PDF(Pubmed)
Abstract：
The ubiquitination and proteasome-mediated degradation of Hypoxia Inducible Factors (HIFs) is central to metazoan oxygen-sensing, but the involvement of deubiquitinating enzymes (DUBs) in HIF signalling is less clear. Here, using a bespoke DUBs sgRNA library we conduct CRISPR/Cas9 mutagenesis screens to determine how DUBs are involved in HIF signalling. Alongside defining DUBs involved in HIF activation or suppression, we identify USP43 as a DUB required for efficient activation of a HIF response. USP43 is hypoxia regulated and selectively associates with the HIF-1α isoform, and while USP43 does not alter HIF-1α stability, it facilitates HIF-1 nuclear accumulation and binding to its target genes. Mechanistically, USP43 associates with 14-3-3 proteins in a hypoxia and phosphorylation dependent manner to increase the nuclear pool of HIF-1. Together, our results highlight the multifunctionality of DUBs, illustrating that they can provide important signalling functions alongside their catalytic roles.
摘要：
缺氧诱导因子（HIF）的泛素化和蛋白酶体介导的降解是后生动物氧敏感的核心，但是去泛素化酶（DUB）在HIF信号传导中的参与尚不清楚。这里,使用定制的DUBssgRNA文库，我们进行CRISPR/Cas9诱变筛选，以确定DUBs如何参与HIF信号传导。除了定义参与HIF激活或抑制的DUB，我们将USP43鉴定为有效激活HIF应答所需的DUB.USP43是缺氧调节的，并选择性地与HIF-1α同工型相关，虽然USP43不会改变HIF-1α的稳定性，它促进HIF-1核积累和与其靶基因的结合。机械上,USP43以缺氧和磷酸化依赖性方式与14-3-3蛋白结合以增加HIF-1的核库。一起,我们的结果强调了DUB的多功能性，说明它们可以提供重要的信号功能以及它们的催化作用。
