Comprehensive Lysine Ubiquitome Profiling Reveals Diverse Functions of Lysine Ubiquitination in Eimeria tenella.

Eimeria tenella is a parasitic protozoan with a direct lifecycle in a single host, but with diverse intermediate stages while developing in the host. Each E. tenella developmental stage has distinct structural, pathogenic, genetic, and protein expression, emerging from gene modifications and post-translational modifications (PTMs) of proteins. Ubiquitination regulates diverse cellular functions and activities. Until now, however, there have been sparse data on E. tenella ubiquitination except on some ubiquitin-related enzymes. It is pertinent to unveil the mechanism through which E. tenella developmental stages convert ubiquitin to its development. Herein, the ubiquitome of five life-stages (unsporulated oocyst, early stage of sporulation (i.e., 7 h into sporulation of the oocyst), sporulated oocyst, sporozoite, and second-generation merozoite) of E. tenella was investigated and compared. Correlation analysis of label-free quantitative proteomic and ubiquitomic data was performed. Ubiquitin proteomes were detected and dynamically expressed during the E. tenella oocyst sporulation process and other developmental stages. This implies that protein ubiquitination is perhaps a key regulator of parasite developmental transitions, biology, and pathogenicity. In brief, this study lays the foundation for future in-depth analysis and functional validation of the ubiquitin proteome and modified proteins in the life cycle of the avian parasite. The raw ubiquitome and parallel reaction monitoring (PRM) data sets are accessible via the iProX repository, assigned with accession numbers PXD043159 and PXD067512, respectively.