Differential regulation of multi-copper oxidases in Schizophyllum commune during sexual development

Multi-copper oxidases (MCOs) are enzymes accepting a wide range of organic and inorganic substrates. MCOs (including laccases) in lignolytic white and brown rot fungi are represented by multiple members of gene families that have different roles in fungal sexual and asexual development as well as in lignin degradation. Differential regulation of the two laccases (Lcc1 and Lcc2) and four laccase-like (Mco1 through Mco4) MCOs in S. commune were analyzed and correlated with morphogenetic processes during sexual development. Transcripts of lcc2 were found to accumulate in the monokaryotic mycelia and showed up-regulation during the dikaryotic phase. Gene mco2 was up-regulated in the primordial and fruiting phases and mco3 was expressed mainly in fruiting bodies. Enzymatic activities were indeed higher in dikaryons and during fruiting. Regulatory promoter elements were determined to be in agreement with stress responses for the remaining genes. Homology-based protein models were used to identify subfamily associations via a similar potential domain structure, including predicted sites of post-translation modifications. Thus, we could assign different functions in development to members of this protein family.