物，其中PHD2已成为调节HIF靶基因（如控制红细胞量和血细胞比容的促红细胞生成素（EPO））的特别关键的一种。PHD2在三种PHD中独具特色，因为它含有一个N端MYND型锌指。我们提出，这个锌指与HSP90通路蛋白中发现的Pro-Xaa-Leu-Glu（PXLE）基序结合，以促进HIF-α羟化。靶向这个基序可能提供一种特异性抑制这种PHD亚型的方法。在此，我们筛选了一个化合物文库，以寻找其抑制PHD2锌指的能力。我们鉴定出了在体外可抑制PHD2与含PXLE肽结合并诱导HIF激活的化合物。将其中一种化合物注射到小鼠体内会导致血细胞比容升高。这项研究提供了原理证明，即抑制PHD2的锌指可提供一种选择性靶向PHD2以激活HIF通路的方法。
