Abstract
Ubiquitin-specific protease (UBP) family is the largest group of deubiquitinases, which plays important roles in eukaryotic organisms. Comprehensive analysis of UBP genes has not been conducted in the plant pathogenic fungi. In this study, 11 putative UBP genes were identified and characterized in the rice blast fungus Magnaporthe oryzae. Expression profile analysis showed that UBP3, UBP6, UBP12 and UBP14 were highly expressed in different tissues of M. oryzae. In all ubp mutants, especially Δubp3, Δubp12 and previously reported Δubp14, the ubiquitination levels were evidently elevated, which is consistent with their molecular roles in de-ubiquitination. The Δubp1, Δubp3, Δubp4, Δubp8 and Δubp14 mutants were reduced in colony growth. Most of the ubp mutants were severely reduced in conidia production capacity, indicating important roles of the UBPs in conidia formation. Except for Δubp2 and Δubp16, all of the other mutants were decreased in virulence to host plants and defective in invasive growth. These ubp mutants also induced massive ROS accumulation in host cells. We also found that the UBPs may function as both positive and negative regulators in stress response and nutrient utilization of M. oryzae. Collectively, UBPs are important for development, stress response, nutrient utilization and infection of M. oryzae.
Highlights
Ubiquitination is one of the most important posttranslational modifications, which plays central roles in diverse cellular pathways such as cell-cycle progression, signal transduction, DNA repair and endocytosis and apoptosis (Hershko and Ciechanover 1998; Pickart and Eddins 2004; Dikic et al 2009)
Identification of the Ubiquitin-specific protease (UBP) family proteins in M. oryzae To carry out a genome-wide identification of the UBP protein family in M. oryzae, S. cerevisiae UBP protein sequences were used as queries to search against the protein database available in the Magnaporthe genome
The phylogenetic dendrogram shows that, for most cases, M. oryzae UBP proteins are evenly distributed among these clades, implying that genes in the clade may have evolved from a copy of their common fungal ancestor (Fig. 1b)
Summary
Ubiquitination is one of the most important posttranslational modifications, which plays central roles in diverse cellular pathways such as cell-cycle progression, signal transduction, DNA repair and endocytosis and apoptosis (Hershko and Ciechanover 1998; Pickart and Eddins 2004; Dikic et al 2009). Ubiquitins can be removed from proteins, which is important for regulation of different cellular processes. Cellular ubiquitin monomers are kept in homeostasis by processing from ubiquitin precursors or deubiquitinating from protein substrates (Amerik and Hochstrasser 2004; Nijman et al 2005). These processes are regulated by the de-ubiquitinating enzymes (DUBs), which can remove ubiquitin moiety. The cleavage of ubiquitin from proteins by DUBs can affect the activity and fate of substrates
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
