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Gene duplication is a key frst step in the process of expanding the functionality of a multigene family. In order to better understand the process of gene duplication and its role in the formation of new enzymes, we investigated recent duplication events in the M14 family of proteolytic enzymes. Within vertebrates, four of 23 M14 genes were frequently found in duplicate form. While AEBP1, CPXM1, and CPZ genes were duplicated once through a large-scale, likely whole-genome duplication event, the CPO gene underwent many duplication events within fsh and Xenopus lineages. Bioinformatic analyses of enzyme specifcity and conservation suggested a greater amount of neofunctionalization and purifying selection in CPO paralogs compared with other CPA/B enzymes. To examine the functional consequences of evolutionary changes on CPO paralogs, the four CPO paralogs from Xenopus tropicalis were expressed in Sf9 and HEK293T cells. Immunocytochemistry showed subcellular distribution of Xenopus CPO paralogs to be similar to that of human CPO. Upon activation with trypsin, the enzymes demonstrated diferential activity against three substrates, suggesting an acquisition of new function following duplication and subsequent mutagenesis. Characteristics such as gene size and enzyme activation mechanisms are possible contributors to the evolutionary capacity of the CPO gene.

Journal Title

Scientific Reports






ISSN 2045-2322


First Department



Open access article retrieved 8/14/23 from:

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