Deubiquitinases (DUBs) are vital for the regulation of ubiquitin signals, and both catalytic activity of and target recruitment by DUBs need to be tightly controlled. Here, we identify asparagine hydroxylation as a novel posttranslational modification involved in the regulation of Cezanne (also known as OTU domain-containing protein 7B (OTUD7B)), a DUB that controls key cellular functions and signaling pathways. We demonstrate that Cezanne is a substrate for factor inhibiting HIF1 (FIH1)- and oxygen-dependent asparagine hydroxylation. We found that FIH1 modifies Asn35 within the uncharacterized N-terminal ubiquitin-associated (UBA)-like domain of Cezanne (UBACez), which lacks conserved UBA domain properties. We show that UBACez binds Lys11-, Lys48-, Lys63-, and Met1-linked ubiquitin chains in vitro, establishing UBACez as a functional ubiquitin-binding domain. Our findings also reveal that the interaction of UBACez with ubiquitin is mediated via a noncanonical surface and that hydroxylation of Asn35 inhibits ubiquitin binding. Recently, it has been suggested that Cezanne recruitment to specific target proteins depends on UBACez Our results indicate that UBACez can indeed fulfill this role as regulatory domain by binding various ubiquitin chain types. They also uncover that this interaction with ubiquitin, and thus with modified substrates, can be modulated by oxygen-dependent asparagine hydroxylation, suggesting that Cezanne is regulated by oxygen levels.

中文翻译：

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塞尚中泛素相关（UBA）域的氧依赖性天冬酰胺羟化调节泛素结合。

去泛素酶（DUB）对于调节泛素信号至关重要，必须严格控制DUB的催化活性和靶标募集。在这里，我们确定天冬酰胺羟基化为一种新的翻译后修饰，参与调控塞尚（也称为OTU含域蛋白7B（OTUD7B）），一种控制关键细胞功能和信号通路的DUB。我们证明塞尚是抑制HIF1（FIH1）-和氧依赖性天冬酰胺羟基化因子的底物。我们发现FIH1修饰塞尚（UBACez）的未表征的N端泛素相关（UBA）样域内的Asn35（UBACez），它缺乏保守的UBA域属性。我们显示UBACez在体外结合Lys11-，Lys48-，Lys63-和Met1连接的泛素链，建立UBACez作为泛素结合功能域。我们的发现还表明，UBACez与泛素的相互作用是通过非规范表面介导的，而Asn35的羟基化作用会抑制泛素的结合。最近，有人提出塞尚要招募到特定的靶蛋白取决于UBACez。我们的结果表明UBACez确实可以通过结合各种泛素链类型来完成这一作为调节域的作用。他们还发现，这种与泛素的相互作用，因此与修饰的底物的相互作用，可以通过依赖氧的天冬酰胺羟化作用来调节，这表明塞尚受氧水平的调节。最近，有人提出塞尚要招募到特定的靶蛋白取决于UBACez。我们的结果表明UBACez确实可以通过结合各种泛素链类型来完成这一作为调节域的作用。他们还发现，这种与泛素的相互作用，因此与修饰的底物的相互作用，可以通过依赖氧的天冬酰胺羟化作用来调节，这表明塞尚受氧水平的调节。最近，有人提出塞尚要招募到特定的靶蛋白取决于UBACez。我们的结果表明UBACez确实可以通过结合各种泛素链类型来完成这一作为调节域的作用。他们还发现，这种与泛素的相互作用，因此与修饰的底物的相互作用，可以通过依赖氧的天冬酰胺羟化作用来调节，这表明塞尚受氧水平的调节。