HSP90 is a target protein for ubiquitination in Giardia intestinalis

Previous studies have demonstrated the existence and expression of genes essential to the process of protein ubiquitination in Giardia intestinalis, indicating that the ubiquitin-proteasome system may be involved in the degradation of proteins during its life cycle of the parasite. In this study, purification of ubiquitin was conducted from protein extracts of G. intestinalis trophozoites. Then, an anti-ubiquitin specific antibody was obtained to standardize an assay for the detection and evaluation of ubiquitination patterns. Finally, HSP90 was identified as an ubiquitinated protein in this protozoan. This post-translational modification could have regulatory effects associated with the functionality of the protein or its turnover to regulate key molecular events during the parasite's life cycle.