The Francis Crick Institute, London, United Kingdom.
Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom.
Elife. 2019 Sep 10;8:e46490. doi: 10.7554/eLife.46490.
Human and other animal cells deploy three closely related dioxygenases (PHD 1, 2 and 3) to signal oxygen levels by catalysing oxygen regulated prolyl hydroxylation of the transcription factor HIF. The discovery of the HIF prolyl-hydroxylase (PHD) enzymes as oxygen sensors raises a key question as to the existence and nature of non-HIF substrates, potentially transducing other biological responses to hypoxia. Over 20 such substrates are reported. We therefore sought to characterise their reactivity with recombinant PHD enzymes. Unexpectedly, we did not detect prolyl-hydroxylase activity on any reported non-HIF protein or peptide, using conditions supporting robust HIF-α hydroxylation. We cannot exclude PHD-catalysed prolyl hydroxylation occurring under conditions other than those we have examined. However, our findings using recombinant enzymes provide no support for the wide range of non-HIF PHD substrates that have been reported.
人和其他动物细胞通过催化转录因子 HIF 的氧调节脯氨酰羟化作用，利用三种密切相关的双氧酶（PHD1、2 和 3）来传递氧水平信号。作为氧传感器的 HIF 脯氨酰羟化酶（PHD）酶的发现提出了一个关键问题，即是否存在和性质非 HIF 底物，可能将其他生物反应转化为缺氧。已经报道了超过 20 种这样的底物。因此，我们试图用重组 PHD 酶来描述它们的反应性。出乎意料的是，我们在使用支持强大 HIF-α羟化的条件下，没有检测到任何报道的非 HIF 蛋白或肽的脯氨酰羟化酶活性。我们不能排除 PHD 催化的脯氨酰羟化作用在我们检查过的条件以外的条件下发生。然而，我们使用重组酶的发现结果并不支持已经报道的广泛的非 HIF PHD 底物。
