The Podospora anserina genome contains a large family of 15 multicopper oxidases (MCOs), including three genes encoding a FET3-like protein, an ABR1-like protein and an ascorbate oxidase (AO)-like protein. FET3, ABR1 and AO1 are involved in global laccase-like activity since deletion of the relevant genes led to a decrease of activity when laccase substrate (ABTS) was used as substrate. However, contrary to the P. anserina MCO proteins previously characterized, none of these three MCOs seemed to be involved in lignocellulose degradation and in resistance to phenolic compounds and oxidative stress. We showed that the bulk of ferroxidase activity was clearly due to ABR1, and only in minor part to FET3, although ABR1 does not contain all the residues typical of FET3 proteins. Moreover, we showed that ABR1, related to the Aspergillus fumigatus ABR1 protein, was clearly and specifically involved in pigmentation of ascospores. Surprisingly, phenotypes were more severe in mutants lacking both abr1 and ao1. Deletion of the ao1 gene led to an almost total loss of AO activity. No direct involvement of AO1 in fungal developmental process in P. anserina was evidenced, except in a abr1Δ background. Overall, unlike other previously characterized MCOs, we thus evidence a clear involvement of ABR1 protein in fungal development.

中文翻译：

---

丝状真菌Podospora anserina中三种多铜氧化酶的表征：类ABR1蛋白在真菌发育中的新作用？

Podospora anserina基因组包含15个多铜氧化酶（MCO）的大家族，包括编码FET3样蛋白，ABR1样蛋白和抗坏血酸氧化酶（AO）样蛋白的三个基因。FET3，ABR1和AO1参与了整体漆酶样活性，因为当将漆酶底物（ABTS）用作底物时，相关基因的缺失导致活性降低。然而，与先前表征的P. anserina MCO蛋白相反，这三种MCO似乎都不参与木质纤维素的降解以及对酚类化合物和氧化应激的抗性。我们表明，大量的亚铁氧化物酶活性显然是由于ABR1引起的，并且仅占FET3的一小部分，尽管ABR1并不包含FET3蛋白的所有典型残基。此外，我们证明了ABR1，与烟曲霉ABR1蛋白有关的蛋白明显和特异性地参与了子囊孢子的色素沉着。出人意料的是，在缺乏abr1和ao1的突变体中，表型更为严重。ao1基因的缺失导致AO活性几乎完全丧失。除了abr1Δ背景外，没有证据表明AO1直接参与了小球藻的真菌发育过程。总体而言，与其他先前表征的MCO不同，我们因此证明ABR1蛋白明显参与真菌发育。除了abr1Δ背景。总体而言，与其他先前表征的MCO不同，我们因此证明ABR1蛋白明显参与真菌发育。除了abr1Δ背景。总体而言，与其他先前表征的MCO不同，我们因此证明ABR1蛋白明显参与真菌发育。