Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, U.S.A.
Biochem Soc Trans. 2019 Feb 28;47(1):371-379. doi: 10.1042/BST20180473. Epub 2019 Feb 1.
Pseudoenzymes are noncatalytic homologues of enzymes and are found in most enzyme families. Although lacking catalytic activity and sometimes referred to as 'dead' enzymes, they instead resemble phoenixes because the loss of a catalytic function during evolution was associated with the development of vital new functions. They are important in regulating the activity and location of catalytically active homologues, scaffolding the assembly of signaling complexes, and regulating transcription or translation. They are key actors in cell proliferation and differentiation, proteostasis, and many other biochemical pathways and processes. They perform their functions in diverse ways, but many retain some aspects of the function of their catalytically active homologues. In some pseudoenzymes, their functions are very different from other members of their protein families, suggesting some arose from ancient moonlighting proteins during evolution. Much less is known about pseudoenzymes than their catalytically active counterparts, but a growing appreciation of their key roles in many important biochemical processes and signaling pathways has led to increased investigation in recent years. It is clear that there is still much more to learn about the structures, functions, and cellular roles of these phoenix-like proteins.
拟酶是非催化酶的同源物，存在于大多数酶家族中。尽管它们缺乏催化活性，有时也被称为“无活性”酶，但它们更像是凤凰，因为在进化过程中失去催化功能与开发重要的新功能有关。它们在调节催化同源物的活性和位置、支架信号复合物的组装以及调节转录或翻译方面起着重要作用。它们是细胞增殖和分化、蛋白稳态以及许多其他生化途径和过程的关键因素。它们通过多种方式发挥作用，但许多仍保留其催化同源物功能的某些方面。在一些拟酶中，它们的功能与其蛋白质家族的其他成员非常不同，这表明它们是在进化过程中从古老的多功能蛋白中产生的。人们对拟酶的了解远不及催化活性酶，但近年来，人们越来越认识到它们在许多重要的生化过程和信号通路中的关键作用，这促使人们对其进行了更多的研究。显然，关于这些类似凤凰的蛋白的结构、功能和细胞作用，还有很多需要了解。
